Current Status and Historical Trends of Brown Tide and Red Tide ...

Current Status and Historical Trendsof Brown Tide and Red TidePhytoplankton Blooms in the CorpusChristi Bay National EstuaryProgram Study AreaCorpus Christi Bay National Estuary ProgramCCBNEP-07 • January 1996

This project has been funded in part by the United States EnvironmentalProtection Agency under assistance agreement #CE-9963-01-2 to the TexasNatural Resource Conservation Commission. The contents of this documentdo not necessarily represent the views of the United States EnvironmentalProtection Agency or the Texas Natural Resource ConservationCommission, nor do the contents of this document necessarily constitute theviews or policy of the Corpus Christi Bay National Estuary ProgramManagement Conference or its members. The information presented isintended to provide background information, including the professionalopinion of the authors, for the Management Conference deliberations whiledrafting official policy in the Comprehensive Conservation andManagement Plan (CCMP). The mention of trade names or commercialproducts does not in any way constitute an endorsement or recommendationfor use.

Current Status and Historical Trends ofBrown Tide and Red Tide Phytoplankton Blooms in theCorpus Christi Bay National Estuary ProgramStudy AreaDr. Edward J. BuskeyPrincipal InvestigatorContributors:Mr. Scott StewartMr. Jay PetersonMr. Christopher CollumbMarine Science InstituteThe University of Texas at AustinP.O. Box 1267Port Aransas, Texas 78373512/749-6794512/749-6777 FAXPublication CCBNEP-07January 1996

Policy CommitteeCommissioner John BakerPolicy Committee ChairTexas Natural ResourceConservation CommissionMr. Ray AllenCoastal CitizenThe Honorable Vilma LunaTexas RepresentativeThe Honorable Josephine MillerCounty Judge, San Patricio CountyThe Honorable Mary RhodesMayor, City of Corpus ChristiMs. Jane SaginawPolicy Committee Vice-ChairRegional Administrator, EPA Region 6Commissioner John ClymerTexas Parks and Wildlife DepartmentCommissioner Garry MauroTexas General Land OfficeMr. Bernard PaulsonCoastal CitizenThe Honorable Carlos TruanTexas SenatorManagement CommitteeMr. Dean Robbins, Co-Chair Mr. William H. Hathaway, Co-ChairLocal Governments Advisory CommitteeMr. James Dodson, Chair Commissioner Gordon Porter, Vice-ChairScientific/Technical Advisory CommitteeDr. Terry Whitledge, Chair Dr. Wes Tunnell, Vice-ChairCitizens Advisory CommitteeMr. William Goldston, Co-Chair Mr. John Hendricks, Co-ChairFinancial Planning Advisory CommitteeDr. Joe Mosely, ChairProgram DirectorMr. Richard VolkTAMU-CC Campus Box 290 • 6300 Ocean Drive • Corpus Christi, TX 78412512/985-6767 • FAX 512/985-6301 • CCBNEP home page: //www.sci.tamucc.edu/ccbnepiii

Barry R. McBee, ChairmanR. B. Ralph Marquez, CommissionerJohn M. Baker, CommissionerDan Pearson, Executive DirectorAuthorization for use or reproduction of any original material contained inthis publication, i.e., not obtained from other sources, is freely granted. TheCommission would appreciate acknowledgment.Published and distributedby theTexas Natural Resource Conservation CommissionPost Office Box 13087Austin, Texas 78711-3087The TNRCC is an equal opportunity/affirmative action employer. The agency does not allow discrimination on the basis of race, color,religion, national origin, sex, disability, age, sexual orientation or veteran status. In compliance with the Americans with Disabilities Act,this document may be requested in alternate formats by contacting the TNRCC at (512) 239-0010, Fax 239-0055 or 1-800-RELAY-TX(TDD), or by writing P.O. Box 13087, Austin, TX 78711- 3087.iv

CORPUS CHRISTI BAY NATIONAL ESTUARY PROGRAMThe Corpus Christi Bay National Estuary Program (CCBNEP) is a four-year,community based effort to identify the problems facing the bays and estuaries of theCoastal Bend, and to develop a long-range, Comprehensive Conservation andManagement Plan. The Program's fundamental purpose is to protect, restore, or enhancethe quality of water, sediments, and living resources found within the 600 square mileestuarine portion of the study area.The Coastal Bend bay system is one of 28 estuaries that have been designated as anEstuary of National Significance under a program established by the United StatesCongress through the Water Quality Act of 1987. This bay system was so designated in1992 because of its benefits to Texas and the nation. For example:• Corpus Christi Bay is the gateway to the nation's sixth largest port, and home to thethird largest refinery and petrochemical complex. The Port generates over $1 billionof revenue for related businesses, more than $60 million in state and local taxes, andmore than 31,000 jobs for Coastal Bend residents.• The bays and estuaries are famous for their recreational and commercial fisheriesproduction. A study by Texas Agricultural Experiment Station in 1987 found thatthese industries, along with other recreational activities, contributed nearly $760million to the local economy, with a statewide impact of $1.3 billion, that year.• Of the approximately 100 estuaries around the nation, the Coastal Bend ranks fourthin agricultural acreage. Row crops -- cotton, sorghum, and corn -- and livestockgenerated $480 million in 1994 with a statewide economic impact of $1.6 billion.• There are over 2600 documented species of plants and animals in the Coastal Bend,including several species that are classified as endangered or threatened. Over 400bird species live in or pass through the region every year, making the Coastal Bendone of the premier bird watching spots in the world.The CCBNEP is gathering new and historical data to understand environmental statusand trends in the bay ecosystem, determine sources of pollution, causes of habitatdeclines and risks to human health, and to identify specific management actions to beimplemented over the course of several years. The 'priority issues' under investigationinclude:• altered freshwater inflow • degradation of water quality• declines in living resources • altered estuarine circulation• loss of wetlands and other habitats • selected public health issues• bay debrisThe COASTAL BEND BAYS PLAN that will result from these efforts will be thebeginning of a well-coordinated and goal-directed future for this regional resource.v

STUDY AREA DESCRIPTIONThe CCBNEP study area includes three of the seven major estuary systems of the TexasGulf Coast. These estuaries, the Aransas, Corpus Christi, and Upper Laguna Madre areshallow and biologically productive. Although connected, the estuaries arebiogeographically distinct and increase in salinity from north to south. The LagunaMadre is unusual in being only one of three hypersaline lagoon systems in the world.The study area is bounded on its eastern edge by a series of barrier islands, including theworld's longest -- Padre Island.Recognizing that successful management of coastal waters requires an ecosystemsapproach and careful consideration of all sources of pollutants, the CCBNEP study areaincludes the 12 counties of the Coastal Bend: Refugio, Aransas, Nueces, San Patricio,Kleberg, Kenedy, Bee, Live Oak, McMullen, Duval, Jim Wells, and Brooks.This region is part of the Gulf Coast and South Texas Plain, which are characterized bygently sloping plains. Soils are generally clay to sandy loams. There are three majorrivers (Aransas, Mission, and Nueces), few natural lakes, and two reservoirs (LakeCorpus Christi and Choke Canyon Reservoir) in the region. The natural vegetation is amixture of coastal prairie and mesquite chaparral savanna. Land use is largely devoted torangeland (61%), with cropland and pastureland (27%) and other mixed uses (12%).The region is semi-arid with a subtropical climate (average annual rainfall varies from 25to 38 inches, and is highly variable from year to year). Summers are hot and humid,while winters are generally mild with occasional freezes. Hurricanes and tropical stormsperiodically affect the region.On the following page is a regional map showing the three bay systems that comprise theCCBNEP study area.vi

PrefaceThe following report has been an attempt to bring together all available information onharmful algal blooms, commonly referred to as brown and red tides, in the CorpusChristi Bay National Estuary Program (CCBNEP) area. Since the number of publishedstudies on this subject is very small, especially if only studies from within the CCBNEParea are included, unpublished data and data from non-peer reviewed technical reportsare also presented. This is especially true in the case of the brown tide report, sincemany studies are still ongoing and much essential data has not yet been written up forpublication. Unpublished data is clearly identified as such, and cited as a personalcommunication from the scientist providing the data. I want to thank the many scientistswho shared unpublished data with us for this report. Many scientists are reluctant toshare unpublished data, but few conclusions could have been drawn on the brown tidebased on the paucity of published data. I have attempted to check with those providingdata to ensure that I have interpreted them correctly, but any errors in interpretation inthis report are only my own.The organization of the red tide report is different from that of the brown tide report,since there were relatively few published reports or unpublished data from theCCBNEP study area because of the rarity of these events. In addition to presentinginformation available on blooms in this area, relevant generalities are presented basedon the more frequent occurrences of these blooms in other locations, especially thewest coast of Florida.Dr. Edward J. BuskeyProject LeaderNovember 28, 1995Port Aransas, Texasix

TABLE OF CONTENTSPagePREFACE..............................................................................................................xiEXECUTIVE SUMMARY........................................................................................1BROWN TIDEI. INTRODUCTION TO THE TEXAS BROWN TIDE...........................................3II. HISTORICAL TRENDS OF TEXAS BROWN TIDES.......................................4Causative Species......................................................................................4Comparison to the New England Brown Tide.............................................5III. AVAILABLE DATA...........................................................................................7Environmental Conditions During and Immediately Precedingthe Brown Tide.................................................................................7Brown Tide Biomass.................................................................................20Spatial Distributions.................................................................................24Environmental Impact...............................................................................24IV. IDENTIFICATION OF PROBABLE CAUSES.............................................. 54V. IDENTIFICATION OF DATA AND INFORMATION GAPS...........................55VI. RECOMMENDATIONS FOR PRIORITY RESEARCH ANDMONITORING EFFORTS.............................................................................56Research..................................................................................................56Monitoring.................................................................................................57VII. LITERATURE CITED....................................................................................59RED TIDEVIII. INTRODUCTION TO HARMFUL RED TIDESIN TEXAS WATERS.....................................................................................66IX. HISTORICAL TRENDS OF TEXAS RED TIDE.............................................67Frequency................................................................................................67Duration....................................................................................................70Environmental Effects...............................................................................71Possible Causes.......................................................................................76X. AVAILABLE DATA.........................................................................................79Causative Species....................................................................................79Cell Concentrations/Other Biomass Estimates.........................................80Spatial and Temporal Bloom Distributions...............................................82Fish Kills...................................................................................................82Shellfish Beds...........................................................................................83Gulf of Mexico Circulation........................................................................84XI. POTENTIAL STATUS....................................................................................85x

TABLE OF CONTENTSPageXII. IDENTIFICATION OF DATA AND INFORMATION GAPS...........................87XIII. LITERATURE CITED...................................................................................89XIV. MATERIALS AND METHODS: UNPUBLISHED DATA...............................96XV. ANNOTATED BIBLIOGRAPHY....................................................................98XVI. ACKNOWLEDGMENTS............................................................................172xi

LIST OF TABLESBROWN TIDETablePage1. Comparison of Brown Tides.............................................................................5RED TIDE1. Shellfish Toxicity............................................................................................692. Aerial Survey of G. breve...............................................................................823. Fish Kills.........................................................................................................834. Shellfish Fishery Closures.............................................................................84xii

LIST OF FIGURESBROWN TIDEFigurePage1. Map of the Estuaries of the Texas Coast........................................................32. Map of Upper Laguna Madre and Baffin Bay..................................................83. Map of the Transects Taken in the Nueces Esturine System.........................84. Distribution of Brown Tide in Baffin Bay..........................................................95. Water Temperature (Laguna Madre and East Flats)....................................106. Water Temperature and Salinity (Laguna Madre and Baffin Bay)................117. Water Temperature (CPL Plant)...................................................................128. Secchi Depths (Nueces Estuary and Laguna Madre)...................................149. Secchi Depths (Laguna Madre and Baffin Bay)............................................1410. PAR (UTMSI, East Flats and Laguna Madre)..............................................1511. Dissolved Oxygen (CPL Plant).....................................................................1612. Ammonium Concentrations..........................................................................1713. Nitrate Concentrations.................................................................................1714. Nitrite Concentrations..................................................................................1815. Phosphate Concentrations...........................................................................1916. Silica Concentrations...................................................................................2017. Brown Tide Cell Counts (1990-1991)...........................................................2118. Brown Tide Cell Counts (1994-1995)...........................................................2219. Chlorophyll a Concentration (Transects).....................................................2220. Chlorophyll a Concentration (Stations A, B, C, and D)...............................2321. Primary Production for Laguna Madre.........................................................2422. Seagrass Shoot Density..............................................................................2623. Seagrass Shoot Biomass.............................................................................2724. Seagrass Root/Rhizome Biomass...............................................................2825. Ratio of Root/Rhizome to Shoot Biomass....................................................2926. Area of Seagrass Loss.................................................................................3027. Seagrass Biomass at Various Water Depths...............................................3128. Mean Seagrass Biomass.............................................................................3129. Mesozooplankton Abundance and Ctenophore Volumes............................3330. Acartia tonsa Prosome Lengths...................................................................3331. Acartia tonsa Egg Release Rates................................................................3432. Acartia tonsa Gut Pigment Concentration....................................................3433. Microzooplankton and Brown Tide Concentration.......................................3534. Microzooplankton grazing............................................................................3635. Growth Rate of Strombidinopsis...................................................................3736. Growth Rate of Fabrea salina......................................................................3837. Growth Rate of Euplotes sp.........................................................................38xiii

LIST OF FIGURESFigurePage38. Growth Rate of Noctiluca scintillans.............................................................3939. Growth Rate of Oxyhrris marina...................................................................3940. Growth rate of Brachionus plicatilus.............................................................4041. Survival of Acartia tonsa nauplii...................................................................4142. Survival of Acartia tonsa nauplii...................................................................4143. Egg Release Rate of Acartia tonsa..............................................................4244. Survival of Spotted Seatrout........................................................................4545. Survival of Red Drum...................................................................................4646. Feeding Rates of Spotted Seatrout..............................................................4647. Spotted Seatrout Larval Densities...............................................................4748. Spotted Seatrout Larval Densities...............................................................4849. Black Drum Larval Densities........................................................................4850. Bay Anchovy Larval Densities......................................................................4951. Macrobenthos Biomass................................................................................5052. Macrobenthos Abundance...........................................................................5053. Macrobenthos Diversity................................................................................5154. Game Fish Abundance................................................................................5255. Forage Fish Abundance...............................................................................53RED TIDE1. Gymnodinium breve Blooms........................................................................692. G. breve, Temperature, and Salinity............................................................803. G. breve Concentrations..............................................................................81xiv

Executive SummaryHarmful algal blooms appear to be increasingly common phenomena on aworldwide scale. These blooms can be considered "harmful" either because of theirpotential threat to human health through the consumption of contaminated seafood, asin the case of many toxic phytoplankton blooms, or through the changes in speciesabundances and distributions (often including species of commercial value), as in thecase of recent "brown tide" blooms. In the Corpus Christi Bay National Estuary Programarea, harmful algal blooms have been relatively rare; there appear to have been fewerthan a dozen documented red tide blooms over the entire Texas coast and only onedocumented (although extremely persistent) brown tide bloom. This may be due in partto blooms going undocumented, especially in the years prior to World War Two whenthe cause and effect relationship between toxic dinoflagellate blooms and fish andother marine life kills had not been established. In any event, harmful algal blooms arequite rare events and there is little evidence to suggest that they are increasing infrequency locally.Since January of 1990 the Laguna Madre has been experiencing a persistentbloom of small phytoplankton species generally referred to as the "brown tide". Thebrown tide began in January 1990 in Baffin Bay in an ecosystem that was alreadydisrupted by persistent high salinities that reduced the populations of planktonic andbenthic grazers. Two severe freezes in December of 1989 caused massive fish kills.The decomposition of these fish released a large nutrient pulse that was sufficient tofuel the initial bloom of brown tide. This nearly monospecific bloom has been caused byhigh densities of a small (4-5 µm diameter) algal species that was previouslyundescribed. The proposed name for this new species is Aureomonas lagunensis.Brown tide cell concentrations have ranged from 0.5 - 6 million cells/ml throughout thecourse of the bloom, and chlorophyll a concentrations have reached as high as 120µg/l with a mean of about 60 µg/l.The brown tide has reduced the clarity of waters of the Laguna Madre, shadingout sea grass beds and disrupting sports-fishing activities. The biomass of roots andrhizomes in the seagrass beds has decreased dramatically in the past two years of thebrown tide, indicating the seagrasses are using up their energetic reserves. It isestimated that over 9 square kilometers of seagrass beds had been lost by the end of1994. The nearly 200 square miles of seagrass beds in Laguna Madre represent thelargest undisturbed seagrass habitat on the Texas coast and these seagrass beds arean important nursery habitat for fish and an essential winter food resource to migratingwaterfowl.Zooplankton are the major consumers of phytoplankton in most marinesystems, and it is puzzling that zooplankton populations have not increased during thisalgal bloom. Mesozooplankton populations declined at the beginning of the bloom andhave remained low in areas impacted by the brown tide. The size of adult copepodswas lower and egg production rates were reduced in brown tide affected areas,1

indicating that brown tide was a poor food for these grazers. The brown tide has alsohad a dramatic affect on the benthic organisms of Laguna Madre; abundance, biomassand diversity of benthic fauna have all decreased.The extended brown tide bloom has had no apparent effect on populations ofadult fish and shellfish. This is in contrast to the apparent effects of brown tide on larvalfish populations. Both laboratory and field studies suggest that the brown tide may betoxic to newly hatched larval fish and that larval fish populations are reduced in areasseverely impacted by the brown tide.Perhaps the most important unanswered question is: why has the brown tidepersisted for so long? Part of the answer lies in long turnover times for waters inLaguna Madre and Baffin Bay. The lack of freshwater inflow and restricted exchangewith the Gulf of Mexico make it difficult to disperse an algal bloom once it becomesestablished. It also seems likely that this algal species may be competitively superior toother species in the harsh conditions of the Laguna Madre. It is also possible that thisspecies suppresses other algal species through allelopathic effects. It also appears tohave negative effects on populations of grazers that might help bring the bloom undercontrol.Apart from brown tides, red tides comprise the other common harmful algalbloom in Texas coastal waters. Two species of dinoflagellates are responsible for toxicred tides in Texas: Gymnodinium breve and Alexandrium monilata. The toxins of boththese dinoflagellate species can cause extensive mortality in fish and invertebratepopulations. Only G. breve blooms have been reported to cause human healthproblems through neurotoxic shellfish poisoning and respiratory irritation associatedtoxin containing aerosols. Red tides have been infrequent events on the Texas coastcompared to other areas of the Gulf of Mexico, such as the West coast of Florida.There have been only 4 documented G. breve and 7 A. monilata red tide blooms.Although occasionally the economic impacts of red tides are very severe, suchas in the 1986 red tide, they appear to have no long term affects on the ecosystem, asmay be the case with the brown tide. Fish populations, and tourism, soon return tonormally following the infrequent blooms, and no basic changes in marine policy seemwarrented to deal with them. Should toxic blooms in Texas increase in frequency and/orseverity, however, monitoring efforts should be considered to provide warning of bloominitiation and transport along the Texas coast.2

II. Historical trends of Texas brown tidesSince the algal species responsible for the Texas brown tide bloom has not beenpreviously described taxonomically, it is difficult to know with certainty if there havebeen previous occurrences of the Texas brown tide. Certainly algal blooms haveoccurred in the past in the Laguna Madre, as in any body of water. Long time residentsof south Texas recall periods of "brown water" in the Laguna Madre, but it is impossibleto know if the causative organism was the same one present in the current brown tide.Gunter (1945) cites reports of “reddish colored ‘bad’ water”, observed by pilots for theTexas Game, Fish and Oyster Commission, in Laguna Madre, and Simmions (1957)refers to red waters in the Laguna Madre as possibly being caused by: 1) dissolvediron 2) decaying vegetation 3) phytoplankton or 4) clay deposits. None of the previousreports seem to compare to the present bloom in either duration or severity.Examination of the stable carbon isotope ratios of organic carbon from sedimentcores collected in Baffin Bay suggest that the relative importance of seagrasses,macrophytic algae and phytoplankton may have shifted for decade long periods overthe last several thousand years (Parker and Scalan, personal communication). Thisalone is not proof that the brown tide organism dominated the Laguna Madre at anypoint in the past, but it does suggest that the relative importance of phytoplankton andseagrasses as primary producers in Baffin Bay have been different than the patternexisting in historical periods before the brown tide. To determine if the brown tide werethe organism responsible for phytoplankton dominance during these periods,biomarkers specific to the brown tide alga would be needed, and cores could beexamined for these compounds. This would require study of the diagenesis of browntide derived organic material.A. Causative speciesThe organism responsible for this bloom is a small (4-5 µm diameter) phytoplanktonspecies which has not yet been formally classified. Attempts to formally describe thisspecies have recently been completed and a species description has been submittedfor publication. The proposed name for this new species is Aureomonas lagunensis (H.DeYoe, personal communication). The Texas "brown tide" alga is devoid of obviousexternal diagnostic features when observed by optical microscopy, but examination ofultrastructure by transmission electron microscopy and of photosynthetic pigments byhigh performance liquid chromatography reveal that it is similar in morphology andpigments to Aureococcus anophagefferens (Sieburth et al., 1988; Stockwell et al.,1993) which has been responsible for recurrent blooms in Narragansett Bay and LongIsland bays since 1985 (Cosper et al., 1987). Recent molecular data indicate that bothspecies belong to a newly recognized class Pelagophyceae (Anderson et al., 1993),but the two species appear to differ enough from one another to warrant placing themin separate genera (DeYoe and Suttle, 1995).4

Organism:AureococcusanophageffernsTexas "browntide"Cell size (µm) 2 -3 4 - 5PigmentsType III Chrysophyte Type III ChrysophyteExternal Polysaccaride layer + +Cell wall None NoneViral inclusions + +DMS/cell 0.13pg 0.76pgPolyclonal antibodyfor Aureococcus + -Bloom CharacteristicsCell density (cells x 10 6 /ml) 0.5 - 2.6 0.5 - 5.0Chlorophyll a (µg/L) 18 20 - 140C 14 uptake (mgC/m 2 /h) 200 - 400 230 - 840Growth rates(doublings/day) 3 0.3 - 0.9Carbon:Chlorophyll ? 380:1Maximum duration 6 months 72 monthsReoccurence frequency 3 - 5 years ?Deleterious effects Yes* Yes*** Mussels, clams, scallops, eelgrass, zooplankton** Zooplankton, larval fish, seagrassTable 1. Comparison of the Texas "brown tide" organism with Aureococcusanophagefferens (adapted from Table in Stockwell et al., 1993).B. Comparison to the East Coast brown tideAlgal blooms of Aureococcus anophagefferens, a small (2 µm diameter)pelagiophyte, are also referred to as the East Coast brown tide. These blooms haveoccurred in several bays in the Northeastern United States including Narragansett Bay,RI, the Peconic-Gardiners Bay system, the south shore of Long Island, NY andBarnegat Bay, NJ (Lonsdale et al., in prep). These brown tides are restricted toshallow, vertically well-mixed waters, and have not occurred in Long Island Sound(Olsen, 1989; Nuzzi and Waters, 1989). The first bloom occurred in the summer of1985, lasting for up to six months in some locations. Widespread blooms recurred in1986 and 1987, and on a much more localized scale and of shorter duration in recentyears. During blooms of the East Coast brown tide, total phytoplankton biomass andprimary production rates are similar to those in non-bloom years (Cosper et al., 1989;Dennison et al., 1989). The demise of brown tide blooms is often associated withreplacement of the brown tide with other pico- and nanoplankton species present in lowconcentrations during the bloom (Sieburth and Johnson, 1989; Keller and Rice, 1989).There is no evidence that A. anophagefferens blooms are initiated from cysts, since low5

numbers of cells are found in affected waters throughout the year (Lonsdale et al., inprep).The exact causes of blooms of the East Coast brown tide remain unknown.Aureococcus has the ability to adapt to decreasing light levels as a bloom progressesand to maintain high growth efficiency under nutrient limiting conditions (Milligan,1992). A. anophagefferens is also tolerant of a wide range of temperature and salinityconditions. It grows best at higher temperatures found in East Coast waters in summer(20-25 o C) but can also grow at a slower rate at temperatures as low as 5 o C, allowingseed populations to be maintained through the winter (Cosper et al., 1989b).Physical factors that might contribute to the East Coast brown tide include longresidence times of bay waters and reduced rainfall (Cosper et al., 1989b). Thereappears to be a correlation between brown tide distribution and areas of elevatedsalinity. Growth rates of Aureococcus anophagefferens are faster at 30 ppt than 28 pptsalinity, and growth can be maintained at salinities between 22 and 35 ppt (Cosper etal., 1989b).The biomass of the East Coast brown tide cells was inversely related toconcentrations of dissolved inorganic nitrogen in both field measurements andmesocosm-based nutrient enrichment studies (Keller and Rice, 1989). Brown tideblooms were of shorter duration and lower biomass in nutrient enriched mesocosmsthan in controls. This suggests that the East Coast brown tide blooms are not causedby macronutrient loading, and in fact the persistence of East Coast brown tide bloomsmay be due in part to its ability to grow at nutrient concentrations previouslydemonstrated to limit the growth of diatoms (Keller and Rice, 1989). Aureococcus hasgreater ability for heterotrophic take up of dissolved organic compounds compared toother species of microalgae (Dzurica et al., 1989). Trace metals and their chelatorshave been shown to have an important effect on the growth rate of Aureococcus inculture. Both iron and selenium additions caused faster growth rates, and the use ofcitric acid as a chelator resulted in faster growth rates than with the chelators EDTA(ethylene-diminetetraacetic acid) or NTA (nitrilotriacetic acid) (Cosper et al., 1993).Increased use of citric acid instead of phosphates in some detergents and increasedmunicipal use of deep groundwater with higher iron concentrations may havecontributed to the brown tide blooms (Cosper et al., 1993). No evidence of allelopathiceffects of chemicals released by the brown tide on the growth of other phytoplanktonspecies has been found (Cosper et al., 1989b).There is less information available on the factors leading to the termination ofblooms of Aureococcus anophagefferens. Little is known about the role ofmicrozooplankton grazing in bloom dynamics of the East Coast brown tide (Lonsdale etal., in prep). Sieburth et al. (1988) noted the occurrence of viral particles within A.anophagefferens cells during the 1985 bloom in Narragansett Bay, but the role ofviruses in the bloom dynamics of this organism remains unknown.6

Perhaps the most important impact of the East Coast brown tide has been itsdetrimental effects on commercially important species of benthic macrofauna, such asscallops and mussels, and on eelgrass beds. Populations of the mussel Mytilus edulisin Narragansett Bay experienced mass mortalities of 30 to 100% (Tracey, 1988). InPeconic Bay, New York, adult bay scallops Argopecten irradians suffered heavymortality (Wenczel, 1987) and losses in mussel weight reducing harvest (Bricelj et al.,1987) resulting in economic losses to the scallop fishery estimated at two million dollarsper year (Kahn and Rockel, 1988). No data has been collected on the effects of thebrown tide on other benthic invertebrates (Lonsdale et al., in prep).Early outbreaks of the East Coast brown tide also caused severe reduction inlight penetration during the main growing season in shallow seagrass beds, resulting ina significant reduction in leaf biomass and confinement of eelgrass populations toshallow water (Dennison et al., 1989). Eelgrass provides an important nursery habitatfor many marine species, including bay scallops, and the losses of seagrass habitatmay have contributed to the lower populations of scallops during brown tide outbreaks.III. Available dataA. Environmental conditions during and immediately preceding the brown tide1. Initiation of the bloomScientists at the Marine Science Institute of the University of Texas (UTMSI)were carrying out a multi-investigator study of the Laguna Madre during the time whenthe brown tide began. Most experimental work was performed at two stations overseagrass beds in the upper Laguna Madre designated stations A and B, and at twostations in Baffin Bay over muddy bottoms, designated stations C and D (Figure 2).This study also included a monthly hydrographic survey at up to 44 stations in theupper Laguna Madre where basic hydrographic data were collected including seawatertemperature, salinity, pH and oxygen concentration. Seawater samples were alsocollected for chemical analysis of nutrient concentrations, including nitrate, nitrite,ammonium, phosphate and silicate. Water was also collected for determination ofphytoplankton biomass estimated as chlorophyll a concentration. At a subset ofstations in the upper reaches of Baffin Bay, whole water samples were preserved inLugol's iodine preservative for possible future analysis of the effects of high salinitieson phytoplankton and microzooplankton species composition. Secchi depth andchlorophyll a readings were taken from various transects in the Nueces and CorpusChristi Bays prior to the onset of the brown tide by Texas Water Development Board(Figure 3). UTMSI scientists first became aware of the presence of the brown tide inJune of 1990, when brown waters were encountered throughout upper Laguna Madrewith extremely high chlorophyll concentrations (Figure 4). The unusual nature of thebrown tide bloom was not realized for several months. Previously unexaminedpreserved whole water samples from Baffin Bay were then examined for the presence7

This hypothesis was rejected when a brown tide bloom developed in Copano Bay in thesummer of 1991 in waters of

Temperature and Salinity for Laguna Madre70Temp (0-35 0 C) and Salinity (30-70 ppt)605040302010Sta. A(Temp)Sta. A(Sal'n)Sta. B(Temp)Sta. B(Sal'n)Sta. C(Temp)Sta. C(Sal'n)Sta. D(Temp)Sta. D(Sal'n)0Mar'89May'89July'89Sept'89Nov'89Jan'90Mar'90May'90July'90Sept'90Nov'90Jan'91Mar'91May'91July'91DateFigure 6. Water temperature and salinity at four locations in the upper Laguna Madreand Baffin Bay from March 1989 until August 1991. Data from Dr. E.J. Buskey,University of Texas Marine Science Institute.Water temperatures in the Laguna Madre can vary by 5 o C or more over shortperiods of time due to changes in cloud cover and wind conditions and the shallowbody of water involved. In the late fall, winter and early spring, the passage of coldfronts can cause even wider fluctuations in the temperature of the Laguna Madre over ashort period of time. Daily temperatures at the intake to the Central Power and Lightelectrical generating station on the shore of Laguna Madre during part of 1993 and1994 are shown in Figure 7.11

Plot of Temperatures measured at CPL intake '93-'94353025Temp ( 0 C)201510506/30/93 8/19/93 10/8/93 11/27/93 1/16/94 3/7/94 4/26/94 6/15/94 8/4/94 9/23/94 11/12/94 1/1/95DateFigure 7. Water temperatures at the intake for the Central Power and Light electricalgenerating plant in Corpus Christi. Water for cooling the power plant is withdrawn fromthe Laguna Madre and returned to Oso Bay. Data provided by the GCCA/CPL redfishhatchery.3. Residence Time of Water in BaysWater in coastal bays is in a constant state of flux. Fresh water is added throughrainfall, groundwater and rivers. Freshwater can leave coastal bays directly throughevaporation or indirectly as less saline waters flow out of the bays into the Gulf ofMexico. Waters from the Gulf of Mexico are also mixed into coastal bays by way of tidalexchange. The residence times of waters in Texas coastal bays depends mainly on theamount of freshwater inflow and the tidal exchange from surrounding areas. Shormann(1992) estimated the residence times of three Texas bays in the CCBNEP area, BaffinBay, Nueces Bay and Copano Bay, in order to look into its possible effects on thepersistence of brown tide blooms in these three areas. He used the equationsdescribed in Armstrong (1982) to estimate residence time based on freshwater inflowand salinity data, and the equations described in Smith (1985) to estimate the effects oftidal flushing.Shormann (1992) assumed that tidal flushing of Baffin Bay was negligiblebecause of the bay's isolation from any passes to the Gulf of Mexico. Based onfreshwater inflow data, a residence time of approximately 12.5 years was calculated. A12

second residence time was calculated taking into account the losses of water throughevaporation. Based on these data, a residence time of approximately one year wascalculated. However, it should be noted that this turnover time is based on waterleaving by evaporation, and planktonic organisms such as the brown tide wouldactually be concentrated in Baffin Bay rather than be diluted out. In reality, asevaporation occurs, water becomes more dense, so some of this dense water probablyflows out along the bottom of Baffin Bay and is replaced by less saline water from theupper Laguna Madre. However, the upper Laguna Madre is also heavily impacted bythe brown tide, and this exchange does little to dilute the brown tide.Shormann (1992) also calculated residence times for Nueces Bay of 25 days,and for Copano Bay of 214 days. These calculated residence times correspondapproximately to the relative persistence of episodes of brown tide in each of thesebays. The brown tide spread into Nueces Bay on at least one occasion in August 1992,but it only persisted for a few weeks. Examination of brown tide cells using transmissionelectron microscopy showed the presence of what appeared to be viral particles withincells, suggesting that termination of this short lived bloom may have been enhanced bypathogens (Stockwell, pers. comm.).The brown tide has also spread into Copano Bay,and has persisted there for periods of several months. In Baffin Bay, with a calculatedresidence time of a year or longer, the brown tide has persisted for over five years, andhas not abated since the bloom began.4. Light transmissionLight transmission through seawater is an important factor, along withtemperature and nutrient availability, determining the amount of primary production thatcan occur in a body of water. A brown tide event, typically with a cell concentration ofone million cells per ml of seawater, can severely reduce the penetration of lightthrough seawater. Light transmission through seawater is largely affected by thepresence of dissolved and suspended materials that both absorb and scatter light. Asphotosynthetic organisms, brown tide algal cells absorb light in order tophotosynthesize; as small particles suspended in the water column they also scatterlarge amounts of light. One of the simplest ways to quantify the transparency of naturalwaters is to measure the greatest depth below the surface at which a small white disk,called a Secchi disk, can still be seen by an observer above the water's surface. Theyearly average Secchi depth, the depth at which the disk can no longer be seen, forseveral transects along Nueces Bay, Corpus Christi Bay and the upper Laguna Madre,prior to the brown tide, is shown in Figure 8. There is a general increase in watertransparency from average Secchi depths of ca. 50 cm in Nueces Bay to 80 - 100 cmas you approach the Laguna Madre. A somewhat incomplete record of Secchi depthsat four stations in the Laguna Madre and Baffin Bay is shown in Figure 9. Before thebrown tide began, Secchi depths were as great as 1.5m (the depth of the water column)in the Laguna Madre. During the most severe parts of the brown tide, Secchi depthswere often less than 0.5 m. Water clarity often improves for short periods of time in the13

winter, when cold fronts displace the brown tide laden water with relatively clear waterfrom Corpus Christi Bay.Sechi depths for Nueces estuary and upper Laguna Madre1.80Depth (m)1.601.401.201.000.800.600.400.200.0085 86 87 88 89Year475364122127142147Figure 8. Yearly average Secchi depth data at various transects throughout Nuecesestuary (47 & 53) and the upper Laguna Madre (64-147). Data provided by the TexasWater Development Board.Secchi depths for Stations A, B, C, D1.61.41.2Depth (m)10.80.6STA ASTA BSTA CSTA D0.40.204/2/89 7/11/89 10/19/89 1/27/90 5/7/90 8/15/90 11/23/90 3/3/91 6/11/91 9/19/91 12/28/91DateFigure 9. Monthly Secchi depth measurements taken at four stations in Laguna Madreand Baffin Bay. Data provided by Dr. Terry Whitledge, University of Texas MarineScience Institute. Station locations are shown in Fig. 2.14

In spite of the warm temperatures and high organic loads in the water columnduring the brown tide event, there have been no major fish kills reported in theCCBNEP that can be traced to anoxic events. This is due primarily to the shallow, wellmixed water column, which does not allow water near the bottom to be isolated from thesurface for long periods of time. Dissolved oxygen levels typically remain above 2 mg/l,even during warm summer months with high brown tide concentrations (Figure 11).D.O. levels at the CPL intake '93-'94109876D.O. (mg/L)5432106/30/93 8/19/93 10/8/93 11/27/93 1/16/94 3/7/94 4/26/94 6/15/94 8/4/94 9/23/94 11/12/94 1/1/95DateFigure 11. Morning dissolved oxygen levels measured in seawater at the intake to theCentral Power and Light electrical generating station. Samples taken betwee 4:00 and5:00 AM. Data provided by GCCA/CPL redfish hatchery.6. NutrientsPrior to the bloom of the Texas brown tide alga, concentrations of dissolvedinorganic nitrogen (DIN) in Baffin Bay and Upper Laguna Madre increased from

NH 4 concentrations for Laguna Madre3025uM201510STA ASTA BSTA CSTA D5003/8906/8908/8910/8912/8902/9004/9006/9008/9010/9012/9002/9104/9106/9108/9110/9112/91DateFigure 12. Ammonium concentrations in the upper Laguna Madre and Baffin Bay, fromMarch 1989 through December 1991. The 1990 winter / spring maxima was ascribedto the freeze induced fish and invertebrate die off. Unpublished data from Dr. T.E.Whitledge, University of Texas Marine Science Institute.NO 3 concentrations in Laguna Madre1210uM8642003/8906/8908/8910/8912/8902/9004/9006/9008/9010/9012/9002/9104/9106/9108/9110/9112/91STA ASTA BSTA CSTA DDateFigure 13. Nitrate concentrations in the upper Laguna Madre and Baffin Bay, fromMarch 1989 through December 1991. Unpublished data from Dr. T.E. Whitledge,University of Texas Marine Science Institute.17

NO 2 concentrations for Laguna Madre2.52.0uM1.51.0STA ASTA BSTA CSTA D0.50.003/8906/8908/8910/8912/8902/9004/9006/9008/9010/9012/9002/9104/9106/9108/9110/9112/91DateFigure 14. Nitrite concentrations in the upper Laguna Madre and Baffin Bay, fromMarch 1989 through December 1991. Unpublished data from Dr. T.E. Whitledge.,University of Texas Marine Science Institute.Of this DIN increase, 60-95 % was in the form of NH 4+(Stockwell et al., 1993,Whitledge 1993, unpublished data). This large influx of ammonium was beneficial tothe Texas brown tide alga since, unlike most other algae, it is unable to use NO 3 - as anitrogen source. Aureococcus anophagefferens, the algal species associated with thenortheastern brown tides, is able to take up and reduce NO 3 - , NO 2 - , and NH 4 + . Evidencesuggests that the Texas brown tide species is able to take up all three inorganic formsof nitrogen, but is unable to reduce NO 3 - due to a lack of a functional nitrate reductase(DeYoe and Suttle, 1994).The large input of nitrogen is most often ascribed to two severe winter freezeswhich induced large fish kills and a salinity / temperature induced invertebrate die off(Stockwell et al., 1993, Whitledge, 1993, DeYoe and Suttle, 1994). An estimated965,000 fish died in Baffin Bay and Upper Laguna Madre. This fish kill could havereleased approximately 2.01 x 10 7 g of N into the system (DeYoe and Suttle, 1994). Inthe year prior to the bloom, the invertebrate population decreased by over 90%releasing an estimated 0.48 g of N m -2 into Baffin Bay and 6.29 g of N m -2 into upperLaguna Madre (Montagna, personal communication). DeYoe and Suttle (1994)estimate that this increase in N would be sufficient to produce 6x10 12 cells m -3 , anamount larger than was actually observed during the bloom.This pulse of ammonium has been ascribed as a factor leading to the initiation ofthe Texas brown tide algal bloom. However, high concentrations of DIN might not benecessary to maintain the bloom. A study of the brown tide organism, Aureococcusanophagefferens, in Narragansett Bay has shown that the northeastern brown tidebloom was maintained during periods of extremely low DIN levels (< 1.0 µM) (Keller18

and Rice, 1989). Since Aureococcus is a picoplankton (cell size 2-3 µm), its highsurface area to volume ratio could allow it to take up a greater portion of the availablenutrients than the other, larger, phytoplankton (Joint, 1986). Keller and Rice (1989)found that the brown tide population diminished and other phytoplankton populationsrecovered when nutrient levels increased in bloom waters. In Texas, after the initialpre-bloom pulse, inorganic nutrient levels remained low for ca. 12 months (DIN< 3µMand PO 4 - ca. 1µM). However, the Texas brown tide bloom has successfully persistedthrough several periods of nutrient enrichment in Laguna Madre (Whitledge, 1993 andunpubl. data, Dunton, unpubl. data).Phosphorus and silica are rarely thought to be limiting in a coastal environment(Boynton et al., 1982); as a result almost no studies have been done on the effects ofthese nutrients on the Texas brown tide alga. A small increase of PO 4 - was observedprior to the start of the brown tide bloom (Figure 15). Phosphate levels increased fromca. 1µM to 3 µM (Whitledge, unpubl. data). It is unlikely that this pulse of phosphatewould have much effect since, phosphorous is limiting to the Texas brown tide algaonly when an unnaturally large (ca. 100µM) pulse of nitrogen is added to the system(Whitledge, pers. comm.). No studies have been done on the effect of silica levels onthe Texas brown tide alga. While the brown tide organism does not have aphysiological requirement for silica, it is conceivable that sufficient levels could allowdiatoms to compete with the alga. A drop in silica levels prior to the bloom (Figure 16)helps support this idea.PO4 concentration for Laguna Madre76uM54321003/8906/8908/8910/8912/8902/9004/9006/9008/9010/9012/9002/9104/9106/9108/9110/9112/91STA ASTA BSTA CSTA DDateFigure 15. Phosphate concentrations in the upper Laguna Madre and Baffin Bay, fromMarch 1989 through December 1991. Unpublished data from Dr. T.E. Whitledge,University of Texas Marine Science Institute.19

SiO 4 concentrations for Laguna Madre140120uM1008060STA ASTA BSTA CSTA D4020003/8906/8908/8910/8912/8902/9004/9006/9008/9010/9012/9002/9104/9106/9108/9110/9112/91DateFigure 16. Silica concentrations in the upper Laguna Madre and Baffin Bay from March1989 through December 1991. Unpublished data from Dr. T.E. Whitledge, University ofTexas Marine Science Institute.B. Brown tide biomassOne way to estimate the severity of the brown tide bloom at any specific place ortime is to collect a water sample and count the number of brown tide cells present in avolume of water. Since most marine phytoplankton populations are quite diverse, it canbe a very difficult and time consuming task to try to identify all the species ofphytoplankton present in a water sample and determine their abundance throughquantitative microscopic analysis of samples. A more common practice is toconcentrate plankton samples on filters and measure the concentration ofphotosynthetic pigments characteristic of all phytoplankton, such as chlorophyll a. Theamount of chlorophyll a present in a volume of water is then assumed to beproportional to the total biomass of phytoplankton present. The pigment composition ofphytoplankton varies both with species and environmental conditions, so the ratio ofchlorophyll a to total biomass can vary considerably from sample to sample. In the caseof a nearly monospecific phytoplankton bloom such as the brown tide, most of thepigment is produced by a single species, so some of the variability is reduced andchlorophyll concentrations can be quite useful for comparing the concentrations ofbrown tide within different areas of the bloom and at different times of the year.However, since all phytoplankton species contain chlorophyll a, this parameterprovides no information about the proportion of the phytoplankton biomass contributedby the brown tide compared to other species. It can provide no indication of whenbrown tide is present or absent in the water.20

It is also possible to enumerate the concentration of brown tide cellsmicroscopically. The cells of the brown tide alga are small (4-5 µm in diameter) andvery abundant in areas obviously affected by the brown tide. However, cells of thebrown tide alga are morphologically indistinct, and there are no external characteristicsthat can be used for positive microscopic identification.1. Cell countsIn the spring of 1990 the first "bloom" level abundances of the brown tide algawere observed in Laguna Madre. Prior to this time, the brown tide alga had not beenobserved in this area. Due to its indistinct appearance, this does not mean it was notpresent in low numbers and simply not recognized in phytoplankton samples. As figure17 shows, brown tide levels quickly increased from their initial observed levels of ca.500,000 cells/ml in June 1990 to over 2 x 10 6 cells/ml in July 1990. Populationabundances decreased from this summer high during the winter months but remainedat bloom levels (ca. 1 x10 6 cells/ml). Cell counts once again increased during thesummer months. Unlike A. anophagefferens, the Texas brown tide is able to maintainhigh abundance levels through the winter months. Thus, instead of a bloom which lastsfor several months, Texas has experienced a bloom of brown tide alga which has lastedover 5 years and still has an abundance over 500,000 cells/ml (Figure 18).Brown Tide Counts for Laguna Madre400000035000003000000Cells/ml250000020000001500000STA ASTA BSTA CSTA D10000005000000Oct-89 Jan-90 May-90 Aug-90 Nov-90 Mar-91 Jun-91 Sep-91DateFigure 17. Brown tide cell counts for 4 locations in upper Laguna Madre and Baffin Bayfrom December 1990 through August 1991. Buskey and Stockwell (1993) andunpublished data of Dr. E.J. Buskey, The University of Texas Marine Science Institute.21

Brown Tide Counts Upper Laguna Madre5Cells/ml x10^64.543.532.521.510.5011/12/94 1/1/95 2/20/95 4/11/95 5/31/95 7/20/95DateMouth Corpus ChristiBayStation AStation CLaguna Madre Southof Baffin BayFigure 18. Brown tide counts for 4 locations in upper Laguna Madre and Baffin Bayfrom November 1994 through June 1995. Unpublished data of Dr. Roy Lehman, TexasA&M University - Corpus Christi, Center for Coastal Studies.2. Chlorophyll aFrom 1983 through 1989, prior to the initiation of the brown tide bloom, thechlorophyll a maxima never exceeded 17 µg/L (Figure 19). After the bloom, chlorophylla concentrations, during peaks, have exceeded 40µg/L (Figure 20).CHlorophyll a Concentrations for Nueces Bay and Laguna Madre1816Chl a (ug / L)1412108647536412212714214718342083 84 85 86 87 88 89YearFigure 19. Yearly average chlorophyll a concentrations averaged along cross baytransects running from Nueces Bay through the upper Laguna Madre. (See Figure 3 forthe location of these transects.) Data provided by the Texas Water DevelopmentBoard.22

Chlorophyll Data From STEPS60A5040µg Chla /L30STA ASTA C20100Jan-89 Jun-89 Nov-89 Apr-90 Sep-90 Feb-91 Jul-91 Dec-91 May-92 Sep-92 Feb-93 Jul-93DateChl concentrations for Laguna Madre7060Bµg/ml5040302010003/8906/8908/8910/8912/8902/9004/9006/9008/9010/9012/9002/9104/9106/9108/9110/9112/91STA ASTA BSTA CSTA DDateFigure 20. (A) Chlorophyll a data from stations A and C in the upper Laguna Madre andBaffin Bay, respectively, from March 1989 through February 1993. Unpublished datafrom Dr. Dean Stockwell, University of Texas Marine Science Institute.(B) Surface chlorophyll a concentrations (µg/l) from four stations in the upper LagunaMadre from March 1989 until December 1991. Unpublished data of Dr. TerryWhitledge, University of Texas Marine Science Institute.Primary production (gC m -2 d -1 ) before the brown tide averaged 1.2 gC m -2 d -1 ,while after the brown tide the average increased to 2.0 gC m -2 d -1 (Figure 21). Both23

D. Environmental impact1. SeagrassesOne of the greatest potential impacts of the brown tide on the Laguna Madreecosystem is the loss of seagrass due to reduced light penetration. Reductions in waterclarity are thought to have been responsible for large scale losses in seagrass habitatin the past (Kenworthy and Haunert, 1991), and the depth limit of seagrass meadows isoften assumed to be constrained by the depth of light penetration required forphotosynthesis (Dennison, 1987; Duarte, 1991). The brown tide has caused areduction in light penetration which increases with depth of the water column, so thegreatest impact of the brown tide should be on seagrasses at the greatest depths.A study by Dr. Ken Dunton at the University of Texas Marine Science Institutecompared seagrass growth characteristics at sites in the Laguna Madre near station Awhich has been heavily impacted by the brown tide and a site in the East Flats ofCorpus Christi Bay that has been generally free of the brown tide. Seagrass shootdensity can be quite variable at both sites, particularly during the period from 1989 untilthe summer of 1992 (Figure 22). Following the summer of 1992, shoot density at thesite in the East Flats of Corpus Christi Bay remained largely unchanged, whereas shootdensity showed a steady decline during the same period at the site in Laguna Madre,decreasing from 8-10 thousand shoots per square meter in the summer of 1992 to lessthan 4,000 shoots per square meter by the end of 1994 (Figure 22). Seagrass arealshoot biomass, measured in grams dry weight per square meter also showsconsiderable variability, but a seasonal pattern of high shoot biomass in late summer isobserved in each year except 1991 at the East Flats site, whereas summer biomasspeaks appear to be dampened out after 1991 at the Laguna Madre site (Figure 23).However, above ground shoot density and biomass measures may not necessarily bethe best indicators of stress induced by reduced light intensities because seagrassesstore reserve energy in their rhizomes, and can use these reserves to produce aboveground biomass during periods of reduced light. The biomass of roots and rhizomeshas been declining steadily since 1992 at the Laguna Madre site, compared to a morevariable pattern at the East Flats site (Figure 25). The ratio of root and rhizomebiomass to shoot biomass dropped from a high of 16 in Laguna Madre before thebrown tide began, and then fell to a value of 2 to 4 during the brown tide bloom, whereit has stabilized. The range of ratios observed at the East Flats site, unlike LagunaMadre, varied with a relatively consistent seasonal pattern from 1 to 3 (Figure 25).25

Station A1400012000Density (Shoots m -2 )10000800060004000200009/88 4/89 10/89 5/90 11/90 6/91 12/91 7/92 1/93 8/93 3/94 9/94 4/95DateEast Flats1400012000Density (Shoots m -2 )100008000600040002000010/89 5/90 11/90 6/91 12/91 7/92 1/93 8/93 3/94 9/94 4/95DateFigure 22. Seagrass shoot density (shoots/m 2 ) at a location in upper Laguna Madre(top) and a location in East Flats of Corpus Christi Bay (bottom). Data from Dr. KenDunton, University of Texas Marine Science Institute.26

Station A300Areal Shoot Biomass (gdw m-2)2502001501005001/89 7/89 2/90 8/90 3/91 9/91 4/92 11/92 5/93 12/93 6/94DateEast Flats300Areal Shoot Biomass (gdw m-2)25020015010050010/89 5/90 11/90 6/91 12/91 7/92 1/93 8/93 3/94 9/94 4/95DateFigure 23. Seagrass areal shoot biomass (gdw/m 2 ) at a location in upper Laguna Madre(top) and a location in East Flats of Corpus Christi Bay (bottom). Data from Dr. KenDunton, University of Texas Marine Science Institute.27

Station A600Root/Rhizome Biomass (gdw m -2 )50040030020010009/88 4/89 10/89 5/90 11/90 6/91 12/91 7/92 1/93 8/93 3/94 9/94 4/95DateEast Flats600Root/Rhizome Biomass (gdw m -2 )500400300200100010/89 5/90 11/90 6/91 12/91 7/92 1/93 8/93 3/94 9/94 4/95DateFigure 24. Seagrass root/rhizome biomass (gdw/m 2 ) at a location in upper LagunaMadre (top) and a location in East Flats of Corpus Christi Bay (bottom). Data from Dr.Ken Dunton, University of Texas Marine Science Institute.28

Station A2018Root/Rhizome:Shoot Ratio16141210864209/88 4/89 10/89 5/90 11/90 6/91 12/91 7/92 1/93 8/93 3/94 9/94 4/95DateEast Flats2018Root/Rhizome:Shoot Ratio161412108642010/89 5/90 11/90 6/91 12/91 7/92 1/93 8/93 3/94 9/94 4/95DateFigure 25. Ratio of root/rhizome biomass to shoot biomass at a location in upperLaguna Madre (top) and a location in East Flats of Corpus Christi Bay (bottom). Datafrom Dr. Ken Dunton, University of Texas Marine Science Institute.Dr. Christopher P. Onuf (submitted), reports on changes in seagrass distributionand biomass due to light attenuation of the Texas brown tide. Comparisons of pre- andpost-brown tide studies were made to give an estimate on the amount of sea grasses29

It is thought that light attenuation due to the brown tide is responsible for theseagrass losses. Underwater photosynthetically available radiation (PAR) wasmeasured at 1 min intervals at three locations (Figure 26). Secchi depths were taken atapproximately monthly intervals from March 1992 to November 1994 at stations 100mfrom the eastern and western shores of the Laguna and at the midpoint on east-westtransects at 27 o 20’, 22’, 26’ 30’, 38’ and 40’. These Secchi depths were related to PARby determining light vs. depth profiles and computing attenuation coefficients todetermine the proportion of surface light reaching the bottom. Light attenuationincreases from north to south which is consistent with the higher biomass seen at thegreatest depths in the northern portion of the study prior to 1993 (Figure 28). Thecompensation point for Halodule has been estimated at 12 - 20% of surface irradiation(Kenworthty, et al. 1991, Onuf, 1991). Using an average compensation point of 15%surface irradiance, Onuf predicts that 23% of the study area is too deep to supportHalodule while the brown tide persists. Prior to the brown tide only 6% of LagunaMadre was too deep .Although 17% of the 1988 meadow has continually received light below thecompensation level, only 6% of the meadow has been lost. Onuf (1995) proposes thatHalodule is “able to survive periods of inadequate light by reducing the number ofshoots it maintains and supporting the reduced demands by metabolizing thecarbohydrate reserves stored in below ground tissues.” The reduction in biomass priorto loss in distribution supports this hypothesis. As the brown tide persists the coverageshould continue to decrease (as it did from 1993 to 1994). Since seagrasses preventresuspension of sediment, the loss of the seagrass could increase the light attenuationof suspended particles, leading to even greater seagrass losses. These losses couldhave a major effect on species, such as the Redhead ducks (Anthya americana) whichdepend on Halodule wrightii for food and shelter.2. Planktonic GrazersMesozooplankton populations, dominated by the copepod Acartia tonsa, weregenerally abundant before the onset of the brown tide, although there was considerablespatial and temporal variability in population density (Figure 29). In Baffin Bay,mesozooplankton densities ranged from 1,500 to 23,500 organisms per cubic meterbefore the onset of the brown tide. After the beginning of the brown tide,mesozooplankton densities remained below 8,000 per cubic meter through July 1991.The ctenophore Mnemiopsis mccradyi was abundant in Baffin Bay in March and April1990, just prior to the spread of the brown tide.The size of adult female Acartia tonsa, measured as prosome length, is usually afunction of the temperature and salinity of the waters the organisms grow in. Highertemperatures and higher salinities result in smaller copepods. In Baffin Bay, whereconditions were extremely hypersaline, both temperature and salinity affected the sizeof A. tonsa. In Laguna Madre, where conditions were less hypersaline, temperature hadthe most important influence on the size of A. tonsa before the brown tide, with32

copepods reaching their maximum size in the cool winter months (ca. 0.75 mmprosome length) and their minimum size in hot summer months (ca. 0.55 mm prosomelength) (Figure 30). During the brown tide, A. tonsa remained small throughout thecooler winter months (0.6 mm prosome length).Mesozooplankton(x1000 m-3)504540353025201510504035302520151050Mar-89Jun-89Sep-89Dec-89Mar-90Ctenophore Volume(ml/m3)Jun-90Oct-90Jan-91Apr-91Jul-91DateMesozooplanktonCtenophoresFigure 29. Mesozooplankton abundance and ctenophore displacement volume in BaffinBay before and during the brown tide. Adapted from Buskey and Stockwell (1993).350.930Temperature ( o C)2520151050.80.70.6Prosome Length (mm)00.5Sep-88 Apr-89 Oct-89 May-90 Nov-90 Jun-91 Dec-91Month (1989 -1991)Surface TempProsome lengthFigure 30. Prosome lengths of adult female Acartia tonsa at station A in Laguna Madrebefore and during the brown tide bloom, and temperature data from the same station.Before the brown tide, the size of copepods was a function mainly of watertemperature; after the bloom copepods remained small throughout the year, indicatingpoor nutrition. Adapted from Buskey and Stockwell (1993).33

Egg release rates by adult female Acartia tonsa ranged from 20-60 eggs perfemale per day in Baffin Bay before the brown tide began (Figure 31). After the browntide began, the egg release rate was consistently below 5 eggs per female per day.706050403020100Brown Tide BeganMar-89Jul-89Nov-89Eggs/Female/DayMar-90Jul-90Nov-90Mar-91Month (1989-1991)Figure 31. Egg release rates of adult female Acartia tonsa before and during the browntide, based on 48 hour field incubations. Adapted from Buskey and Stockwell (1993).Gut pigment contents can be used to estimate grazing rates ofmesozooplankton. Before the brown tide began, gut pigment contents for adult femaleAcartia tonsa ranged from 2 -18 ng pigment per copepod. Gut pigment contents were atthe detection limit of our analytical technique (< 1 ng chl a /copepod) following thebrown tide, even though surface water chlorophyll concentrations were 2-10x higher(Figure 32).Gut Pigments (ng/copepod)181614121086420Before Brown tideAfter Brown Tide0 20 40 60 80Surface Chl a (ug/l)Figure 32. Daytime gut pigment (chlorophyll a plus phaeopigments) concentrations foradult female Acartia tonsa compared to phytoplankton biomass (chlorophyll a) beforeand during the brown tide. High gut pigment concentrations indicate active feeding onphytoplankton. Adapted from Buskey and Stockwell (1993).34

The observed changes in zooplankton populations could have been due to thenutritional inadequacy of the brown tide alga to support zooplankton growth andreproduction, or there may be a substance produced by the algae that interferes withzooplankton feeding. Lower egg laying rates were reported for Acartia tonsa fromNarragansett Bay, RI, when fed phytoplankton collected in the field during anAureococcus bloom (Durbin and Durbin, 1989). Increases in body size, condition factor(a ratio of weight to a unit of length), egg laying rate and gut pigments were reportedwhen field collected Acartia tonsa were fed cultured algae in their preferred size rangeduring laboratory experiments.Microzooplankton populations consisting mainly of ciliates, copepod nauplii androtifers, were generally abundant before the brown tide began, with populationsgenerally ranging between 20-200 per ml. After the brown tide began, themicrozooplankton populations remained below 30 per ml (Figure 33). Microzooplanktongrazed ca. 85-98% of the phytoplankton standing stock per day before the brown tide,but < 3% per day during the brown tide (Figure 34). The inability of microzooplanktongrazers to control populations of the brown tide alga may result from the production ofsubstances that inhibit the grazing and/or growth of microzooplankton. Anotherpossible explanation might be that the mesozooplankton exerted additional predationpressure on microzooplankton populations during the brown tide, due to the lack ofphytoplankton food in their preferred size range.1202.5Microzooplankton/ml10080604020021.510.50Dec-88Apr-89Jul-89Oct-89Jan-90May-90Aug-90Nov-90Mar-91Brown Tide (cells/ml x 10 6 )Jun-91Sep-91Month (1989-1991)MicrozooplanktonBrown TideFigure 33. Microzooplankton abundance and brown tide cell concentrations at StationC in Baffin Bay before and during the brown tide. Adapted from Buskey and Stockwell(1993).35

Chl a (mg/m 3 )4035302520151050Brown Tide BeganMar-89May-89Jul-89Sep-89Sep-89Jan-90Mar-90May-90Jul-90Sep-90Nov-90Month (1989-1990)Initial Standing Crop Amount GrazedFigure 34. Microzooplankton grazing of phytoplankton standing stock before and duringthe brown tide, based on field incubation using the dilution technique of Landry andHassett (1982). Adapted from Buskey and Stockwell (1993)Laboratory StudiesLaboratory studies of the effects of the Texas brown tide alga on zooplanktonhave been carried out by Dr. Edward J. Buskey of the University of Texas MarineScience Institute. The ciliate Strombidinopsis sp. showed a typical numerical responseof increasing specific growth rate with increases in food concentration until maximumgrowth rate is reached, when the food offered was Pyrenomonas salina. The thresholdconcentration for growth appeared to be ca. 0.1 mg C l -1 , and a maximum specificgrowth rate of 0.96 d -1 was achieved at a food concentration of 1 mg C l -1 (Figure 35).When this same species was fed the Texas brown tide alga, a different numericalresponse was found. All specific growth rates were negative, indicating mortality ratherthan growth on this food source. Since specific growth rates became more negative asfood concentrations of brown tide increase (i.e. death rate increased), it appears thatthe brown tide is toxic to this species.36

Specific Growth Rate (day -1 )1.510.50-0.5-1-1.50 1 2 3 4 5Phytoplankton Concentration (mg C/l)Fed Pyrenomonas Fed Brown TideFigure 35. Specific growth rate (d -1 ) of the ciliate Strombidinopsis sp. on variousconcentrations of the Texas brown tide alga and on Pyrenomonas salina. Error barsrepresent the standard error of the slope of line for the natural logarithm of the numberof cells regressed against time, used to determine specific growth rates. Adapted fromBuskey and Hyatt (1995).In contrast, the ciliates Fabrea salina and Euplotes sp. grew well on the browntide. Maximum specific growth rate for F. salina of 0.52 d -1 was achieved at 1 mg C l -1of brown tide. However, the numerical response of F. salina to various concentrationsof the brown tide alga shows a decreasing growth rate at food concentrations above 1mg C l -1 , falling to 0.25 d -1 at 5 mg C l -1 (Figure 36). In contrast, F.salina fedIsochrysis galbana showed a more typical numerical response curve, with growth rateremaining high at higher food concentrations (maximum specific growth rate of 0.71 d -1at 5 mg C l -1. ) The ciliate Euplotes sp. showed a similar numerical response when fedthe brown tide alga. Maximum specific growth rates of 0.5 d -1 were observed at abrown tide concentration of 1 mg C l -1 , but specific growth rates fell to 0.29 at 5 mg C l -1 (Figure 37). Growth of Euplotes sp. was higher when fed I. galbana at 2.5 or 5 mgcarbon l -1 than when fed similar concentrations of the brown tide.The Texas brown tide alga did not support the growth of the heterotrophicdinoflagellate Noctiluca scintillans. However, there is no evidence that the brown tidealga is highly toxic to N. scintillans, since growth (death) rate was only -0.04 d -1 at 5 mgC l -1 of brown tide. Specific growth rates of N. scintillans on Thalassiosira sp. rangedfrom 0.38 d -1 for 0.1 mg carbon l -1 to 0.6 d -1 for 1.0 mg carbon l -1 (Figure 38). When amixture of Thalassiosira sp. and the brown tide alga was offered as food, the specificgrowth rate ranged from 0.22 d -1 to 0.38 d -1 . Even though total food concentration wastwice as high when equal amounts of brown tide and Thalassiosira sp. were offered asfood, growth rates were always lower than when N. scintillans were offeredThalassiosira sp. alone.37

Specific Growth Rate (day -1 )0.800.700.600.500.400.300.200.100.000.00 1.00 2.00 3.00 4.00 5.00Phtyoplankton Concentration (mg C/l)Fed Brown TideFed IsochrysisFigure 36. Specific growth rate (d -1 ) of the ciliate Fabrea salina on variousconcentrations of the Texas brown tide alga and on Isochrysis galbana. Adapted fromBuskey and Hyatt (1995).0.6Specific Growth Rate (day -1 )0.50.40.30.20.100 1 2 3 4 5Phytoplankton Concentration (mg C/l)Fed Brown TideFed IsochrysisFigure 37. Specific growth rates (d -1 ) of the ciliate Euplotes sp. on variousconcentrations of the Texas brown tide alga and on Isochrysis galbana. Adapted fromBuskey and Hyatt (1995).38

Specific Growth Rate (Day -1 )0.70.60.50.40.30.20.10-0.1-0.20 1 2 3 4 5Phytoplankton Concentration (mg C/l)Thalassiosira Brown Tide BothFigure 38. Specific growth rates (d -1 ) of the heterotrophic dinoflagellate Noctilucascintillans on various concentrations of the Texas brown tide alga, Thalassiosira sp. orequal concentrations of both species (twice the total food concentration). Adapted fromBuskey and Hyatt (1995).The small heterotrophic dinoflagellate Oxyhrris marina did not grow on browntide at food concentrations below 0.1 mg C l -1 , but grew well on higher concentration ofthis species (Figure 39). Maximum specific growth rates of 0.55 d -1 were observed at aconcentration of 5 mg C l -1 . However, O. marina grew faster on low concentrations ofIsochrysis galbana, and reached maximum growth at 0.5 mg C l -1 . Growth rates of O.marina were higher when fed equivalent concentrations of I. galbana than when fed thebrown tide alga at concentrations below 5 mg C l -1 (Figure 39).Specific Growth (day -1 )10.80.60.40.20-0.2-0.40 1 2 3 4 5Phytoplankton Concentration (mg C/l)Brown TideIsochrysisFigure 39. Specific growth rates (d -1 ) of the heterotrophic dinoflagellate Oxyhrrismarina on the Texas brown tide alga and on Isochrysis galbana. Adapted from Buskeyand Hyatt (1995).39

The Texas brown tide alga did not support the growth of the rotifer Brachionusplicatilus at any food concentration. Specific growth (death) rates were similar to thosefor rotifers that were starved over the same 3 day period (ca. -0.15 d -1 ). At a brown tideconcentration of 5 mg C l -1 , specific growth (death) rate decreased to -0.39. When therotifers were fed Isochrysis galbana, specific growth rates ranged from 0.19 to 0.61 d -1(Figure 40). However, when B. plicatilus was fed an equal amount of both I. galbanaand the Texas brown tide alga (yielding twice the total phytoplankton concentration), B.plicatilus showed little or no growth.Specific Growth Rate (day -1 )0.80.60.40.20-0.2-0.4-0.60 1 2 3 4 5Phytoplankton Concentration (mg C/l)Fed Isochrysis Fed Brown Tide Fed BothFigure 40. Specific growth rates (d -1 ) of the rotifer Brachionus plicatilus on the Texasbrown tide alga, Isochrysis galbana and equal concentrations of each (twice the totalfood concentration). Adapted from Buskey and Hyatt (1995).When groups of 36 Acartia tonsa nauplii were raised in 3 ml cell wells in tissueculture plates, the group held without any food exhibited daily mortality and were alldead by the end of a five day period. For a similar group of nauplii held in 3 ml ofseawater containing brown tide at a concentration of 5 mg C l -1 , there was extensivemortality on the second day, and all nauplii were dead by day 3. For groups of naupliiraised on 5 mg C l -1 of Isochrysis galbana, Pyrenomonas salina or a combination of thetwo foods, over 85% of the nauplii were still alive at the end of the 5 day period (Figure41). Since the brown tide appeared to settle to the bottom of the cell wells over thecourse of the experiment, subsequent experiments were done with groups of 50 naupliiin 50 ml tissue culture flasks rotated at 2 rpm to keep the algae in suspension.Replicate experiments were run at 2, 3.5 and 5 mg C l -1 . Survival of A. tonsa naupliiranged from 1% to 6% on the brown tide alone, from 70 to 83% on I. galbana alone andfrom 41 to 55% on a combination of equal amounts of each food (twice the foodconcentration) (Figure 42).40

Percent Survival10090807060504030201000 1 2 3 4 5Time (days)Starved Brown Tide IsochrysisPyrenomomos Iso & PryenFigure 41. Survival of groups of 24 nauplii of the copepod Acartia tonsa fed 5 mg C l -1of the Texas brown tide alga, Isochrysis galbana, Pyrenomonas salina, a combinationof I. galbana and P. salina or starved over a 96 hour period. Adapted from Buskey andHyatt (1995).0.9Proportion of Nauplii Surviving0.80.70.60.50.40.30.20.102 3.5 5Food Concentration (mg C/l)Isochrysis Brown Tide BothFigure 42. Survival of groups of 50 nauplii of the copepod Acartia tonsa fed Isochrysisgalbana, the Texas brown tide alga or a combination of both (twice the total foodconcentration) at food concentrations of 2, 3.5 and 5 mg C l -1 over a 96 hour period.Each bar is the mean value of two replicate experiments. Adapted from Buskey andHyatt (1995).41

Egg release rates for adult female Acartia tonsa fed the Texas brown tide alga ata food concentration of 1.5 mg C l -1 was 3.4 + 2.3 (mean + 1 SD, n=6) eggs per femaleper day, which was not significantly different from the egg release rates of 1.7 + 0.7 forA. tonsa that had been starved over the same 48 h period (t-test, p = 0.05). A. tonsafemales fed similarly sized small phytoplankton species showed intermediate eggrelease rates of 9.3 + 2.6 eggs per female per day when fed 1.5 mg C l -1 of Isochrysisgalbana (5 µm diameter) and 13.1 + 3.5 eggs per female per day when fed 1.5 mg C l -1of Emiliania huxleyi (4 µm diameter). Highest egg release rates of 25.9 + 7.2 eggs perfemale per day were measured for A. tonsa fed 1.5 mg C l -1 of the diatom Thalassiosirasp. When A. tonsa females were offered a combination of 1.5 mg C l -1 each ofThalassiosira sp. and the Texas brown tide alga (3 mg C l -1 total), egg release rateswere 26.9 + 3.6 eggs per female per day, which is not significantly different from therelease rate when the copepods were fed Thalassiosira sp. alone (t-test, α = 0.05)(Figure 43).3530Eggs/Female/Day252015105StarvedBrown TideIsochrysisEmilianiaThalassiosiraThal & Brown Tide0Figure 43. Mean egg release rates (eggs female -1 day -1 ) of adult female Acartia tonsafed 1.5 mg C l -1 of the Texas brown tide alga, Isochrysis galbana, Emiliania huxleyi,Thalassiosira sp., a combination of Thalassiosira sp. and brown tide, or starved. Eachbar represents the mean (+ SD) of eight replicate experiments. Adapted from Buskeyand Hyatt (1995).The Texas brown tide alga appears to be a poor food for a variety ofzooplankton species. It supports no growth of the ciliate Strombidinopsis sp., theheterotrophic dinoflagellate Noctiluca scintillans or the rotifer Brachionus plicatilus. It isnot unusual to find zooplankton that can not be cultured on a particular species ofphytoplankton; some can only capture particles in a relatively narrow size range(Fenchel, 1980). However N. scintillans can be grown on a wide range of phytoplanktonspecies, including species of similar size (Buskey, 1995) and B. plicatilus is an easy to42

culture organism widely used as a food for larval fish. Based on the results of thisstudy, there is evidence that the brown tide may be directly toxic to some species ofzooplankton, at cell concentrations similar to those found in nature. For the ciliateStrobidinopsis sp. (Figure 35) and for the rotifer B. plicatilus (Figure 40), mortality ratesincrease with increasing brown tide concentration. For one experiment with Acartiatonsa nauplii, mortality was faster in the presence of the brown tide than when no foodwas offered (Figure 41). Additional evidence for toxicity of the brown tide to somespecies of zooplankton comes from the decrease in survival of A. tonsa nauplii whenboth a suitable food (Isochrysis galbana) and the brown tide are offered together(Figure 42). In addition, when both I. galbana and the brown tide are offered together,growth of the heterotrophic dinoflagellate N. scintillans and the rotifer B. plicatilus areinhibited (Figures 38 & 40). In contrast, there is little evidence that the related speciesAureococcus anophagefferens is toxic to microzooplankton. No evidence was found forchanges in protozoan grazing rate or for suppression of growth in protozoans fed A.anophagefferens, nor was there any evidence that A. anophagefferens caused areduction in protozoan populations in nature (Caron et al., 1989).The brown tide alga appears to be a poor food item for Acartia tonsa, thedominant mesozooplankton in the Laguna Madre. Egg release rates of adult femalesfed the brown tide were not significantly different from those held without food over thesame time interval. This may have been due in part to the small size of the brown tidecells (4-5 µm diameter), which is outside the optimum size range for particle capture byA. tonsa (Berggreen et al., 1988). However, A. tonsa females produced an intermediatenumber of eggs on two similarly small sized algal species, indicating that size alonewas not the problem. There was no evidence of brown tide toxicity to adult female A.tonsa at 1.5 mg C l -1 , since there was no direct mortality to adults and egg release wasnot lowered with the combination of Thalassiosira and brown tide. Lower egg releaserates are reported for A. tonsa fed picoalgae during an A. anophagefferens bloom inNarragansett Bay, (Durbin and Durbin, 1989). In addition to lowering the egg releaserates of adult females, the presence of the brown tide resulted in lower survival of A.tonsa nauplii, suggesting toxic effects. The Texas brown tide alga has also been shownto be toxic to first feeding red drum and spotted sea trout larvae (G.J. Holt, personalcommunication) but it does not appear to have adverse affect on adult fish populations.Field evidence also supports the concept that the Texas brown tide alga is apoor food for zooplankton and disrupts trophic transfer in the planktonic food web.Mesozooplankton abundance (mainly Acartia tonsa) was lower in the Laguna Madreafter the brown tide began than in the preceding year, and adult female A. tonsa weresmaller and produced fewer eggs in field incubations than before the brown tide began(Buskey and Stockwell, 1993). Microzooplankton abundances were also lower after thebrown tide began, and microzooplankton community grazing rates of phytoplanktonstanding stock were reduced from ca. 95% to less than 5% during the brown tide(Buskey and Stockwell, 1993). It is still difficult to understand why species ofmicrozooplankton capable of growing on the brown tide have not flourished and helpedbring the brown tide under control. It is possible that A. tonsa may be exerting43

additional predation pressure on microzooplankton populations during the brown tide,due to the reduction of other species of phytoplankton in their preferred size range. It iswell documented that A. tonsa also feed on microzooplankton (reviewed in Pierce andTurner, 1992), so it is possible that they are holding microzooplankton populationsbelow a level where they can exert sufficient grazing pressure to help control the browntide.The related brown tide species, Aureococcus anophagefferens, has beendemonstrated to inhibit feeding and cause mass mortality of the mussel Mytilus edulis(Tracey, 1988). Bricelj and Kuenstner (1989) concluded that this mortality was due totoxicity and not to small size or nutritional inadequacy of this phytoplankton species.Laboratory studies also indicate that A. anophagefferens reduces growth and causeshigh mortality of bay scallop larvae (Gallager et al., 1989). A. anophagefferens wasshown to inhibit the cilliary activity of isolated gills of some bivalve species such asMercenaria mercenaria and Mytilus edulis but not others that were affected by browntide in nature such as Argopecten irradians (Gainey and Shumway, 1991). In contrast,the Texas brown tide alga is readily consumed by the dwarf surfclam Mulinia lateraliswithout adverse affects (Montagna et al., 1993), and there is no evidence that theTexas brown tide alga is toxic to adults of other species of invertebrates.It seems likely that the Texas brown tide alga may produce a chemical thatinhibits grazing or growth of microzooplankton, and/or may act as an allelopathic agentto reduce competition from other phytoplankton species. For example, bothAureococcus anophagefferens and the Texas brown tide contain high concentrations ofdimethylsulfoniopropionate (DMSP) which is a precursor to dimethylsulfide (DMS) andacrylic acid (Keller et al., 1989; Stockwell et al., 1993). The role of DMSP in grazerinhibition is unclear, however. For example, Phaeocystis pouchetii, which also producesa large amount of DMSP (Keller et al., 1989) appears to be consumed by a wide varietyof zooplankton (Admiraal and Venekamp, 1986; Huntley et al., 1987), whereasChrysochromulina polylepis, which produces DMSP reduces growth and feeding ratesof the tintinnid Favella ehrenbergii (Carlsson et al., 1990). The polysaccharide-likelayer on the surface of A. anophagefferens contains a bioactive compound responsiblefor the reduction in cilliary beat frequency in bivalve gills (Gainey and Shumway, 1991),but no similar compounds have yet been identified in the Texas brown tide alga.Many species of harmful and nuisance algae are toxic to a variety of marineorganisms. Most of the toxins associated with harmful algal blooms were first noticedbecause of the extensive fish kills they caused or for the human health risk associatedwith consumption of contaminated seafood. It is difficult to understand why algalspecies would evolve toxins that were specifically aimed at humans or fish species thatdo not directly consume these algal species. It is possible that in some cases thesetoxins might be substances that have evolved for some other physiological function inthe cell, which coincidentally happen to be toxic to human or marine life. In the cases ofAureococcus anophagefferens and the Texas brown tide alga, it appears as if toxicsubstances may be targeted at benthic and planktonic grazers that feed on these44

species of phytoplankton, and although there are no direct threats to human healthfrom these species, they may have a profound effect on the structure and function ofthe ecosystems in which they reside.3. Larval FishRed drum (Sciaenops ocellatus) and spotted seatrout(Cynoscion nebulosus)eggs and larvae were tested for survival, growth and feeding success in the presenceof brown tide by Dr. Joan Holt of the University of Texas Marine Science Institute. Testswere carried out both in the laboratory and in situ in the Texas Parks and Wildlife fishproduction ponds at the GCCA-CPL Marine Development Center. Eggs from laboratoryspawns placed in brown tide concentrations of 1 to 1.6 million cells per ml showedsignificantly reduced hatch rate and 2 or 3 day survival, compared to controls inseawater (Figure 44). Only 20% of spotted seatrout survived to day 3 post hatch. Reddrum eggs also showed significantly reduced hatch rates and reduced survival in bothlaboratory studies and in in situ studies at the GCCA-CPL Marine Development Center(Figure 45) although survival rates of controls were 100% in the laboratory and only20% on day two in the ponds. Eggs did considerably worse when placed in the pondscompared to the laboratory, probably due to high pH values, caused by the effects ofhigh photosynthetic rates on the carbonate cycle. Values ranged from 8.9 to 9.6 inponds with brown tide blooms, compared to normal seawater pH of 8.2. Studies areunderway to determine the effect of increasing pH on red drum egg and larval survival.Spotted Sea Trout% Survival1009080706050403020100EggDay1Day2Day3ControlBrown tideFigure 44. Survival of spotted seatrout eggs and early larvae in the presence andabsence of brown tide algae at a concentration of 1.6 million cells per ml. Unpublisheddata from Dr. G. Joan Holt, University of Texas Marine Science Institute.45

Red Drum% Survival1009080706050403020100Egg Day 1 Day 2Control (field) Brown Tide (field) Control (lab) Brown Tide (lab)Figure 45. Survival of red drum eggs and larvae in the presence and absence of browntide in both field and laboratory studies. Unpublished data from Dr. G. Joan Holt,University of Texas Marine Science Institute.Feeding studies were carried out with larvae from eggs hatched in normalseawater. Spotted seatrout larvae fed at significantly reduced rates in brown tide atages 5 to 7 days post hatch but not at day 14 (Figure 46).Feeding Rates: Spotted Seatrout10.000Prey Eaten/Hour8.0006.0004.0002.000controlBrown Tide0.000Day 5 Day 7 Day 14Figure 46. Feeding rates of larval spotted seatrout on rotifers at 5, 7 and 14 days posthatch,in brown tide water compared to bloom-free water. Significantly lower feedingrates were observed in the presence of the brown tide for 5 and 7 day old larvae.Unpublished data from Dr. G. Joan Holt, University of Texas Marine Science Institute.46

These results are particularly important for spotted seatrout that spawn in theLaguna Madre where high concentrations of brown tide occur, and to the red drumproduction ponds at the GCCA-CPL Marine Development Center. The overall effects ofbrown tide on larvae can be interpreted to show that eggs spawned in water with highbrown tide counts will not survive to first feeding and larvae that encounter high browntide concentrations in the first two weeks of life will suffer high mortality and reducedfeeding and growth rates.Field data collected by Mr. Scott Holt of the University of Texas Marine ScienceInstitute demonstrated that spotted seatrout larvae had reduced densities, averagedfrom 7 sites in the upper Laguna Madre (Figure 47), during the brown tide in 1992-1993 compared to collections from four months in 1989, before the brown tide began.Similar data from a site in the Port Mansfield channel (lower panel) where there was nomeasurable brown tide are quite variable, but there is no obvious reduction in larvaldensity between the same two time intervals.(b)Port Mannsfield Channel (East Cut)25(a)Laguna Madre Stations454035Density (No./ 100 m 3 )2015105Density (No./100m 3 )302520151005MarMayJulSepMayAugSepPre- Brown Tide | Post Brown Tide(1989) (92 - 93)JulSep0MarMayJulSepMayAugSepJulPre Brown Tide | Post Brown tide(1989) (92 - 93)SepFigure 47. A comparison of spotted seatrout larval densities in two areas of the LagunaMadre for pre- and post brown tide periods. Panel a shows monthly means for sevensites in the Laguna Madre, all of which were impacted by the brown tide. Panel b showssimilar data for a site in the Port Mansfield channel where there was no measurablebrown tide. Unpublished data of Scott Holt, University of Texas Marine ScienceInstitute.When larval density of spotted seatrout is plotted against brown tide cell counts,for samples taken in the upper Laguna Madre, there appears to be a trend ofdecreasing larval density with increasing brown tide density (Figure 48). When the47

density of black drum larvae is plotted against phytoplankton biomass measured aschlorophyll a concentration (Figure 49) there is a distinct pattern of lower larval densityat higher chlorophyll concentrations, which are areas most highly impacted by thebrown tide. In contrast, high chlorophyll concentrations seemed to have little impact onthe density of larval anchovy (Figure 50).Spotted Seatrout Larvae60Larval Density (No./100m 3 )504030201000 100 200 300Brown Tide (cellsx 10 4 /ml)Figure 48. Variations in density of larval spotted seatrout with brown tide cell counts forcollections from the Laguna Madre. Unpublished data of Scott Holt, University of TexasMarine Science Institute.Black Drum Larvae120Larval Density (No./100m 3 )1008060402000 10 20 30 40 50Chlorophyll (µg/l)Figure 49. Variations in density of black drum larvae with changes in phytoplanktonbiomass measured as chlorophyll a concentration, for collections in Laguna Madre.Areas of high phytoplankton biomass represent brown tide affected areas. Unpublisheddata of Scott Holt, University of Texas Marine Science Institute.48

Larval AnchovyLarval Density (No./100m 3 )90080070060050040030020010000 20 40 60 80Chlorophyll (µg/l)Figure 50. Variations in density of larval bay anchovy with changes in phytoplanktonbiomass measured as chlorophyll a concentration, for collections in Laguna Madre.Areas of high phytoplankton biomass represent brown tide affected areas. Unpublisheddata of Scott Holt, University of Texas Marine Science Institute.4. BenthosThe benthic organisms that live in the Laguna Madre include a large number offilter feeding invertebrates that could potentially have an important grazing impact onthe brown tide, given the shallow depth of the water column. Also since strongseabreezes from the Gulf of Mexico generally keep the water column well mixed,stratification of the water column generally does not occur. Thus, layering which couldisolate phytoplankton populations in surface water from potential grazers in the benthosdoes not occur.Biomass of the macrobenthos (defined as benthic organisms > 0.5 mm) isgenerally higher in the seagrass beds of Laguna Madre than in the mud-bottomhabitats of Baffin Bay (Figure 51). There was a decline in benthic biomass from >80 gdry weight per square meter to 40 species per 35 cm 2 before the brown tide began, and has remained at40 species or below since the brown tide began through 1992 (Figure 53). Diversity ofspecies in Baffin Bay has remained below 10 species per 35 cm 2 both before andduring the brown tide (Figure 53).49

Macrofauna BiomassBaffin Bay and Laguna Madre (all stations)Laguna Madre Biomass(g/m 2 )1009080706050403020100876543210Mar-89Jul-89Dec-89Apr-90Oct-90Feb-91Apr-91Jun-91Aug-91Oct-91Dec-91Apr-92Baffin Bay Biomass (g/m 2 )Oct-92Laguna MadreBaffin BayFigure 51. Macrobenthos biomass in Baffin Bay and the Laguna Madre from March1989 through October 1992. Unpublished data provided by Dr. Paul Montagna,University of Texas Marine Science Institute.Macrofauna AbundanceBaffin Bay and Laguna Madre(all stations)180000160000Abundance (#/m 2 )140000120000100000800006000040000200000Mar-89Jul-89Dec-89Apr-90Oct-90Feb-91Apr-91Jun-91Aug-91Oct-91Dec-91Apr-92Oct-92Baffin BayLaguna MadreFigure 52. Macrobenthos abundance in Baffin Bay and the Laguna Madre from March1989 through October 1992. Unpublished data provided by Dr. Paul Montagna,University of Texas Marine Science Institute.50

60Macrofauna DiversityBaffin Bay and Laguna Madre (all stations)12Laguna Madre Diversity (#Species)50403020101086420Mar-89Jul-89Dec-89Apr-90Oct-90Feb-91Apr-91Jun-91Aug-91Oct-91Apr-92Oct-92Baffin Bay Diversity(# Species)0Baffin BayLaguna MadreFigure 53. Macrobenthos diversity in Baffin Bay and the Laguna Madre from March1989 through October 1992. Unpublished data provided by Dr. Paul Montagna,University of Texas Marine Science Institute.The brown tide appears to have caused a reduction in macrobenthos biomassand abundance, and a reduction in species diversity in seagrass habitats. To the extentthat this reduction is in populations of filter feeding invertebrates (as opposed todeposit and detritus feeders), this reduction in benthos may have reduced grazingpressure on the brown tide alga (Montagna et al., 1993). The filter feeding molluskMulinia lateralis nearly disappeared from Baffin Bay during 1990 and 1991 (Montagnaet al., 1993). Montagna et al. (1993) found that adult Mulinia lateralis consumed thebrown tide alga as well as three cultured species of phytoplankton. It was furtherestimated that at its peak density before the brown tide began (800 per square meter),its maximum clearance rate of 10 ml per hour would allow this population of clams toclear a 1.2 m water column in 150 hours or about 6-7 days. However, since the browntide can double its population in 1-2 days under good growing conditions (Stockwell etal., 1993), even under ideal conditions these benthic filter feeders can not controlbrown tide populations.5. Adult fish and shellfish populations.The extended brown tide bloom had no apparent prolonged effect onpopulations of adult fish and shellfish . Game fish populations (red drum, black drum,and spotted seatrout) were sampled by gill net in the spring and fall (Figure 54). Thereis no apparent decline in the populations of these important recreational species; in factthere appears to be a substantial increase in black drum since the initiation of thebrown tide. Small forage fish (bay anchovy and striped mullet) and commerciallyimportant shellfish (brown shrimp and blue crab) populations were sampled by bag51

seine during the appropriate season (Figure 55). No prolonged decline in abundancehas occurred since the initiation of the brown tide. Each population did experience atemporary decline in abundance close to the time of initiation of the brown tide. Thisdecrease in numbers may represent the large fish kill caused by the December 1989freeze, and/or the effects of the extended drought in 1989.ANumber/hr54.543.532.521.510.508284Spring Gill Net Data(15 April-15 June)8688Year909294Red Drum Spotted Seatrout Black DrumBNumber/hr54.543.532.521.510.508284Fall Gill Net Data(15 Sept.-15 Nov.)8688Year909294Red Drum Spotted Seatrout Black DrumFigure 54. Seasonal average of three game fish species (red drum, spotted seatroutand black drum) based on spring (a) and fall (b) gill net sets at several randomlyselected locations within the Laguna Madre. Data provided by Larry McEachron andKyle Spiller, Texas Parks and Wildlife Department.52

ABay AnchovyBStripped Mullet250600Number/hectare20015010050Number/hectare50040030020010000798183858789919395798183858789919395YearYearCNumber/hectare160014001200100080060040020007981Brown Shrimp83858789Year919395DNumber/hectare250200150100500798183Blue Crab858789Year919395Figure 55. Seasonal average catch based on bag seine data at several randomlychosen sites within the Laguna Madre. Collection seasons for each species were: A.bay anchovy March-June, B. striped mullet May-June, C. brown shrimp April-July, D.blue crab March-June. Data provided by Larry McEachron and Kyle Spiller, TexasParks and Wildlife Department.The lack of adverse effects of brown tide on adult fish populations is in sharpcontrast to its apparent effects on larval fish populations. In a nearly enclosed systemsuch as the Laguna Madre, it might be expected that if larval fish abundance declined,adult fish populations would soon decline as well. Several possible explanations existfor this apparent paradox, but there is at present no way to determine which, if any, ofthe possible explanations is most plausible. For example, the brown tide may haveenhanced the survival of post-larval, juvenile fish by reducing their susceptibility tovisual predation by larger fish in the reduced visibility conditions associated with thebrown tide. Another contributing factor may have been reduced sports fishing pressurein brown tide affected areas, due to reduced success experienced by many anglers inthe low visibility waters. In addition, there have been no severe freezes affecting theLaguna Madre since the brown tide began, and increased fish populations may reflectrecovery of populations from the severe freezes in the 1980's. A ban on commercial netfisheries since the early 1980’s also could lead to the increase in adult population. It isalso possible that additional fish may have migrated into the Laguna Madre fromadjacent habitats not affected by the brown tide.53

IV. Identification of Probable CausesLaguna Madre is vulnerable to ecosystem disruption due to its lack of consistentfreshwater inflow, making hypersaline conditions likely during periods of extendeddrought. This propensity for extreme hypersaline conditions has been reducedsomewhat in recent decades by the construction of the Gulf Intracoastal Waterway.This channel allows, at least, a minimum amount of water exchange with the Gulf ofMexico.The long turnover times estimated for waters in Baffin Bay and Laguna Madreclearly contribute to the persistence of the brown tide bloom. The time required toexchange all the water contained within the Laguna Madre with adjacent areas in theGulf of Mexico and Corpus Christi Bay is on the order of one year. This makes itdifficult to disperse and dilute an algal bloom for a species that can easily double itspopulation in a matter of days if sufficient nutrients are available. There has been muchpublic discussion of the possibility of eliminating the brown tide through increasing thecirculation of the Laguna Madre by raising the John F. Kennedy Causeway or byopening new passes between the Gulf of Mexico and the Laguna Madre. In order forthese engineering projects to have an impact on the brown tide, they would have tosubstantially reduce the residence time of water in the Laguna Madre, from one year toa matter of weeks, as is the case in other Texas bays where the brown tide hasbloomed but not persisted (Shormann, 1992). Recent studies of the impact of raisingthe Kennedy causeway for the Texas Department of Transportation by Shiner, Moseleyand Associates indicate that the cost of raising the Kennedy causeway through most ofits length would be on the order of $50 million dollars, and that this major engineeringproject would have a minimal impact on the turnover time of water in the upper LagunaMadre. The total amount of water exchange may increase slightly, but the major impactwould be to spread this exchange over a wider area, compared to the two channels thatnow handle most of the exchange. Other suggested projects, such as reopeningYarborough Pass would also be expensive, initially and in terms of maintenance costs,and there is little evidence that they would increase circulation enough to eliminatedthe brown tide. By comparison, the lower Laguna Madre, which has better circulationthan the upper Laguna Madre due to major passes at Port Isabel to the south and PortMansfield to the north, still has persistent blooms of the brown tide. It would beinteresting to determine if the brown tide in lower Laguna Madre would persist withoutthe major pulse of brown tide pushed south each winter by the north winds of strongcold fronts.Laguna Madre fish populations are vulnerable to extensive die-offs during thepassage of severe cold fronts. Due to a shallow (1.2 m) average depth (Armstrong,1987), few deep water refuges and no direct passes to the Gulf of Mexico, extreme coldfronts, with below freezing temperatures, during winter can cause dramatic drops inwater temperature resulting in mass mortality of fish and benthic invertebrates (DeYoeand Suttle, 1994). It has been calculated that the nutrients released from the fish and54

invertebrate die-off in the freezes of December 1989 would have provided sufficientnutrients to explain the initiation of the brown tide bloom in January 1990. However,there has been much public discussion of the possible role of agricultural runoff fromthe King Ranch in the initiation and maintenance of the brown tide. A large amount ofland adjacent to the Laguna Madre is alleged to have been changed from grazing toagricultural use prior to the initiation of the brown tide, and concerns have been raisedthat runoff from this agricultural land may have contributed to the initiation of the bloom,and may be a continuing source of nutrients helping to maintain the bloom. Thispossibility has not yet been explored, but is currently under investigation by the TexasAgricultural Experiment Station and Corpus Christi Bay National Estuary Program.It is clear from studies of changes in the Laguna Madre ecosystem before andduring the initiation of the brown tide, that changes in biotic components of the LagunaMadre ecosystem also indirectly contributed to the initiation of the brown tide. A periodof extended drought in 1989 had raised the salinity in the upper reaches of Baffin Bayto >60 ppt. This is nearly twice the salinity of normal seawater, and many marinespecies cannot survive under these high salinity conditions. Population of zooplanktonand benthic organisms, the major feeders on water column algae, were declining priorto the onset of the brown tide. With depressed populations of planktonic and benthicgrazers, it became much easier for a major bloom such as the brown tide to get started,since the normal biological controls on algal growth were impaired. Once the bloombecame established, the algae was capable of growing faster than the grazers couldremove it.There are indications that the brown tide alga is toxic to some species ofplanktonic grazers, and this resultant reduction in grazing pressure may help the browntide bloom persist. In particular, it appears that brown tide concentrations above athreshold concentration of approximately one million cells per ml are either directlytoxic to some species of zooplankton or inhibit their growth (Buskey and Hyatt, 1995).Additional research on the potentially toxic effects of brown tide on marine organisms,including their planktonic and benthic grazers and larval fish is needed.V. Identification of Data and Information GapsCompared to the body of information available on blooms of the East Coastbrown tide alga Aureococcus anophagefferens, very little research has been performedon the Texas brown tide alga to date. Initial strong support of research efforts by theTexas Higher Education Coordinating Board (THECB) have provided a wealth ofinformation about conditions before and during the initiation of the Texas brown tide.This is unique among studies of harmful algal bloom phenomena; usually studies donot begin until the bloom is already under way and recognized as a potential problem.The studies funded by the THECB also clearly documented the initial changes in theLaguna Madre ecosystem caused by the bloom, but much remains to be learned.55

In particular, it is clear that very little is known about the autecology of the algaitself. For scientists, one clear indication of the lack of interest in this algal species itselfis that after over five and one half years of algal bloom, this species has still not beentaxonomically described. It is an embarrassment to everyone working with the browntide that we still can only refer to it as the "brown tide alga". A taxonomic description ofthis species is critical to scientific communication, so that scientists can potentiallyidentify this species from other parts of the world. Fortunately, a taxonomic descriptionwill soon be published (DeYoe, personal communication).Most studies of the brown tide alga have been field studies of biomassdistributions and primary production rates (Stockwell and Whitledge, unpublished), andthe only studies of the alga under laboratory conditions are those of DeYoe and Suttle(1994) who provided important insights into the nutrient requirements of this species,and DeYoe et al. (1995) that examined gene sequences to examine the taxonomicrelationship of this species to other algal taxa. Additional isolates of this alga need tobe brought into culture, and a systematic study of the factors affecting its survival andgrowth needs to be undertaken. Since this species, like the East Coast brown tideAureococcus anophagefferens is not readily cultured under conditions suitable formany other phytoplankton species (e.g. it does not grow well in f/2 media) a study ofmicronutrient requirements, including trace metals and vitamins could provide importantinsights into the conditions that favor the growth of this species.VI. Recommendations for priority research and monitoring effortsA. Research1. To study and define the autecology of the brown tide alga in terms of the physicaland chemical factors that affect its growth. Specifically to look at the effects oftemperature, salinity, light intensity, macro- and micronutrients on the growth rate of thebrown tide.2. To identify possible toxins and/or inhibitory chemicals produced by the brown tideorganism, their affects on the growth of other phytoplankton species (possibleallelopathic effects) and on the survival, growth and feeding of potential grazers on thebrown tide, including both planktonic (micro- and mesozooplankton) and benthicgrazers. It should be emphasized that potential toxic effects should be examined on alllife history stages of grazers, including the planktonic larvae of benthic macrofauna.Further study of the potential toxic effects of the brown tide on larval fish is alsoneeded.3. A method for positively identifying the Texas brown tide alga needs to be developed,such as a fluorescently labeled polyclonal antibody marker with high specificity for thebrown tide, or a fluorescently labeled genetic marker, specific to a particular uniquegenetic sequence in the DNA or RNA of the brown tide alga. Using these methods, thebrown tide alga could be positively identified at low cell concentrations to determine if it56

is a common component of phytoplankton communities throughout the coastal zone ofTexas and other areas of the Gulf of Mexico. Such a marker would also be useful foridentifying brown tide cells in the stomach contents of grazers from protozoa tomacrofauna, to help determine the extent to which natural grazer populations feed onthe brown tide.4. To investigate the use of various biological agents to help control brown tidepopulations, including planktonic and benthic grazers and possible pathogens such asviruses specific to the brown tide alga. It is doubtful if these agents could be used toeliminate the brown tide during periods of its peak abundance and extent, but they maybe useful for breaking up seed populations during periods of low natural abundance ofthe brown tide and could also prove useful as control agents in mariculture facilitieswhere the area that needs to be treated is small.5. To investigate the role of non-point source pollutants, including fertilizer andpesticide runoff from agricultural areas on the growth and maintenance of brown tideblooms and associated plankton populations.6. Historical studies of the Laguna Madre should be pursued to determine the historicalimportance of seagrass-based primary production versus phytoplankton based primaryproduction in the Laguna Madre over the past several thousand years. If this can betied in to data on paleosalinity and paleotemperature, as well as information on theoccurrence of major hurricanes (via the sand deposits they leave in the sedimentrecord) the importance of circulation with the Gulf of Mexico on the dominance ofseagrass or phytoplankton can be determined. If biomarkers specific to diageniccompounds associated with the brown tide alga can be identified, it may also bepossible to determine if the brown tide alga has bloomed for extended periods in thepast.B. Monitoring1. Continued monitoring of the areal distribution of seagrass beds in the Laguna Madremust be made so that the impact of the brown tide on the Laguna Madre ecosystem canbe assessed.2. Continued monitoring of the effects of the brown tide on the structure and function ofthe Laguna Madre ecosystem, especially finfish populations, will provide us with abasis for cost/benefit analysis for potential management strategies for dealing with thebrown tide.3. Continued monitoring of the distribution and abundance of the brown tide willincrease our knowledge of the factors influencing the persistence of this bloom.57

4. A monitoring plan should be designed to quantify non-point source pollutants,including pesticides and fertilizers, and help identify their sources.58

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Milligan, A.J. (1992). An investigation of factors contributing to blooms of the "browntide" Aureococcus anophagefferens (Chysophyceae) under nutrient saturated, lightlimited conditions. M.S. Thesis, State University of New York at Stony Brook, 84pp.Montagna, P.A., Stockwell, D.A., Kalke, R.D. (1993). Dwarf surfclam Mulinia lateralis(Say, 1822) populations and feeding during the Texas brown tide event. J. ShellfishRes. 12: 433-442.Nuzzi, R., Waters, RM. (1989). The spatial and temporal distribution of "brown tide" ineastern Long Island Sound. In: Novel phytoplankton Blooms, E.M. Cosper, V.M. Briceljand E.J. Carpenter (eds). Coastal and Estuarine Studies 35, Springer-Verlag, Berlin. p.117-138.Odum, H.T. and Wilson, R. (1962) Futher studies on reaeration and metabolism ofTexas bays, 1958-1960. Publ. Inst. Mar. Sci. Univ. Texas. 8: 23-55.Olsen, P.S. (1989). Development and distribution of a brown-water algal bloom inBarneget Bay, New Jersey with perspective on resources and other red tides in theregion. In: Novel phytoplankton Blooms, E.M. Cosper, V.M. Bricelj and E.J. Carpenter(eds). Coastal and Estuarine Studies 35, Springer-Verlag, Berlin. p. 189-212.Onuf, C.P. (1995). Seagrass responses to long-term light reduction by brown tide inupper Laguna Madre, Texas: Distribution and biomass patterns. Mar. Ecol. Prog. Ser.(Submitted).Onuf, C.P. (1991). Light requirements of Halodule wrightii, Syringodium filiforme, andHalophila engelmanni in a heterogeneous and variable environment inferred from long -term monitoring. In: The light requirements of seagrasses: proceedings of a workshopto examine the capability of water quality criteria, standards and monitoring programsto protect seagrasses, Kenworthy, W.J., Haunert, D. (eds). U.S. Department ofCommerce, National Oceanic and Atmospheric Administration, National MarineFisheries, NOAA Technical Memorandum MMFS-SEFC-287, p. 95-105.Pierce, R.W., Turner, J.T. (1992). Ecology of planktonic ciliates in marine food webs.Rev. Aquat. Sci. 67: 1710-1714.Quammen, M.L., Onuf, C.P. (1993). Laguna Madre: seagrass changes continuedecades after salinity reduction. Estuaries 16: 303-311.Shormann, D.E. (1992). The effects of freshwater inflow and hydrography on thedistribution of brown tide in South Texas. M.A. Thesis, Department of Marine Science,University of Texas at Austin,, 112 pp.Sieburth, J. McN., Johnson, P.W. (1989). Picoplankton ultrastructure: A decade ofpreparation for the brown tide alga, Aureococcus anophagefferens. In: Novel63

phytoplankton Blooms, E.M. Cosper, V.M. Bricelj and E.J. Carpenter (eds). Coastal andEstuarine Studies 35, Springer-Verlag, Berlin. p. 1-22.Sieburth, J. McN., Johnson, P.W., Hargraves, P.E. (1988). Ultrastructure and ecologyof Aureococcus anophagefferens gen. et sp. nov. (Chrysophyceae); the dominantpicoplankter during a bloom in Narragansett Bay, Rhode Island, summer 1985. J.Phycol. 24: 416-425.Simmons, E.G. (1957). An ecological survey of the upper Laguna Madre of Texas.Publ. Inst. Nar. Sci. Univ. Tex. 4: 156-200.Smayda, T.J., Villareal, T.A. (1989). The 1985 "brown tide" and the open phytoplanktonniche in Narragansett Bay during summer. In: Novel Phytoplankton Blooms, E.M.Cosper, V.M. Bricelj and E.J. Carpenter (eds). Coastal and Estuarine Studies 35,Springer-Verlag, Berlin. p. 159-188.Smith, N.P. (1985). Numerical simulation of bay-shelf exchanges with a onedimensionalmodel. Contr. Mar. Sci. 28: 1-15.Stockwell, D.A. (1989). Nitrogen Processes Study (NIPS): Effects of freshwater inflowon the primary production of a texas Coastal Bay System. Technical Report No. TR89-010, (UT Marine Science Institute, Port Aransas, Texas) 180 pp.Stockwell, D.A., Buskey, E.J., Whitledge, T.E. (1993). Studies on conditions conduciveto the development and maintenance of a persistent "brown tide" in Laguna Madre,Texas. In: Toxic Phytoplankton Blooms in the Sea. T.J. Smayda and Y. Shimizu (eds.),Proc. 5th Int. Conf. Toxic Marine Phytopl. Amsterdam, Elsevier. p. 693-698.Tracey, G.A. (1988). Feeding reduction, reproductive failure, and mortality in Mytilusedulis during the 1985 "brown tide" in Narragansett Bay, Rhode Island. Mar. Ecol. Prog.Ser. 50: 73-81.Virnstein, R.W. (1982) Leaf growth rate of the seagrass Halodule wrightiiphotographically measured in situ. Aquat. Bot. 12: 209-218.Wenczel, P. (1987). Proposed bay scallop reseeding activities for 1987. Reportsubmitted to New York State Development Corporation, New York, 28 pp.Whitledge, T.E., Malloy, S.C., Patton, C.J., Wirick, C.D. (1981). Automated nutrientanalyses in sewater. Format Report 51398, Brookhaven National Laboratory, Upton,NewYork, 216pp.Whitledge, T.E. (1989). Nitrogen Processes Study (NIPS): Nutrient distributions anddynamics in Lavaca, San Antonio and Nueces/Corpus Christi Bays in relation to64

freshwater inflow. Technical Report No. tr/89-007, (UT Marine Science Institute PortAransas, Texas) 211pp.Whitledge, T.E, (1993). The nutrient and hydrographic conditions prevailing in LagunaMadre, Texas before and during a brown tide bloom. In: Toxic Phytoplankton Blooms inthe Sea. T.J. Smayda and Y. Shimizu (eds.), Proc. 5th Int. Conf. Toxic Marine Phytopl.Amsterdam, Elsevier. p. 711-716.65

VIII. Introduction to harmful red tides in Texas watersApart from brown tides, red tides comprise the other common harmful algal bloom inTexas coastal waters. Red tides are caused by blooms of dinoflagellates that at highdensities can produce colors from yellow to reddish-brown in the water. The cells areattracted to light and actively swim toward the surface where they may be concentratedto high densities by wind, currents and tides (Tester and Fowler, 1990). No more thantwenty dinoflagellate species are thought to be toxic (Steidinger, 1979), providingsources of poisonous compounds that during a bloom that can cause mass mortalitiesof marine organisms and can lead to human health problems when contaminatedseafoods are consumed or aerosol toxins are inhaled. Toxic red tide blooms occurthroughout the world but are relatively rare in Texas coastal waters. So far, there havebeen two species of dinoflagellates responsible for toxic red tides in Texas: theunarmored Gymnodinium breve (formerly Ptychodiscus brevis) and Alexandrium(formerly Gonyaulax) monilata, an armored, chain-forming species. Typically,Gymnodinium breve first blooms in the Gulf of Mexico at least several miles off thecoast. Currents may move these blooms to shore and/or into coastal bays, and bloomconcentrations can persist from one week to several months. Blooms may be confinedto a particular bay or estuary (typical of A. monilata) or may spread to cover a massivearea of coastal waters and embayments (as with G. breve). The toxins in both of thesedinoflagellate species can cause extensive mortality in fish and invertebrates, but inTexas, only Gymnodinium breve red tides have been reported to cause human healthproblems in the forms of temporary respiratory irritation from aerosol toxin andneurotoxic shellfish poisoning (NSP). The toxin commonly becomes an aerosol whencells are ruptured by wave action, as in heavy surf, with toxin or toxin-laced cellfragments carried into the air with water vapor and/or minute salt particles. NSP resultsfrom consuming raw or cooked oysters, clams or mussels contaminated with what iscommonly called "brevetoxin." The symptoms, including nausea, dizziness andtingling in the extremities, go away in a few days; no deaths have been reported due toNSP (Steidinger, 1983).Both Alexandrium monilata and Gymnodinium breve undergo sexual as well asasexual reproduction. The possibility that blooms initiate in these red tide species frombenthic resting cysts known as hypnozygotes is likely, though the factors that triggerexcystment of the hypnozygotes are yet unknown. The sexual cycle in A. monilatainvolves production of two motile, isogamous, haploid gametes from each singlehaploid asexual cell. The fusion of two gametes produces first a double-flagellated,diploid planozygote, then a hypnozygote; excystment releases one cell that soondivides asexually into a small chain of four, but whether meiosis re-establishes haploidybefore or after excystment is not known (Walker and Steidinger, 1979). The G. brevesexual cycle is similar. Haploid cells form isogamous gametes which, upon pairing andfusion, produce diploid planozygotes (Walker, 1982). In the same study, Walker wasunable to induce hypnozygotic cyst formation from the planozygotes, and to date,neither laboratory cultures nor sediment analyses have documented the existence of G.breve hypnozygotes (K. A. Steidinger, pers. comm.).66

IX. Historical trends of Texas red tidesRed tides appear to be infrequent events in the CCBNEP area. Preliminaryinvestigations indicate that only four Gymnodinium breve and six or seven Alexandriummonilata blooms have been documented along the entire Texas coast since the majorred tide of 1935 (Snider, 1987; the ambiguity regarding the number of A. monilata redtides stems from the non-published sources of information available to Snider).Whereas G. breve blooms have been relatively well-studied, given the extent of theirnegative impact on fish and shellfish in Texas and their frequent recurrence off WestFlorida, A. monilata blooms, which have not contaminated shellfish, have not been sowell-documented. Before the apparent 1935 red tide, the relationship between fish killsand dinoflagellate blooms was not completely understood, making the causes of fishkills difficult to determine prior to that time.A. Frequency1. Offshore blooms of Gymnodinium breve in TexasThe mass mortality of fishes from the end of June to mid-September of 1935along the South Texas coast was not documented as linked to a dinoflagellate bloom(Lund, 1936; cf. Steidinger and Joyce, 1973), but, given Lund's report of an associatedaerosol irritant ("irritating 'gas'") in the absence of a positive species identification, thisbloom was almost certainly due to G. breve (Snider, 1987). Newspaper reports at thetime indicate that local scientists varied in their opinion of the cause of the fish kill. Dr.E.J. Lund of the University of Texas blamed it on low salinity waters along the coast,while Dr. C.J. Reed of Texas A&I University blamed it on a bloom of diatoms whichwas clogging the gills of fish and causing them to suffocate. Local fishermensuspected that canisters of poison gas left over from the First World War were finallydecomposing and releasing their deadly fumes. Others suspected release of gasesassociated with volcanic activity (Corpus Christi Caller times, Houston Chronicle,Houston Post, and San Antonio Evening News).Whereas two to three other suspected red tide blooms occurred in Texas waterswithin the two decades after 1935 (Gunter, 1951), the next major bloom occurred inSeptember of 1955. As indicated by fish mortality, the bloom ranged from 18 milesnorth of Port Isabel to the coastal waters of the adjacent Mexican coastal state ofTamaulipas. Highest reported densities of the causative species, G. breve, werefound 36 miles south of the Rio Grande River mouth at >22,000 cells/ml (Wilson andRay, 1956). Wilson and Ray (1956) offer no indication that the bloom originated inTexas waters and proceeded south or vice versa, though their short publication doesimply a Texas origin.The red tide of 1974 is the poorest documented of the four major bloom eventsin South Texas. The Port Isabel/South Padre Press on 10 October 1974 reported thatthe bloom was sighted south and east of Brownsville/Matamoros some 150 miles off67

the coast, causing a massive fish kill that eventually littered Mexican beaches, butgave no indication of its duration. The causative organism was not identified, but maywell have been Gymnodinium breve.This major Gymnodinium breve bloom lasting from the end of August to lateOctober of 1986 is arguably the worst yet experienced along the Texas coast witheffects stretching from its inception near Galveston Island to Mexico. Along MustangIsland Beach alone, investigators estimated 100,000 dead fish per linear mile over 14miles of beach; the Rockport harbor boat basin produced water samples with up to 1.1million G. breve cells/ml, concentrations almost certainly due to physical factors suchas wind-driven currents (Trebatoski, 1988).2. Inshore blooms of Gymnodinium breve in TexasThere has been one prominent G. breve bloom in inshore waters. On 16December 1990, the Brownsville Herald newspaper began a series of reports on watersampling by health and marine officials in the Brownsville Ship Channel in response toa previous fish kill in November, and though the newspaper was not specific, thesuspected causative organism was identified by Dr. Eleanor Cox at Texas A & M asGymnodinium breve (Roy Lehman, pers. comm.). While the ship channel remainedclosed to shellfishing, G. breve concentrations apparently dropped below detectionlevel shortly before the Herald's final report on this red tide on 12 April 1991.According to records from the Shellfish Sanitation Division of the Texas Department ofHealth, there have been problem concentrations of G. breve at other times and placesforcing closure of shellfish beds, yet most of these blooms seem to have escaped widernotice. For instance, from 25 August to 2 September 1990, Aransas and Copano Bayswere closed to shellfish harvesting due to a short-lived G. breve bloom (see Table 4 inSection III. E.). Table 4 highlights some of the more prominent commercial harvestingareas affected by the closure and reopening of their shellfish beds. Though the lowfrequency of major offshore blooms suggests that conditions favorable for initiation donot commonly occur in South Texas waters, the many closures of shellfish beds by theTexas Department of Health imply that G. breve blooms occur with greater frequencythan is commonly realized (G. Heideman, pers. comm.). Table 1 offers further supportfor more frequent blooms by listing selected dates on which shellfish meats fromvarious Texas bays caused the death of one or more mice used in the brevetoxinbioassay. The dates in Table 1 were selected because they do not coincide with thedurations of the well-documented G. breve red tides discussed throughout this reportand because they may represent a higher frequency of bloom concentrations largelyunnoticed except by the Shellfish Sanitation Division of the Texas Department ofHealth.68

Table 1. Selected Texas bays with prominent commercial shellfish beds matched with dates on whichsamples of shellfish meats proved fatal to one or more mice in the brevetoxin bioassay used by the TexasDepartment of Health. (Data courtesy of G. Heideman, Texas Department of Health.)Matagorda EspirituSantoSan Antonio Copano CorpusChristiNueces South3/3/876/24/878/14/873/4/87 2/15/873/4/874/1/87 4/2/878/17/874/2/878/17/871/27/888/18/883/6/913. Comparative frequencies of G. breve bloomsSimply determining the average frequency of Gymnodinium breve red tides fromthe four major offshore blooms gives a rough mean occurrence of one major bloom offthe Texas coast every 17 years with a standard deviation of 3 to 4 years. Whencompared to a recent detailed list of apparent G. breve red tides off the southern WestFlorida coast, blooms or near blooms were reported in a total of 65 months from 1975-1991 with 46% of those reports occurring in September, October and November(Abdelghani, 1994; Figure 1).No. of Occurrences Recorded121086420MayJunJulAugSepOctNovDecJanFebMarAprFIGURE 1. Cumulative recorded occurrences per month of Gymnodiniumbreve blooms from 1975-1991 in West Florida(Data from Abdelghani, 1994)What Abdelghani's (1994) unpublished draft report does not indicate is whether anymortality was associated with any report of higher than normal G. breve concentrationsin that span of time; shellfish harvesting areas were closed on at least severaloccasions. Rounsefell and Nelson (1966) found records of 17 toxic red tides onFlorida's west coast between 1844 and 1960; the adjective "toxic" may imply marinemortality. Joyce and Roberts (1975) state that about 30 red tides occurred in Floridawaters between 1844 and 1974, an average of one every four to five years, but theymake no mention of mortality and can only attribute those since 1946 to G. breve. Onemay easily calculate that about 13 red tides occurred off West Florida between 1960and 1974, but whether that comparatively high rate is due to an increase in bloomevents or improved detection is debatable (Hallegraeff, 1993; Anderson, 1994). For69

further comparison, Gunter (1951) reported that red tide-induced mortalities of marinelife along the West Florida coast tended to occur once every 10 years on average withdelays of up to 30 years, far more similar to the Texas experience.4. Alexandrium monilata blooms in TexasDocumentation of Alexandrium monilata blooms in Texas is less available thanthat for G. breve. Connell and Cross (1950) discussed the correlation of mass mortalityof fish with a 1949 episode of red tide in Offats Bayou near Galveston. Such summerfish kills had been documented in the bayou from 1936 to 1941 by Gordon Gunter, andlocal fishermen, who claim that summer mortality had been an almost annualoccurrence since as early as 1929. The organism Connell and Cross (1950) describedoccurred in chains and was similar but not identical to Gonyaulax catenella. Usingsamples mainly from the Indian and Banana Rivers on Florida's east coast, Howell(1953) described a small dinoflagellate species known to form chains of up to 40 cellsin length, and in early September of 1952, Howell found identical chain-formingdinoflagellates in a sample taken from Offatts Bayou. Whereas there was some debateover the proper generic classification at the time, what Connell and Cross (1950) andHowell (1953) described as a Gonyaulax species is now known as Alexandriummonilata. There are reports of "annual" blooms in the East Lagoon of Galveston Island(Marvin, 1965; Proctor, 1965; Proctor, 1966; Ray and Aldrich, 1967) and twoconsecutive blooms offshore of Galveston in 1971-72 (Wardle, Ray and Aldrich, 1975).Since the 1971-72 blooms, A. monilata has not reappeared in bloom concentrations inthe Galveston area (W. J. Wardle, pers. comm.), though local blooms have occurred invarious parts of South Texas. Jensen and Bowman (1975) state that a colleague at theTexas Water Quality Board had documented an A. monilata bloom and fish kill in theViola Turning Basin of the Corpus Christi Inner Harbor in the fall of 1972. An A.monilata bloom reappeared in the Viola Turning Basin in the summer of 1975, firstdetected by routine monitoring at what became the maximum recorded concentration of5.14 million cells/liter (Jensen and Bowman, 1975).B. Duration1. Gymnodinium breveThe G. breve red tide of 1935 was detectable from 30 June to 13 August, thefirst report coming from Padre Island and the last from the coast at the northern tip ofMatagorda Bay, a total of 45 days (Lund, 1936). The apparent 1955 G. breve red tidelasted for more than 12 days in September, but Wilson and Ray (1956) do not specifywhen the fish kill was first noticed nor when fish mortality ceased off the TamaulipasCoast of Mexico. No duration could be determined for the 1974 red tide 150 milesoffshore and southeast of Brownsville. The Brownsville Inner Harbor bloom of G. brevereported by Jensen and Bowman (1975) began to recede after about two months butlingered for perhaps two more months. The Coast Guard first noted the 1986-87 redtide as what appeared to be an oil slick washing ashore at the southern tip of70

Galveston Island on 27 August 1986; the subsequent large-scale event ceased 57 dayslater (Trebatoski, 1988). Trebatoski (1988) also noted that a dense, isolatedrecurrence appeared on 8 January 1987 in Corpus Christi Bay but apparently did notpersist past 4 February (Texas Department of Health). In comparison, the impliedduration of reported red tide bloom concentrations (apparently all G. breve) along theWest Florida coast from 1975-1991 ranged from "brief" to approximately seven months,the latter in 1980 (Abdelghani, 1994).2. Alexandrium monilataThe 1972 A. monilata bloom in the Viola Turning Basin of the Corpus ChristiInner Harbor lasted from August to September; the 1975 resurgence of A. monilata inthe same location persisted from July to September (Jensen and Bowman, 1975).During the 1975 bloom, cell counts and the number and length of A. monilata chainsgenerally decreased throughout the inner harbor until no longer detectable on 17September, but a fish kill did occur in the turning basin on 22 August, despite the smallconcentrations of A. monilata detected there at that time (Jensen and Bowman, 1975).C. Environmental effects1. CommercialThe most immediate negative economic impact of red tide blooms is fish andinvertebrate mortality. Aquaculture projects are especially susceptible to the toxins byvirtue of stock density and potentially catastrophic loss of investment (Steidinger andVargo, 1988; Shumway, 1990). Two experimental studies with both Gymnodiniumbreve and Alexandrium monilata illustrate the probable impact of the respective toxinson organisms of commercial value in the field. Sievers (1969) exposed several kindsof marine animals to concentrations of G. breve and A. monilata cultures fromundiluted to 90% dilution over 48 hours to determine the comparative toxicity of eachin terms of mortality. Fish were quite sensitive to both toxins (especially so to G. brevetoxin), crustaceans were resistant to both, and both annelids and mollusks were moresensitive to A. monilata toxin, including the American oyster (Crassostrea virginica)and a mussel (Brachidontes recurvus). The oysters and mussels immediately failed toopen upon exposure to lower dilutions of A. monilata cultures and suffered highmortality in undiluted cultures. Ray and Aldrich (1967) indicate that such mortality mayarise simply because the bivalves cannot maintain shell closure well past 24 hours. Intheir 24-hour laboratory study, oysters remained tightly closed almost constantly whilein A. monilata cultures. Chicks were not poisoned by ingestion of the oysterhomogenate, even when the homogenate was combined with actual A. monilata cellsor prepared from oysters exposed to an in situ bloom of A. monilata. In the samestudy, three of four oysters exposed to G. breve cultures filtered and consumed cellsafter some delay in opening; five grams of the subsequent oyster homogenate forcefedto each of four chicks proved fatal to all within 24 hours.71

In 1971 and 1972, A. monilata blooms occurred not far offshore of Galveston,producing high numbers and a wide variety of dead and dying marine organisms,including the commercially important blue crab, Callinectes sapidus (both years), thestone crab, Menippe mercenaria (both years), and the oyster, Crassostrea virginica(1972 only; Wardle et al., 1975). Though the findings of Wardle et al. (1975) indicatethat crustaceans are not immune to mortality induced by A. monilata blooms, otherdinoflagellate toxins (including brevetoxin) are not known to cause mortality orcontaminate the meat, so crabs, shrimp and lobsters are marketable even at the heightof toxic blooms (Roberts et al., 1979, re brevetoxin; Shumway, 1990).Edible bivalve mollusks are another matter, and the public health implications ofcontaminated bivalve meats can close lucrative fisheries temporarily, on a seasonalbasis or indefinitely. Shumway (1990) reviews sources that document a worst-casescenario in Alaska. With tens of thousands of miles of coastline and over 100 clamspecies, the Alaskan clam industry produced millions of pounds of shellfish productsuntil it was forced to close permanently shortly after World War II because of toxic redtide problems. When the Gulf Stream transported G. breve cells or cysts from WestFlorida to the Carolinas in 1987, the resultant bloom closed shellfish beds for the firsttime in North Carolina's history and caused losses of $20 million (Anderson, 1994).Efficient monitoring programs, however, enable some shellfish aquaculture efforts tocontinue safely in spite of recurrent blooms, exemplified by successful mussel culturesin the northeastern United States and in the Japanese scallop industry (Shumway,1990); this may be the only way to effectively reduce the negative economic impact oftoxic dinoflagellates on bivalve fisheries.The remaining problem for shellfish beds exposed to G. breve blooms isthe necessary ban on harvesting for up to two months or until tests indicate that themeat is no longer toxic (Steidinger and Ingle, 1972). In 1990, Tester and Fowlerpointed out that the U. S. Food and Drug Administration's interpretation of theAmerican Public Health Association guidelines regarding an acceptable amount ofNSP in shellfish contaminated by G. breve was more conservative than that forshellfish contaminated with the potentially lethal PSP toxin (paralytic shellfishpoisoning, caused by numerous other dinoflagellate species). In spite of theirrecommendation that the acceptable amount of NSP toxin in shellfish be equated withthat for PSP toxin, given the more than acceptable public health risk in doing so(Tester and Fowler, 1990), the FDA to date has not acted upon that recommendation(P. A. Tester, pers. comm.). In effect, the overly conservative restriction increases thenegative economic impact produced by G. breve blooms on the shellfish industry bykeeping shellfish beds closed for longer periods than truly necessary.Steidinger and Vargo (1988) also cite adverse impacts on tourism, real estateand seafood sales in areas suffering from G. breve red tides. Jensen (1975)discussed the economic impact as not just a problem for the affected area but insurrounding states as well because of the "halo effect." His example was the G.tamarensis (PSP) red tide of 1972 in New England. The affected New England states72

quickly banned harvest and shipment of their shellfish, but despite the fact that noblooms affected New York waters, many citizens of that state responded irrationally byrefusing to buy New York lobster, shellfish and finfish, avoiding Long Island seafoodrestaurants and causing a drop in the wholesale price for clams harvested fromunaffected areas. Jensen (1975) concludes that, if necessary an efficient means existwith which governmental agencies can quickly note the occurrence and distribution ofred tide blooms, what remains is for the seafood industry and the government to stemrumors and counteract misinformation with accurate and current facts about any toxicblooms, curtailing the "halo effect" that needlessly increases the scale of the negativeeconomic impact.Both A. monilata and G. breve possess icthyotoxins that threaten game and foodfish populations in the Gulf of Mexico. Using juvenile mullet (Mugil cephalus) as theirbioassay, Gates and Wilson (1960) noted mortality within 4.5 hours in all aliquots of invitro cultures of A. monilata (some aliquots containing cells and/or cell fragments andothers not) except the uninoculated control medium. Quick and Henderson (1975) didnot completely list the fifteen species they necropsied during an extended G. breve redtide from October 1973 through June 1974 along the west coast of Florida, but mullet,ladyfish and anchovies were mentioned. Enormous numbers of fish of even greatersport or commercial value were estimated to have died as a result of the 1986 G.breve red tide along the Texas coast (Texas Parks and Wildlife Department, 1986; seeTable 3.), including greater than 40,000 individuals each of red drum and southernflounder, about 80,000 spotted seatrout and more than 3.2 million Gulf menhaden.Riley et al. (1989) report that G. breve blooms can also reduce red drum recruitmentduring spawning periods; their source of red tide was the 1986 Texas bloom whichachieved average peak densities of 7000 cells/ml with concentrations of almost 5 x 10 4cells/ml in isolated patches in bays near Port Aransas throughout October. Theyshowed that G. breve caused paralysis and death in laboratory-spawned and wildcaughtred drum larvae at all concentrations above 40 cells/ml. Since both A. monilataand G. breve cause fish mortality, an extensive bloom of either can produce acorresponding loss of commercial and game species.2. Public healthShellfish contaminated with Gymnodinium breve cells or the heat stable toxin canproduce neurotoxic shellfish poisoning (NSP) in people who consume raw or cookedmeat. No paralysis occurs with NSP, but tingling of the skin (paresthesia), nausea,vomiting and some loss of voluntary muscle control (ataxia) are major symptomsoccurring within the first three hours (Abdelghani, 1994). Contact dermatitis and/orconjunctivitus may occur in people immersed in water containing brevetoxin (Hemmert,1975). An aerosol of either toxin-laced cell fragments or salt crystals released in surfzones can cause respiratory, skin and mucus membrane irritation, but the symptomscease with no lasting effects once victims leave the area (Hemmert, 1975; Steidingerand Vargo, 1988). The temporary and mild effects of the aerosol toxin are fortunatesince Pierce et al. (1990) determined that laboratory culture concentrations of G. breve73

could give rise to toxins enriched by 5 to 50 times in the aerosol relative to the culture.Though no deaths have yet been attributed to NSP (Shumway, 1990), people shouldnot consume shellfish exposed to a G. breve bloom until reliable tests are conducted toensure that the meat is no longer contaminated; this typically means a wait of one totwo months after cessation of the bloom (Steidinger and Ingle, 1972).Regarding brevetoxin itself, Baden and Thomas (1989) examined severaldifferent clones of G. breve and found significant variability in toxin content between G.breve populations experiencing different environmental conditions. Baden (pers.comm.) states that G. breve is very adept at performing the simple metabolicmodifications that create variability in the toxin profile, and one may presume that thevariability is due to different metabolic states within the organism. One should not,therefore, rule out the possibility that toxins from monoclonal G. breve populations, ifsuch exist, could exhibit differential toxicity to marine animals and humans during abloom depending on the bloom environment. Also, the 1990 studies by Pierce et al.and Roszell et al. revealed that six or more possible toxin profiles appear individually orin combination at different times in the life of a population, whether from examination ofa monoclonal culture or a natural population. Taken together, these findings mayindicate that one or more clones may exist in any given G. breve bloom population;regardless of the clonal constitution, a bloom may produce, as elements age within thepopulation, a suite of toxins that varies in (1) the composition of toxic fractions, (2) theoverall quantity of toxin released at any given point and/or (3) potency. The publichealth implications of these possibilities should be noted. Apparently no public healthrisks have yet been associated with the toxin of Alexandrium monilata.3. Threats to endangered wildlifeWhereas red tide blooms may be detrimental to a variety of endangeredspecies, very little documentation exists for adverse affects on, for example, marinemammals and sea turtles. The most likely and serious threat from red tide to suchspecies in South Texas concerns the whooping crane.The Aransas National Wildlife Refuge reported an overwintering population of133 adult and 8 juvenile whooping cranes for early 1995. Given such low numbers, aGymnodinium breve outbreak could be catastrophic for the entire flock (Tom Stehn,pers. comm.). The G. breve red tide of 1986-87 in South Texas came very close toinfiltrating whooping crane critical habitat in the Aransas National Wildlife Refuge inthe fall of 1986. Because clams, swallowed whole, comprise a small part of awhooping crane's diet in fall and early winter, brevetoxin could possibly sicken or killany cranes consuming contaminated clams. Scaup and cormorants have been knownto perish from exposure to brevetoxin in Florida, so the potential threat to the smallpopulation of endangered whooping cranes in South Texas calls for careful futuremonitoring (Stehn, 1987).4. Ecosystem74

The effects of Gymnodinium breve blooms on the ecosystem may be positive aswell as negative. Both aspects are covered quite well by Steidinger and Vargo (1988),the source for much of what follows.Obviously, negative ecosystem effects begin with marine organism mortality,whether due to toxin or oxygen depletion, whether affecting wild or culturedpopulations of marine life. Oxygen depletion by dense concentrations of either toxic ornon-toxic red tide species can be as detrimental as toxins to fisheries or aquaculture;toxic blooms can cause problems as well for local, national and internationaleconomies, all discussed above.Other ecosystem-level problems include (1) an undefined negative impact fromexcessive nutrient enrichment and bacteria concentrations in waters in whichnumerous fish carcasses decompose and (2) the influence of toxic dinoflagellates onother planktonic organisms. Regarding the latter, Freeberg et al. (1979) used mediumin which G. breve had been grown as a medium for each of 28 phytoplankton speciesin axenic cultures. The medium significantly inhibited growth in 18 species, but itseffect varied within species. The population levels of several diatoms anddinoflagellates and one flagellate barely increased above inoculum concentrations;two dinoflagellate inocula suffered lysis. Toxin extracts totally arrested growth in eightof twelve species (four diatoms and four dinoflagellates), but column chromotographycould not separate the algal inhibition component from the ichthyotoxin. Huntley et al.(1986) used thirteen species of dinoflagellates as possible prey for two species ofcopepods in a large suite of experiments. Results of one experiment included G. breveas one of several dinoflagellates consistently rejected by the copepod Calanuspacificus; ingestion of G. breve cells produced elevated heart rate and loss of motorcontrol in the copepod. The findings of Freeberg et al. (1979) and Huntley et al.(1986) counter the suggestion by Steidinger and Ingle (1972) that G. breve temporarilyaffects inshore and nearshore reef fisheries only, though Steidinger and Ingle (1972)may have had no data on smaller-scale effects.In terms of the positive impacts G. breve has on ecosystems, Steidinger andVargo (1988) point out that G. breve, like all known toxic dinoflagellates, arephotosynthetic primary producers. As such, if a consumer can tolerate the toxin anddigest the cellulose cell wall, G. breve can be a high quality food source. In addition,dinoflagellates in general tend to leak a variable percentage of their daily carbon in theform of amino acids and other complex biochemicals. In bloom proportions,contributions of the dinoflagellate population in terms of food for consumers, dissolvedorganics and the detritus of dead and dying cells must be large. Vargo et al. (1987)offers numerical estimates of various carbon production rates and estimates a highpotential annual carbon input for G. breve blooms off West Florida based on severalsources of data. At the time of publication, however, Steidinger and Vargo (1988)refer to Vargo et al. (1987) and only two other largely speculative studies on thesupposed magnitude of the carbon contribution of any bloom species, but no75

subsequent studies have confirmed the significant carbon contribution postulated forG. breve blooms since 1988 (K. A. Steidinger, pers. comm.). Another possible positiveresult following the negative impact of a toxic bloom is that affected bottomcommunities are kept in states of simplified ecological interactions and increasedsystem efficiency (Steidinger and Vargo, 1988). They cite several sources of supportfor the possibility that periodic fish and invertebrate kills from toxic red tides couldmake for communities less prone to catastrophic collapse from any major perturbationover the long term because their fauna and flora never have time to develop complex,fragile interdependencies. If this is true, the scientific community, the government,fishing industries and the public should best resign themselves to short-term toxic redtide problems in exchange for long-term benefits for affected benthic and reefcommunities and the commercially valuable resources harvested from them.D. Possible causesSteidinger and Vargo (1988) used the terms "initiation," "growth" and"maintenance" to categorize the various factors that produce and promote each stagein the progress of a red tide bloom, and they are used in this section as headings fordiscussing the causative factors for each stage in a Gymnodinium breve bloom. (Theless problematical dinoflagellate Alexandrium monilata has not received as muchattention in terms of published data on the factors prompting it to bloom.) Becausemultiple variables both known and unknown are at work in the marine environmentduring a bloom, any discussion of possible causes remains largely speculative. Thecauses of initiation in particular are problematical, for no proven catalyst has yet beenfound, whether a single variable or suite of variables. As a result, those factorsdiscussed below as possible initiators for G. breve blooms definitely play roles ingrowth and maintenance as well (Rounsefell and Nelson, 1966; Steidinger andHaddad, 1981).1. InitiationIn 1958, Collier suggested that a complex of biological factors causes a red tidebloom and that biologically active organic compounds are important to G. breve,including vitamin B12 and organic chelators, of which the latter can be supplemented orreplaced by sulfides that commonly occur in West Florida estuaries.On a more basic level, salinity is a principal factor in the initiation andsubsequent progress of a G. breve bloom. Aldrich and Wilson (1960) determined thatthe optimal salinity range for axenic cultures of G. breve was from 27 to 37 ppt. Someorganisms survived salinities as low as 22.5 and as high as 46.0 ppt for ten weeks, butthe authors concluded that typical Gulf of Mexico salinities should not imposerestrictions on the growth of this dinoflagellate, though water with salinities of 24 ppt orless should (see also Tester and Fowler, 1990). This low-salinity limitation helpsexplain why G. breve blooms commonly occur in oceanic rather than estuarine waters.76

Along with favorable salinity levels, sufficient light and an adequate carbonsource like carbon dioxide are necessary for any photosynthetic organism. Aldrich(1962) noted a correlation between red tide outbreaks involving Gymnodinium breve onthe Florida Gulf coast and extended periods of heavy rainfall and subsequent organicinput to the sea from river discharge. After unsuccessfully testing a multitude oforganic substances as potential direct energy sources and discovering that theorganism did not grow in the dark in spite of growth additives, he determined that G.breve was not heterotrophic and that sunlight and carbon dioxide were its principalgrowth requirements. He suggested that vitamins, trace metals and chelators fromFlorida river waters may facilitate photoautotrophy and thus bloom formation in G.breve (cf. Collier, 1958) and should be studied further.Ten years later, Steidinger and Ingle (1972) included in their summary ofinformation on G. breve red tides the facts that pollution does not catalyze blooms inFlorida and that dinoflagellate blooms may initiate from seed populations well offshore.Steidinger (1975b) postulated that the offshore seed populations could be either restingpelagic cells or benthic resting cysts (hypnozygotes) from which blooms could initiateand be transported inshore with the aid of physical factors. For instance, Roberts(1979) confirmed that, in 1976, surface concentrations of G. breve increased graduallyoffshore and were then transported inshore due to winds and currents. Initiation inWest Florida, therefore, may well be an offshore phenomenon that accelerates whenand if transport to depth and toward shore concentrates red tide cells in the photiczones of shallow waters (Seliger et al.,1979). That a process similar to West Floridaoccurs for the initiation of blooms off South Texas is quite possible, particularly giventhe prevailing onshore winds in the western Gulf of Mexico.Temperature is another likely significant factor, supported in part by theapparently strong correlation between surface water temperature patterns and majorbloom initiation reported by Baldridge (1975), who claimed that simple indicatorpatterns of water temperatures from mid-January to early April could predict red tideoutbreaks twelve months in advance near Tampa Bay, Florida. He stated that suchpatterns had already shown strong correlation with five major red tides between 1957and 1974 at Egmont Key, Florida, but had no desire to claim cause-effect dependencynor to diminish the importance of other environmental conditions favoring bloominitiation. His claim of the strong predictive power of certain surface temperaturepatterns, however, has not been substantiated since 1974 (K. A. Steidinger, pers.comm.). Though Baldridge's predictive model may not be acceptable, a necessarytemperature range may still be required for initiation. Rounsefell and Nelson (1966)cite results of studies that examined temperature effects on G. breve which, whencombined, defined the survival range from 7 o -32 o C, the range of possible growth from

excystment and cited other studies on different dinoflagellate species that had reportedidentical results with temperature increases.Walker (1982) has confirmed the potential for G. breve cells to formhypnozygotes as part of their sexual cycle, but hypnozygotes have not been found onthe West Florida shelf to date. The Florida program established to look for and mapoffshore "seed beds" was canceled, and hypnozygotes have not yet been induced toform in culture (K. A. Steidinger, pers. comm.). Haddad and Carder (1979) proposethat if seed beds of G. breve hypnozygotes exist on the shelf, the cysts themselves maybe carried in suspension to depths shallower than 40 meters when the Loop Currentintrudes into shelf waters and may encounter conditions conducive to excystment andgrowth, raising the possibility of inshore initiation as well as the previouslysubstantiated offshore process (Steidinger, 1975b; Roberts, 1979; Seliger et al.,1979).Haddad and Carder (1979) cite numerous instances of deep Loop Current and EasternGulf Water (EGW) intrusion onto the shelf that coincided with G. breve blooms off WestFlorida and describe a 1977 Florida bloom that occurred simultaneously with EGWupwelling nearshore. They suggest that some conditions favorable for initiation andsubsequent blooms of G. breve include the decreased temperatures of the LoopCurrent and EGW combined with the increased light availability and increased nutrientsof the nearshore shelf. Finally, Florida blooms need not arise from excystment ofhypnozygotes, for Steidinger (1975a) reports the perennial presence of motile forms ofunknown ploidy of G. breve at less than 1000 cells/liter in the same area of the WestFlorida shelf as the potential seed beds. Such background concentrations could alsobe responsible for the initiation of some blooms.2. GrowthAs early as 1958, Collier suggested that G. breve may produce an organicsubstance that indirectly conditions the water for its own growth in addition to makingpossible use of biologically active organic compounds, vitamin B12, sulfides andorganic chelators. Since red tide outbreaks involving G. breve on the Florida Gulf coastwere correlated with extended periods of heavy rainfall and subsequent organic inputto the sea from river discharge, Aldrich (1962) suggested that vitamins, trace metalsand chelators from river waters may facilitate photoautotrophy and thus bloomformation (i. e., growth) in G. breve and should be studied further. Collier et al. (1969)expanded Collier's 1958 study of organic and inorganic chemicals to determine thatchelated metals (e. g., EDTA-Fe), sulfide, nitrogen, phosphorus and vitamins canpositively influence the growth of G. breve. In a review, Steidinger (1975a) definedsupport for the growth of G. breve in terms of favorable levels of nutrients, growthfactors, temperature and salinity. From available data, she characterized G. breveblooms, however, as gradual increases in motile cells, not sudden increases in celldivision rates. Steidinger and Vargo (1988) cite thesis research that determined lightsaturateddivision rates in G. breve from 0.1 to 0.5/day, comparable to what isconsidered a "normal" dinoflagellate division rate of < 1.0/day. If a normal doublingrate is the rule, then immense G. breve blooms are not explosive episodes of asexual78

eproduction, but even division rates of 0.5/day can produce in eight days aconcentration of 250,000 cells/liter from an initial density of 20,000/liter (Roberts,1979). Densities on the order of 10 6 /liter, however, are best attributed to physicalconcentrating factors, as discussed below.3. Maintenance/TransportBloom maintenance may be defined as the persistent presence of a bloom atconcentrations above background levels. With support from numerous theoreticaltreatments of the behavior of semi-buoyant particles, a term that also describesdinoflagellates, Collier (1958) explained that, whereas a complex of biological factorsapparently prompt a red tide bloom, physical factors such as water mass convergence,wind-driven currents and convection cells cause its mechanical concentration, astatement reiterated by Steidinger and Ingle (1972), Steidinger (1975a), Roberts (1979)and Seliger et al. (1979) (who include tidal influences). G. breve is known for itsinedibility to grazers (Huntley et al., 1986), a definite advantage for maintenance.Huntley et al. (1986) add that, not only do noxious dinoflagellate species such as G.breve gain an interspecific competitive advantage in survival over edible phytoplankton,they also seem far more likely to be able to maintain bloom proportions in spite ofzooplankton grazers when other factors are favorable. Several other factors alsocontribute to the maintenance of high densities of G. breve, including migration of themotile cells (Steidinger, 1975a; Steidinger and Vargo, 1988) and allelopathicsubstances released by G. breve that inhibit the growth of other phytoplankton species(Steidinger and Vargo, 1988) and may aid its own growth (Steidinger, 1983).4. DeclineIt is important to note that the same meteorologic and hydrologic forces thatconcentrate a red tide bloom can disperse it as well (Steidinger, 1983). Steidinger andVargo (1988) list the many other ways besides advection that may diminish andterminate any algal bloom: benthic filter feeders, cell death, grazing, life cycle changes,nutrient limitation and parasitism. To this list one may add sinking and toxic naturalchemicals, the latter due to Collier's (1958) observation that copper levels in somecoastal waters of West Florida were clearly toxic to G. breve. Astronomical factors mayhelp explain the tendency for blooms to be seasonal. Aldrich (1962) noted that G.breve did not grow in the dark in spite of growth-stimulating additives; the decreasingtemperatures and photoperiod of the winter months seem to reduce or prevent thepersistence or initiation of toxic blooms (note the trend of a winter decline seen in Fig.1). Yet atypical winter weather patterns have made exceptions to this general trend,and in areas such as South Texas, mild winter weather and longer photoperiodsrelative to higher latitudes may have little preventive effect.X. Available dataA. Causative species79

1. Gymnodinium breveG. breve was positively identified as the cause of the major red tide blooms of1955 and 1986 as well as the 1990-91 bloom within the Brownsville Ship Channel.One may reasonably assume that the bloom of 1935 was due to G. breve based onreports of respiratory irritation. The cause of the 1974 red tide remains uncertain,though anything other than G. breve would be surprising.2. Alexandrium monilataIt seems very likely that the red tides in Offats Bayou in the 1930s-40s andperhaps earlier (Connell and Cross, 1950) were caused by the chain-forming, armoreddinoflagellate A. monilata, but confirmation of the species in the bayou did not comeuntil 1952 (Howell, 1953). A. monilata was identified in the East Lagoon of GalvestonIsland in the 1960s (Ray and Aldrich, 1967) and was the cause of two blooms offshoreof Galveston in 1971 and 1972 (Wardle et al., 1975). Since then, A. monilata bloomshave only occurred farther south on the Texas coast, with two documented cases in theViola Turning Basin of the Corpus Christi Inner Harbor in 1972 and 1975 (Jensen andBowman, 1975). There are yet unsubstantiated reports of similar blooms in theBrownsville ship channel in 1988 (Dr. Terry Allison, pers. comm).B. Cell concentrations/other biomass estimatesDuring the 1990-91 G. breve bloom in Brownsville, Tony Reisinger, MarineExtension Agent for Cameron County, collected water samples near the surface at onesite in the turning basin of the ship channel from 4 December 1990 to 23 February1991, noting G. breve concentrations along with salinity and surface temperature(Figure 2).35300000Salinity (ppt) and Surface WaterTemperature (Celsius)30252015105TemperatureSalinityCells/ml25000020000015000010000050000G. breve cells/ml0012/1/9012/5/9012/9/9012/13/9012/17/9012/21/9012/25/9012/29/901/2/911/6/911/10/91Figure 2. G. breve concentrations, salinity and surface temperature overtime at one station in the Brownsville Ship Channel Turning Basin(Unpublished data courtesy of T. Reisinger.)1/14/911/18/911/22/911/26/911/30/912/3/912/7/912/11/912/15/912/19/912/23/9180

Though the data in Figure 2 appear to reflect some influence by salinity andtemperature on cell concentration (determined by hemacytometer), the association isnot significant (p = 0.23 from multiple regression), a fact not surprising with knowledgeof the concentrating effect of winds and currents. For example, the lowest temperaturereading in Figure 2, 6 o C on 31 December, was due to a strong cold front producingnortherly winds, a wind direction quite contrary to the typical southeasterly winds on theSouth Texas Gulf Coast at that time of year. Northerly winds rather than thetemperature decrease most likely reduced cell concentrations in the turning basin, themost distal part of the Brownsville Inner Harbor, from the incredibly high numbers on 30December which were attributed to the concentrating effects of typical winds andcurrents (T. Reisinger, pers. comm.). The 1990-91 G. breve bloom in Brownsvilleseems odd relative to the normal offshore initiation and growth of conspecific blooms inWest Florida and Texas, as does the small G. breve bloom that occurred on 8 January1987 in Corpus Christi Bay, about two months after the massive 1986 event(Trebatoski, 1988). Viable cells may have remained in the Corpus Christi Bay systemto produce that brief but dense bloom, but the 1986 bloom may well have seededBrownsville's ship channel with hypnozygotes that excysted in response to unknownstimulating factors in the channel prior to the initial fish kill in late November of 1990.This hypothesis could only be confirmed by discovery of cysts in ship channelsediments, if any cysts remain, for the 1990-91 bloom at times occupied much if not allof the ship channel and the associated Lake San Martin, where a sample with 30,000cells/ml was taken on 13 December 1990 (T. Reisinger, pers. comm.).The 1986 G. breve bloom did penetrate well into the inland waterways of SouthTexas, passing through such entrances as the ship channel at Port Aransas, wherewater samples were taken at the pier laboratory of the University of Texas MarineScience Institute (Figure 3; Buskey, unpublished data).7.06.05.04.03.02.01.00.027-Sep29-Sep1-Oct3-OctLog G. breve cells/ml5-Oct7-Oct9-Oct11-Oct13-Oct15-Oct17-Oct19-Oct21-Oct23-Oct25-OctFigure 3. G. breve concentrations as means or singlecounts from water sampled at the UTMSI Pier Lab, PortAransas in 1986. Error bars are + log 10 standard errors.81

C. Spatial and temporal bloom distributionsOnly data from the 1986 G. breve bloom provide enough information on spatialand temporal distribution of any major bloom. The extent of the 1986 bloom can bedepicted in terms of coastal Texas counties with dinoflagellates present in theirnearshore waters in concentrations detectable by aerial survey (Table 2).Table 2. Confirmation of G. breve presence by twelve aerial surveys of the nearshore waters and bays ofcoastal Texas counties from Galveston southward to the Mexican border (excluding Jackson County) inthe fall of 1986.* "X" indicates confirmed observation; "?" indicates unconfirmed presence north ofMatagorda Bay. (Data from Trebatoski, 1988.)GalvestonBrazoriaSEP4SEP9SEP10SEP12SEP14Matagorda X ? X X X X X X X X X XCalhoun X X X X X X X X X X X XRefugio X X X X X X X X X XAransas X X X X X X X X X XSan Patricio X X X X XNueces X XKleberg X XKenedy X XWillacyCameronSEP16*Notes: (1) This G. breve red tide was first observed near Galveston Island on 27 August 1986 but was no longervisible to aerial surveys north of the border between Matagorda and Brazoria Counties by 4 September. (2) Aerialsurveys on 23 and 24 October 1986 reported no visible red tide along Texas shores.Of special interest is the fact that no red tide was visible by air only one week after themaximum extent of G. breve presence along the Texas coast. Spatial distributions mayvary widely, to some degree depending on whether the bloom is inshore or offshore.Temporal distributions are also widely variable and may change by many orders ofmagnitude in relatively short periods.D. Fish killsAn estimated 2 million pounds of dead fish resulted from the 1935 red tide, forwhich the species responsible was likely G. breve (Snider, 1987). A widelydocumented fish kill, again apparently due to G. breve, littered the Gulf coast from apoint 17 miles north of Port Isabel, Texas to a 120-mile stretch in the Mexican state ofTamaulipas in September of 1955. The 1974 red tide well offshore of Brownsville andMatamoros caused a massive fish kill that eventually littered Mexican beaches, but noestimates of the extent of fish mortality are known. The bulk of available data on fishmortality is associated with the G. breve red tide of 1986; Trebatoski (1988) includes anSEP22SEP26SEP29OCT10OCT14OCT16XX82

extensive list of all fish species that suffered mortality as identified by the Texas Parksand Wildlife Department. Table 3 summarizes the minimum numbers of individualskilled for seven common fish species of recreational or commercial importance (slightlymodified from Texas Parks and Wildlife Department, 1986).Table 3. Minimum estimates of fish killed by the G. breve red tide of 1986 in inshore and offshoreTexas waters. (Data from Texas Parks and Wildlife Department, 1986.)Selected SpeciesArea Red Spotted Southern Atlantic Black Gulf StripedDrum Seatrout Flounder Croaker Drum Menhaden Mullet TotalBays 15,800 41,300 38,200 70,000 2,100 480,000 790,000 1,437,400Gulf 27,100 39,500 2,800 172,000 1,700 2,770,000 3,240,000 6,253,100Total 42,900 80,800 41,000 242,000 3,800 3,250,000 4,030,000 7,690,500E. Shellfish bedsAmong many other duties, the Division of Seafood Safety in the TexasDepartment of Health is responsible for determining acceptable levels of red tidecontamination in shellfish meats and closing shellfish beds when meats contain abovethresholdlevels of toxin. Since 1986, South Texas bays and inshore bodies of water,including two of those in the Corpus Christi Bay National Estuary region, have facedclosure for varied lengths of time as indicated in Table 4. Because shellfish areprincipally harvested in waters north of Port Aransas and those are the sites mostfrequently sampled by the Texas Department of Health (G. Heideman, pers. comm.),only those bodies of water from Aransas Bay and northward are listed in Table 4.Notice the duration of some closures and the dates of those shellfish beds that wereclosed well after the 1986 G. breve red tide. Continued shellfish contamination after the1986 bloom and the dates of later incidents of contamination imply that G. breve eitherblooms with a frequency and/or persists to degrees only poorly realized at present (cf.Table 1 and associated text in Section II. A.).83

Table 4. Dates of closure due to red tide (G. breve) contamination and subsequent reopening of selectedSouth Texas shellfish harvesting areas from 1986-1990 by order of the Texas Department of Health.(Data courtesy of G. Heideman, Texas Department of Health.)Area Status 1986 1987 1988 1989 1990East Matagorda CLOSED 6 SepBay REOPENED 4 DecMatagorda Bay CLOSED 6 SepREOPENED2 DecTres Palacios CLOSED 6 SepBay REOPENED 20 FebCarancahua CLOSED 6 SepBay REOPENED 20 FebLavaca Bay CLOSED 6 SepREOPENED 20 Feb (in part) 13 Feb (all)Powderhorn CLOSED 6 SepLake REOPENED 15 OctEspiritu Santo CLOSED 6 SepBay REOPENED 15 OctSan Antonio Bay CLOSED 6 SepREOPENED 14 DecMesquite Bay CLOSED 6 SepREOPENED20 FebCopano Bay* CLOSED 6 Sep 25 AugREOPENED 20 Feb 2 SepAransas Bay* CLOSED 6 Sep 10 Jan 25 AugREOPENED 1 Jan; 20 Feb 2 Sep*These bays are included in the Corpus Christi Bay National Estuary region.F. Gulf of Mexico circulationElliot (1982) presented convincing evidence of one or more anti-cyclonic eddiesor gyres that form and depart annually from the Gulf Stream's Loop Current west ofFlorida to migrate westward, maintaining some structural and thermal integrity for aslong as a year. Hofmann and Worley (1986) later substantiated the existence of thesegyres, and satellite data have shown that the Loop Current occasionally intrudes ontothe West Florida Shelf (P. A. Tester, pers. comm.) where G. breve blooms typicallyinitiate (Steidinger, 1975b). Already documented is the apparent transport of G. breveseed populations from the West Florida Shelf in the Loop Current around the Floridapeninsula to the shores of North Carolina via the Gulf Stream, the cause of a novelbloom there in late 1987 (Tester et al., 1991).Should entrainment of seed populations occur in the Loop Current followed bygyre formation, subsequent eddy transport could carry G. breve populations to the GulfCoast of Texas and Mexico. Once in the vicinity of the Texas-Mexico Shelf, surface84

circulation patterns could work in concert with the decaying anti-cyclonic gyre tointegrate gyre waters and their plankton into the westward coastal current described byBarron and Vastano (1994). The westward coastal current results from the inferredexistence of a cyclonic gyre normally present from September through May, thesouthernmost extent of which marks a convergence of coastal currents driven by theprevailing southerly to southeasterly winds in the Western Gulf of Mexico (Cochraneand Kelly, 1986; Hofmann and Worley, 1986). The prevailing winds, counteredsomewhat in winter by the northerly winds of cold fronts, produce a convergence ofcoastal flow patterns at a seasonally variable location somewhere between theMatagorda Peninsula and Brownsville (Watson and Behrens, 1970; Barron andVastano, 1994). The geopotential anomaly data of Cochrane and Kelly (1986),according to Barron and Vastano (1994), can only describe a very general cycloniccurrent pattern off the Texas-Louisiana Shelf that is subject to significant short-termvariability. That variability, however, does not preclude the possibility that both theSouth Texas coastal flow convergence and the cyclonic gyre on the Texas-LouisianaShelf could bring G. breve populations into nearshore waters as far north as Galveston(the initial site of the 1986 bloom) or along the coast of South Texas and Mexico (as inthe offshore blooms of 1935, 1955 and 1974) whether G. breve is resident in theoffshore waters of the Texas shelf (Geesey and Tester, 1993) or transported byanticyclonic gyre from the Eastern Gulf. The same coastal current patterns (theconvergence and cyclonic gyre) could facilitate immigration of A. monilata populationsfrom the north central Gulf, as described below.XI. Potential status of red tide species in Texas coastal watersAny potential means of controlling Gymnodinium breve (and probablyAlexandrium monilata) blooms that involves the destruction of the cells may do more toexacerbate rather than prevent or diminish the toxic effect of the bloom. For example, acytolytic chemical extracted from a blue-green alga together with an effective, non-toxicdelivery medium could be used to reduce dense concentrations of G. breve (Eng-Wilmot et al., 1979a,b) but would prompt the release of brevetoxin upon lysis. Thepotential status of G. breve and A. monilata as problematic bloom species along theSouth Texas Gulf Coast, therefore, may not be subject to human control except viareduction of anthropogenic eutrophication of inshore and coastal waters, if excessnutrients actually promote toxic dinoflagellate blooms (Hallegraeff, 1993).Regarding the potential status of A. monilata, Howell's (1953) work on Florida'seast coast predated documentation of A. monilata blooms and associated fish kills onthe west coast of Florida by almost twenty years (Williams and Ingle, 1972), though thefirst detection of this dinoflagellate south of Fort Myers, Florida actually occurred inearly August of 1966. A fish kill soon followed, and from the first report of mortality on16 August until the end of that month, high cell counts discolored the waters andcontinued to kill fish between Tampa Bay and Cape Romano. A. monilataconcentrations finally fell to low levels by late September. Williams and Ingle (1972)pointed out that records of A. monilata up to that time had been known only from85

estuaries such as those in the Chesapeake Bay, on the coast of Venezuela and in theGalveston, Texas area. They also found high concentrations from less than a mile to42 miles offshore of West Florida in late 1966, with a maximum of slightly over 1.3million cells/l at a site 400 meters out from the barrier islands near Sarasota on 21August. The possibility exists, therefore, for offshore blooms of this dinoflagellate inSouth Texas as well.Because A. monilata does not contaminate shellfish and may have only a slightimpact on finfish depending on the location, small blooms may be frequent in SouthTexas, escaping offical attention and documentation. Seed populations may bearriving from the north central Gulf of Mexico, also, for A. monilata cells from awidespread bloom in September of 1980 off Louisiana not only occupied numerousbayous and sounds but were found in large numbers in water samples from west of theMississippi River (Perry, 1980), exposing them to possible transport to Texas in thewestward coastal current resulting from the river's outflow. Several A. monilata bloomsoccurred at about that time in the north central Gulf, one in August 1979, the onementioned above and another in July 1981 (Perry and McLelland, 1981). Thoseoutbreaks showed some correlation with lowered salinity which, if causal, may promptblooms along the Texas coast should a hurricane or tropical storm decrease salinitiesin inshore and nearshore waters, perhaps especially in areas that have sufferedprevious A. monilata blooms.Discussion of the postulated trans-Gulf movement of G. breve populations inLoop Current gyres, if it occurs, should not obscure the potential for endemicpopulations of the dinoflagellate in the offshore waters of Texas to seed nearshoreblooms. Geesey and Tester (1993) report that G. breve is found throughout the Gulf ofMexico, but, until their study, its cell density in nearshore and offshore waters ofvarious depths was largely unknown. For twelve months beginning in March of 1990,NOAA vessels sampled 61 stations throughout the Gulf of Mexico from depths of 0 to>150 m. The density of G. breve in shallow, well-mixed waters was constant, but indeeper waters with a thermocline, the dinoflagellate was more abundant near thesurface. Concentrations in central Gulf waters remained at 100 cells/ml,including two stations offshore of Galveston, Texas. Concentrations from 1-100cells/ml occurred at coastal stations between St. Joseph Island and Matagorda Island.With the well-documented westward coastal current along the Texas coast (Barron andVastano, 1994), concentrations of G. breve at >100 cells/ml could theoretically befound anywhere along the coastline included in the Corpus Christi Bay NationalEstuary region. The low frequency of major offshore blooms implies that conditionsfavorable for initiation do not commonly occur in South Texas waters, but the frequentdetection of brevetoxin-contaminated shellfish and the closures of shellfish beds by theTexas Department of Health imply that red tide blooms often occur without beingotherwise documented (G. Heideman, pers. comm.; see Tables 1 and 4). Similarly,Steidinger's (1975) statement that 75% of G. breve blooms that begin offshore of WestFlorida never make it to nearshore waters may also apply to offshore waters of South86

Texas, a possibility that may only be substantiated if toxic dinoflagellates become thefocus of an offshore sampling program.Besides the unknown extent of the negative economic impact of G. breve bloomson the South Texas shellfishing industry, not to mention recreational fishing andtourism, the relatively infrequent red tide problems experienced in Texas coastal andinshore waters do not apparently require any changes in current marine policy. Redtide blooms should be understood as naturally occurring events, unless G. breve hasbeen or could be introduced by the discharge of ships ballast water containing viablecells or hypnozygotes (Hallegraeff and Bolch, 1992). Should toxic blooms in Texasincrease in frequency and severity, however, Texas marine policy should definitelychange to provide warning of bloom initiation, expansion and transport and to collectthe data necessary to define the factors involved in each step of a bloom.XII. Identification of data and information gaps1. The most obvious gap is in the lack of consistent data on red tide concentrationsduring and after a bloom (if not also before). This requires regular water sampling ofestablished sites that ideally includes measurement of in situ temperature, salinity andperhaps winds and currents. Samples should then be analyzed with respect tonutrients and biologically active organic compounds as well as cell concentrations.2. Thorough sediment analyses, with the object of looking for hypnozygotes at thebottom of such areas as the turning basins in Corpus Christi Inner Harbor and theBrownsville Ship Channel, would provide useful and novel information on the life cyclesof both A. monilata and G. breve in Texas waters regardless of the results. Similaranalyses of ship's ballast water for cysts or cells in cargo vessels coming from portsknown to have G. breve blooms (such as those on Florida's West Coast) would also beuseful (Hallegraeff and Bolch, 1992).3. Examining future offshore G. breve blooms with continually available satelliteimagery (Gallegos, 1990) and aerial or shipboard means of determining temperature,salinity, nutrients and the bloom's surface coverage would be useful in delineatinginitiation, growth and eddy transport factors. Likewise, conducting regular sampling ofthe coastal current and sites of previous A. monilata blooms would be helpful butperhaps not as high a priority relative to the greater negative impact of G. breveblooms.4. Automatic notification of incidents of shellfish contamination and information transferbetween the Shellfish Sanitation Division of the Texas Department of Health andscientists in both academia and other public agencies who are interested in toxicblooms would greatly facilitate timely work with G. breve whenever concentrations arehigh enough to produce positive toxin bioassays. This notification could be as simple,inexpensive and efficient as one message sent to a standard list of researchers andgovernmental agencies. In turn, any recipient would also be able to notify the87

Department of Health and all other listed recipients of any new blooms. In fact, thebulletin board-style service of the recently established "TexCoast" on the Internet mayserve in this capacity. [For further information on "TexCoast," contact Don Hockaday(hockaday@panam.edu) or Dr. Terry Whitledge (terry@utmsi.zo.utexas.edu).]88

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Elliott, B. A. (1982). Anticyclonic rings in the Gulf of Mexico. Journal of PhysicalOceanography. 12: 1292-1309.Eng-Wilmot, D. L., McCoy, L. F., Jr., Martin, D. F. (1979). Isolation and synergism of ared tide (Gymnodinium breve) cytolytic factor(s) from cultures of Gomphosphaeriaaponina. In: Toxic Dinoflagellate Blooms, Proceedings of the Second InternationalConference on Toxic Dinoflagellate Blooms, Key Biscayne, Florida, Oct. 31-Nov. 5,1978. D. L. Taylor and H. H. Seliger (eds). Elsevier/North-Holland, Inc. p. 355-360.Eng-Wilmot, D. L., Henningsen, B. F., Martin, D. F., Moon, R. E. (1979). Model solventsystems for delivery of compounds cytolytic towards Gymnodinium breve. In: ToxicDinoflagellate Blooms, Proceedings of the Second International Conference on ToxicDinoflagellate Blooms, Key Biscayne, Florida, Oct. 31-Nov. 5, 1978. D. L. Taylor and H.H. Seliger (eds). Elsevier/North-Holland, Inc. p. 361-366.Freeberg, L. R., Marshall, A., Heyl, M. (1979). Interrelationships of Gymnodinium breve(Florida red tide) within the phytoplankton community. In: Toxic Dinoflagellate Blooms,Proceedings of the Second International Conference on Toxic Dinoflagellate Blooms,Key Biscayne, Florida, Oct. 31-Nov. 5, 1978. D. L. Taylor and H. H. Seliger (eds).Elsevier/North-Holland, Inc. p. 139-144.Gallegos, S. (1990). Evaluation of the potential of the NOAA-n AVHRR reflective datain oceanography (dissertation). Department of Oceanography, Texas A & M University,College Station, TX, USA. 189 pp.Gates, J. A., Wilson, W. B. (1960). The toxicity of Gonyaulax monilata Howell to Mugilcephalus. Limnol. Oceanogr. 5 (2): 171-174.Geesey, M., Tester, P. A. (1993). Gymnodinium breve: ubiquitous in Gulf of Mexicowaters? In: Toxic Phytoplankton Blooms in the Sea, Proceedings of the FifthInternational Conference on Toxic Marine Phytoplankton. T. J. Smayda and Y. Shimizu(eds). Elsevier p. 251-255.Gunter, G. (1951). Mass mortality and dinoflagellate blooms in the Gulf of Mexico.Science 113:250-251.Haddad, K. D., Carder K. L. (1979). Oceanic intrusion: one possible initiationmechanism of red tide blooms on the west coast of Florida. In: Toxic DinoflagellateBlooms, Proceedings of the Second International Conference on Toxic DinoflagellateBlooms, Key Biscayne, Florida, Oct. 31-Nov. 5, 1978. D. L. Taylor and H. H. Seliger(eds). Elsevier/North-Holland, Inc. p. 269-274.Hallegraeff, G. M. (1993). A review of harmful algal blooms and their apparent globalincrease. Phycologia 32 (2): 79-99.90

Hemmert, W. H. (1975). The public health implications of Gymnodinium breve redtides, a review of the literature and recent events. In : Proceedings of The FirstInternational Conference on Toxic Dinoflagellate Blooms. V. R. LoCicero (ed). TheMassachusetts Science and Technology Foundation, Wakefield, MA. p. 489-497.Hofmann, E. E., Worley, S. J. (1986). An investigation of the circulation of the Gulf ofMexico. Journal of Geophysical Research. 91(C12): 14,221-14.236.Howell, J. F. (1953). Gonyaulax monilata, sp. nov., the causative dinoflagellate of a redtide on the east coast of Florida in August-September, 1951. Transactions of theAmerican Microscopical Society. 72: 153-156.Huntley, M., Sykes, P., Rohan, S., Marin, V. (1986). Chemically-mediated rejection ofdinoflagellate prey by the copepods Calanus pacificus and Paracalanus parvus:mechanism, occurrence and significance. Marine Ecology Progress Series. 28: 105-120.Jensen, A. C. (1975). The economic halo of a red tide. In: Proceedings of The FirstInternational Conference on Toxic Dinoflagellate Blooms. V. R. LoCicero (ed). TheMassachusetts Science and Technology Foundation, Wakefield, MA. p. 507-516.Jensen, D. A., Bowman, J. (1975). On the occurrence of the "red tide" Gonyaulaxmonilata in the Corpus Christi Inner Harbor (July-September 1975). Texas WaterQuality Board, District 12. 20 pp.Joyce, E. A., Jr., Roberts, B. S. (1975). Florida Department of Natural Resources RedTide Research Program. In: Proceedings of The First International Conference onToxic Dinoflagellate Blooms. V. R. LoCicero (ed). The Massachusetts Science andTechnology Foundation, Wakefield, MA. p. 95-103.Lund, E. J. (1936). Some facts relating to the occurrences of dead and dying fish on theTexas coast during June, July, and August, 1935 In: Annual Report of the Texas Game,Fish and Oyster Commission, 1934-35. Texas Game, Fish and Oyster Commission. p.47-50.Marvin, K. T. (1965). Operation and maintenance of salt-water laboratories. In: FisheryResearch: Biological Laboratory, Galveston, Fiscal Year 1964, Circular 230. UnitedStates Department of the Interior, Fish and Wildlife Service, Bureau of CommercialFisheries. p. 84-86.Perry, H.M. (1980). Dinoflagellate blooms occur off Lousiana. Coastal OceanogClimatol News 3(1): 3.91

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Rounsefell, G. A., Nelson, W. R. (1966). Red-tide research summarized to 1964including an annotated bibliography. United States Fish and Wildlife Service SpecialScientific Report, Fisheries No. 535, Washington, D. C. 85 pp.Roszell, L. E., Schulman, L. S., Baden, D. G. (1990). Toxin profiles are dependent ongrowth stages in cultured Ptychodiscus brevis. Toxic Marine Phytoplankton,Proceedings of the Fourth International Conference on Toxic Marine Phytoplankton. E.Granéli, B. Sundström, L. Edler and D. M. Anderson (eds). Elsevier. p. 403-406.Seliger, H. H., Tyler, M. A., McKinley, K. R. (1979). Phytoplankton distributions and redtides resulting from frontal circulation patterns. In: Toxic Dinoflagellate Blooms,Proceedings of the Second International Conference on Toxic Dinoflagellate Blooms,Key Biscayne, Florida, Oct. 31-Nov. 5, 1978. D. L. Taylor and H. H. Seliger (eds).Elsevier/North-Holland, Inc. p. 239-248.Shumway, S. E. (1990). A review of the effects of algal blooms on shellfish andaquaculture. Journal of the World Aquaculture Society. 21 (2): 65-104.Sievers, A. M. (1969). Comparative toxicity of Gonyaulax monilata and Gymnodiniumbreve to annelids, crustaceans, molluscs and a fish. Journal of Protozoology 16 (3):401-404.Snider, R. (ed.). (1987). Red tide in Texas: an explanation of the phenomenon. MarineInformation Service, Texas A&M Sea Grant College Program. 4 pp.Stehn, T. (1987). Whooping cranes during the 1986-1987 winter. Aransas NationalWildlife Refuge, U. S. Fish and Wildlife Service. 45 pp.Steidinger, K. A. (1975a). Basic factors influencing red tides. In: Proceedings of theFirst International Conference on Toxic Dinoflagellate Blooms. V. R. LoCicero (ed). TheMassachusetts Science and Technology Foundation, Wakefield, MA. p. 153-162.Steidinger, K. A. (1975b). Implications of dinoflagellate life cycles on initiation ofGymnodinium breve red tides. Environmental Letters. 9 (2): 129-139.Steidinger, K. A. (1979). Collection, enumeration and identification of free-living marinedinoflagellates. In: Toxic Dinoflagellate Blooms, Proceedings of the SecondInternational Conference on Toxic Dinoflagellate Blooms, Key Biscayne, Florida, Oct.31-Nov. 5, 1978. D. L. Taylor and H. H. Seliger (eds). Elsevier/North-Holland, Inc. p.435-442.Steidinger, K. A. (1983). A re-evaluation of toxic dinoflagellate biology and ecology In:Progress in Phycological Research, Vol. 2. Round and Chapman (eds). ElsevierScience Publishers B. V. p.147-188.93

Steidinger, K. A., Ingle, R. M. (1972). Observations on the 1971 summer red tide inTampa Bay, Florida. Environmental Letters 3 (4): 271-278.Steidinger, K. A., Joyce, E. A., Jr. (1973). Educational Series No. 17: Florida RedTides. State of Florida Department of Natural Resources, St. Petersburg. 26 pp.Steidinger, K. A., Vargo, G. A. (1988). Marine dinoflagellate blooms: dynamics andimpacts. In: Algae and Human Affairs. C. A. Lembi and J. R. Waaland (eds). CambridgeUniversity Press, New York, NY. p. 373-401.Tester, P.A., Fowler, P.K. (1990). Brevetoxin contamination of Mercenaria mercenariaand Crassostrea virginica: a management issue. In: Toxic Marine Phytoplankton,Proceedings of the Fourth International Conference on Toxic Marine Phytoplankton E.Granéli, B. Sundström, L. Edler and D. M. Anderson (eds). Elsevier. p.499-503.Tester, P. A., Stumpf, R. P., Vukovich, F. M., Fowler, P. K., Turner, J. T. (1991). Anexpatriate red tide bloom: transport, distribution, and persistence. Limnol. Oceanogr. 6(5): 1053-1061.Texas Parks and Wildlife Department. (1986). Commission Agenda Item (BriefingSession): Red Tide. 3 pp.Trebatoski, B. (1988). Observations on the 1986-1987 Texas Red Tide (Ptychodiscusbrevis), Report 88-02. Texas Water Commission. 48 pp.Vargo, G. A., Carder, K. L., Gregg, W., Shanley, E., Neil, C., Steidinger, K. A., Haddad,K. D. (1987). The potential contribution of primary production by red tides to the westFlorida shelf ecosystem. Limnol. Oceanogr. 32 (3): 762-767.Walker, L. M. (1982). Evidence for a sexual cycle in the Florida red tide dinoflagellate,Ptychodiscus brevis (= Gymnodinium breve). Transactions of the AmericanMicroscopical Society 101(3): 287-293.Walker, L. M., Steidinger, K. A. (1979). Sexual reproduction in the toxic dinoflagellateGonyaulax monilata. Journal of Phycology 15: 312-315.Wardle, W. J., Ray, S. M., Aldrich, A. S. (1975). Mortality of marine organismsassociated with offshore summer blooms of the toxic dinoflagellate Gonyaulax monilataHowell at Galveston, Texas In: Proceedings of the First International Conference onToxic Dinoflagellate Blooms. V. R. LoCicero (ed). The Massachusetts Science andTechnology Foundation, Wakefield, MA. p. 257-263.Watson, R. L., Behrens, E. W. (1970). Nearshore surface currents, southeastern TexasGulf Coast. Contributions in Marine Science 15: 133-143.94

Williams, J., Ingle, R. M. (1972). Ecological Notes on Gonyaulax monilata(Dinophyceae) Blooms Along the West Coast of Florida. In: Florida Department ofNatural Resources Leaflet Series: Phytoplankton, Part 1 (Dinoflagellates), No. 5.Wilson, W. B., Ray, S. M. (1956). The occurrence of Gymnodinium brevis in thewestern Gulf of Mexico. Ecology 87 (2) :388.95

XIV. Materials and Methods: Unpublished DataKen H. Dutton: Seagrass Density and Biomass.Measurements of total plant biomass were made at 2 to 3 month intervals fromfour replicate samples collected at the two stations with a 9 cm diameter coring device.Samples were thoroughly cleaned of any epiphyte material in the laboratory, separatedinto above-ground and below-ground live biomass (to calculate root:shoot ratios) anddried at 60 o C to a constant weight. Results are expressed as total biomass (g dry wtm -2 ) of all shoot, rhizome and root material collected in each core. Measurements ofleaf elongation rate and shoot production were collected using the leaf-clippingtechnique described in Virnstein 1982. for Halodule wrightii (the leaves of H. wrightii aretoo thin for leaf-tagging techniques). Shoots were clipped about 2 cm above the basalsheath to permit regrowth, and cores were collected from each clipped area to measurenet growth at 3 to 6 week intervals. In the laboratory, the length of the newly formedblades was recorded for individual shoots and all new blade material was pooled fromeach of four replicate cores for determination of shoot production on a dry weight basis.the mean leaf elongation rate for each replicate core sample was based on themeasurement of 20 to 30 blades (Adapted from Dunton 1994).G. Joan Holt: Larval Feeding and SurvivalStudies were carried out in brown tide containing ponds at the GCCA hatchery inCorpus Christi Texas. Feeding studies were carried out in 20 oz soda bottles in whichthe neck had been removed and 3, 8 cm X 5 cm, panels were cut. The resultingopenings were covered with 100 µm nitex mesh nets. For laboratory studies, the bottleswere placed inside 1 liter beakers filled with either 48 µm filtered brown tide water (witha concentration of brown tide cells of 1 million ml -1 or greater) or control sea water(without brown tide). For field studies, the bottles were placed in either a 48 µm meshbag, or a control water filled plastic bag and hung from a floating rack. Five to fifteenlarvae, all the same age, were placed in each bottle, and allowed to acclimate for 1hour prior to food addition. The 5 and 7 day old larvae were fed rotifers at aconcentration of 5 ml -1 . The 14 day old larvae were fed Artemia at a concentration of 3ml -1 . After a one hour feeding time the larvae were removed and gut dissection wasperformed to count the number of prey items consumed.Hatch rates and survival studies in the field were also carried out with thebagged bottles hung from the floating rack. While the laboratory studies wereperformed in 100 ml beakers filled with the test treatments of brown tide water orcontrol seawater. To each treatment a defined number of eggs were added. The eggswere left overnight and the unhatched eggs and dead larvae were removed andcounted to determine hatching rates and day 1 survival rates. Each day of theexperiment the dead larvae were removed and counted to obtain survival rates.Scott A. Holt: Larval Densities.96

Larvae were collected with five replicate ichthyoplankton tows using a 1-m net(500 µm mesh) attached to an epibenthic sled pulled through the lower 1m of the watercolumn. The volume of water filtered for each tow was measured with a mechanicalflowmeter. Samples were preserved in 5% formalin or 70% ethanol. All sciaenids in thesamples were identified to species (except Menticirrhus sp.), enumerated, andmeasured. Larval densities are expressed an number per 1000 m 3 of water (adaptedfrom Holt, et al. 1994).Paul A. Montagna: Benthic Biomass, Abundance, and Diversity.The microfauna were sampled with diver held core tubes with diameters of 6.7cm. The cores were sectioned at the 0-3 cm and 3-10 cm depth intervals. Themeiofauna were sampled with diver held core tubes with diameters of 1.8 cm. Thesecores were sectioned at the 0-1 cm and 1-3 cm depth intervals. Three replicates, takenwithin a 2m radius, of each sample was obtained. Samples were preserved with 5%buffered formalin, sorted, identified and counted. The macrofauna samples were usedto measure biomass. Samples were dried for 24 hr. at 55 o C and weighed. Beforedrying, mollusks were placed in 1N HCl to dissolve the carbonate shells, and washed(adapted from Montagna and Kalke 1992).Dean A. Stockwell: Chlorophyll a.See Chlorophyll a analysis methods from Terry E. Whitledge: Nutrient andHydrographic Conditions.Terry E. Whitledge: Nutrient and Hydrographic Conditions.Samples were collected monthly from 57 stations in upper Laguna Madre andMansfield Pass in lower Laguna Madre. A SeaBird model SBE 19 CTD profiler wasused to obtain salinity and temperature data with respect to depth. Discrete watersamples for salinity by refractometer, nutrients (nitrate, ammonium, nitrite, phosphateand silicate), chlorophyll a and Phaeophytin were collected near the surface by hand,and near the bottom with a Van Dorn style water sampler. The samples were collectedin clean pre- labeled polyethylene bottles and immediately chilled with ice in the dark.Secchi depths were measured on all stations.Nutrient analyses were determined on the chilled samples with a segmented flowautomated chemical analyzer using methods developed for marine and estuarinewaters (Whitledge et al. 1981, 1989) Chlorophyll and phaeopigment measurementswere determined by the fluorometric method (Holm-Hansen et al. 1965), withmodification for 60% acetone: 40% DMSO extraction at 4 o C (Dagg and Whitledge,1991, Stockwell 1989) (adapted from Whitledge 1991).97

XV. Annotated BibliographyTHE ANNOTATED BIBLIOGRAPHY OF THE"BROWN TIDE AND RED TIDE CURRENT STATUS" CONTRACT WITH THECCBNEP[All entries pertain wholly or in part to red or brown tide events or experiments; if a sourceis general, key words will reflect only sections pertinent to brown or red tide.]Author: Abdelghani, A., Hartley, W. R., Esmundo, F. R., and Harris, T. F.Date: 1994Title: Biological and chemical contaminants in the Gulf of Mexico and the potentialimpact on public health: a characterization reportPages: 77 pp.Source: Tulane University School of Public Health and Tropical Medicine, New Orleans,LAKey words: biological contaminant, Gulf of Mexico, public health, biotoxin, red tide,dinoflagellate, bloom, Gymnodinium breve, neurotoxin, neurotoxic shellfishpoisoning (NSP)Summary: A small portion of this unpublished draft report describes briefly and in generalterms the negative effects of Gymnodinium breve red tide on people who ingestcontaminated shellfish or inhale the toxin as an aerosol as well as on othermembers of the marine ecosystem. A list of red tide occurrences in Florida from1975-1991 follows. No cases of NSP have been reported from any state otherthan Florida, and while red tides have occurred in Florida and Texas, none havebeen reported for Alabama, Mississippi or Louisiana.Methods: N/A (Draft report)QA/QC: N/AContact: Dr. Fred KopflerSource Inst.: Not available; contact by phone at (601) 688-2712.Author: Aldrich, D. V.Date: 1962Title: Photoautotrophy in Gymnodinium breve DavisJournal: Science 137(3534):988-990Key words: Gymnodinium breve, photoautotrophy, culture, Florida, red tide, dinoflagellate,light, carbon dioxide, growth, micronutrientsSummary: Since red tide outbreaks involving Gymnodinium breve on the Florida Gulf coastwere correlated with extended periods of heavy rainfall and subsequent organicinput to the sea from river discharge, the author tested a multitude of organicsubstances as potential direct energy sources for G. breve. Light and carbondioxide, however, were the principal growth requirements. No growth occurred inthe dark in spite of additives. It is therefore unlikely that heterotrophy plays alarge role in bloom formation. Vitamins, trace metals and chelators from river98

waters may facilitate photoautotrophy and thus bloom formation in G. breve andshould be studied further.Methods: See text (no divisions).QA/QC: None per se; see text.Contact: David V. AldrichSource Inst.: Bureau of Commercial Fisheries, Biological Laboratory, Galveston, Texas, USAAuthor: Aldrich, D. V., and Wilson, W. B.Date: 1960Title: The effect of salinity on growth of Gymnodinium breve DavisJournal: Biol. Bull. 119:57-64Key words: salinity, growth, Gymnodinium breve, dinoflagellate, bloom, red tide, cultureSummary: Bacteria-free cultures of Gymnodinium breve experienced media with salinitiesranging from 6.3 to 46.0 ppt, growing best between 27 and 37 ppt. Someorganisms survived salinities as low as 22.5 and as high as 46.0 ppt for ten weeks;there was no indication of reduced survival at the extremes of 24.8 and 46.0 ppt.The authors conclude that typical Gulf of Mexico salinities should not imposerestrictions on the growth of this dinoflagellate, though water with salinities of 24ppt or less should.Methods: See "Materials and Methods."QA/QC: None per se; see "Materials and Methods."Contact: David V. AldrichSource Inst.: Biological Laboratory, U. S. Bureau of Commercial Fisheries, Galveston, Texas,USAAuthor: Aldrich, D. V., Ray, S. M., and Wilson, W. B.Date: 1967Title: Gonyaulax monilata: population growth and development of toxicity in culturesJournal: J. Protozool. 14(4):636-639Key words: Gonyaulax monilata, growth, toxicity, culture, dinoflagellate, Lebistes reticulatus,autolysisSummary: The chain-forming dinoflagellate Gonyaulax monilata [now known asAlexandrium monilata] was cultured in three 8-liter and four 12-liter containers,the population densities of which were estimated weekly for 17 weeks.Populations peaked at 3-5 weeks, declined from 6-10 weeks and usually stabilizedthereafter until the final week. Populations that showed more rapid increase hadthe greatest proportion of long chains, a possible growth index, and peak toxicity(gauged by the toxic effect on the guppy, Lebistes reticulatus) occurred only whencultures had been in decline for a month, indicating autolytic release of toxin, andhad no relationship to estimated cell density.Methods: See "Materials and Methods."QA/QC: None per se; see "Materials and Methods."Contact: David V. AldrichSource Inst.: Marine Laboratory, Texas A & M University, Galveston, TX 77550 USAAuthor: Anderson, D. M.99

Date: 1994Title: Red tidesJournal: Scientific American, August 1994Key words: red tide, bloom, phytoplankton, dinoflagellate, cyst, shellfish poisoning, biotoxin,Gymnodinium breve, pollution, ballast waterSummary: The author presents a summary of the deleterious effects of toxic red tide blooms.Topics addressed are biology, including cyst formation and germination; toxincharacteristics and poisoning; initiation, growth and hydrologic transport of bloomspecies; the correlation between blooms and increasing coastal pollution; and novelred tide infestations following transport in the ballast water of ships.Methods: None (summary)QA/QC: N/AContact: Donald M. AndersonSource Inst.: Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA02543 USAAuthor: Anderson, D. M., and Wall, D.Date: 1978Title: Potential importance of benthic cysts of Gonyaulax tamarensis and G. excavata ininitiating toxic dinoflagellate bloomsJournal: Journal of Phycology 14(2):224-234Key words: cyst, Gonyaulax [later Protogonyaulax] tamarensis, Gonyaulax excavata,dinoflagellate, bloom, hypnocysts, excystment, temperature, red tide, pellicle cystSummary: Sediments from salt ponds in Cape Cod, Massachusetts yielded hypnocysts of twotoxic dinoflagellate species that were later successfully germinated by temperatureincrease alone (to 16 o C) after incubation for six months at 5 o C, unaffected bynutrient or chelator concentrations nor light regime. The authors conclude thathypnocysts do seed recurrent annual blooms. The hypnocysts are evidently sexualzygotes whereas a form of asexual cyst commonly formed in laboratory cultures,termed a "pellicle cyst," is less durable, cannot overwinter in nature and most likelydoes not produce toxic blooms. Excystments of hypnocysts with increasingtemperature has been demonstrated in several other dinoflagellate species [andcould possibly apply to Gymnodinium breve and Alexandrium monilata].Methods: See "Materials and Methods."QA/QC: None per se; see "Materials and Methods."Contact: Donald Mark AndersonSource Inst.: Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA02543 USAAuthor: Anderson, D. M., Kulis, D. M. and Cosper, E. M.Date: 1989Title/Chap.: Immunofluorescent detection of the brown tide organism, AureococcusanophagefferensBook: Novel Phytoplankton Blooms: Causes and Impacts of Recurrent Brown Tides andOther Unusual Blooms, Coastal and Estuarine Studies 35100

Editor: E. M. Cosper, V. M. Bricelj and E. J. CarpenterPages: 213-228Publisher: Springer-VerlagKey words: immunofluorescence, brown tide, Aureococcus anophagefferens, bloom,chrysophyte, picoplankton, antibodies, antiserumSummary: The authors report the rapid, accurate detection of the brown tide organism,Aureococcus anophagefferens, with immunofluorescent detection methods, evenwhen the phytoplankton sample is mixed with A. anophagefferens in low relativeabundance. The antiserum at effective concentrations did not cross-react with anyof 46 other phytoplankton cultures from 5 algal classes, including 20 species fromthe class Chrysophycophyta; at higher antiserum concentrations, cross-reactivityoccurred with Pelagococcus subviridis, which shares some ultrastructural andpossibly phylogenetic similarities. The technique may also reliably serve indetecting the presence of A. anophagefferens in variously preserved samplesseveral years old.Methods: See “Methods”QA/QC: None per se; see “Results”Contact: Donald M. AndersonSource Inst.: Biology Department, Woods Hole Oceanographic InstitutionWoods Hole, MA 02543 USAAuthor: Anderson, D. M., Keafer, B. A., Kulis, D. M., Waters, R. M. and Nuzzi, R.Date: 1993Title: An immunofluorescent survey of the brown tide chrysophyte Aureococcusanophagefferens along the northeast coast of the United StatesJournal: Journal of Plankton Research 15(5):563-580Key words: immunofluorescence, brown tide, chrysophyte, Aureococcus anophagefferensSummary: The authors conducted surveys from Portsmouth, NH to Chesapeake Bay in 1988and 1990 to determine the population distribution of the brown tide chrysophyteAureococcus anophagefferens. A species-specific immunofluorescent techniquesensitive to as few as 10-20 cells/ml revealed that water samples from almost halfof the stations to the north and south of the geographic center of the brown tideblooms of 1985 (the Long Island area and Barnegat Bay, NJ, where highconcentrations still existed), A. anophagefferens was detected at very low cellconcentrations within a PSU salinity range of 18-32. Many of these stations, bothopen coastal and estuarine, have no history of a brown tide bloom, yet apparentlyhave the potential.Methods: See “Method.”QA/QC: None per se; see “Method.”Contact: Donald M. AndersonSource Inst.: Woods Hole Oceanographic Institution, Biology Department, Woods Hole, MA02543 USAAuthor: Baden, D. G. and Tomas, C. R.Date: 1989Title/Chap.: Variations in major toxin composition for six clones of Ptychodiscus brevis101

Book: Red tides: biology, environmental science, and toxicology. Proceedings of theFirst International Symposium on Red Tides held November 10-14, 1987, inTakamatsu, Kagawa Prefecture, JapanEditor: T. Okaichi, D. M. Anderson and T. NemotoPages: 415-418Publisher: Elsevier Science Publishing Company, Inc., New YorkKey words: toxin, clone, high pressure liquid chromatography, bloom, Texas, Florida, isolate,haploid, diploidSummary: Six Ptychodiscus brevis [now Gymnodinium breve] clones examined for toxincontent included one or more isolated from single cells collected during the 1986Texas bloom, with the remainder from Florida. The oldest clone (from Florida, ca.1953) was previously characterized as diploid, whereas the more recent isolateswere noted as haploid. In the three toxin fractions analyzed with HPLC, there waswide clonal variability; each of the recent clones was significantly different fromthe oldest. Obviously, the variability in toxin content between G. brevepopulations experiencing different environmental conditions deserves furtherattention.Methods: See "Experimental."QA/QC: None per se; see "Experimental."Contact: Daniel G. BadenSource Inst.: University of Miami Rosenstiel School of Marine and Atmospheric Science,Division of Biology and Living Resources, Miami, FL 33149 USAAuthor: Baldridge, H. D.Date: 1975Title/Chap.: Temperature patterns in the long-range prediction of red tide in Florida watersBook: Proceedings of The First International Conference on Toxic DinoflagellateBloomsEditor: V. R. LoCiceroPages: 69-79Publisher: The Massachusetts Science and Technology Foundation, Wakefield, MAKey words: surface temperature, red tide, Florida, bloom, Gymnodinium breve, dinoflagellates,toxin, bloom predictionSummary: A technique for predicting red tide blooms in the local area of the Gulf near TampaBay, Florida that depends on the strong empirical relationship between surfacewater temperature patterns and major bloom initiation is presented as a means offorecasting the likelihood of outbreaks twelve months in advance. Predictions arebased on simple indicator patterns of water temperatures from mid-January toearly April, and the author claims that such patterns have already shown strongcorrelation with five major red tides between 1957 and 1974 at Egmont Key,Florida. No claim is made of cause-effect dependency nor does the author wish todiminish the importance of other environmental conditions favoring bloominitiation.Methods: See "Methods and Results."QA/QC: None per se; see "Methods and Results."Contact: H. David Baldridge102

Source Inst.: Mote Marine Laboratory, Sarasota, Florida, USAAuthor: Barron, C. N., Jr. and Vastano, A. C.Date: 1994Title: Satellite observations of surface circulation in the northwestern Gulf of Mexicoduring March and April 1989Journal: Continental Shelf Research 14(6):607-628Key words: satellite, surface circulation, Gulf of Mexico, drifter, drogue, Texas-LouisianaShelf, current, convergence, infrared imagery, sea surface temperatureSummary: Six drift buoys drogued to 2.7 m depth in the northwestern Gulf of Mexicoprovided eight tracks over the Texas-Louisiana Shelf in March and April of 1989.Tracks indicated cross-slope and cross-shelf water movement northward towardLouisiana from the central western Gulf and a westward coastal current from theMississippi delta region to Galveston, Texas and farther south. Low-energycurrent patterns occupied the middle of the northwestern portion of the continentalshelf, and a nearshore convergence occurred between the Matagorda Peninsula andsouthern Padre Island. The effects of wind-induced currents over the shelf couldbe seen over 7 o of longitude and 3 o of latitude. Infrared satellite imageryilluminated details of the spatial scale of Gulf circulation.Methods: See "Observations and Methods."QA/QC: N/A (Physical oceanography)Contact: Charlie N. Barron, Jr.Source Inst.: Satellite Ocean Analysis Research, Department of Oceanography, Texas A & MUniversity, College Station, TX 77843 USAAuthor: Beltrami, E. J.Date: 1989Title/Ch.: Brown tide dynamics as a catastrophe modelBook: Novel Phytoplankton Blooms: Causes and Impacts of RecurrentBrown Tides and Other Unusual Blooms, Coastal and EstuarineStudies 35Editor: E. M. Cosper, V. M. Bricelj and E. J. CarpenterPages: 307-315Publisher: Springer-VerlagKey words: brown tide, Aureococcus anophagefferens, mathematical modeling,Long IslandSummary: Some interesting results of this model include infrequent outbreaksof brown tide occurring at irregular intervals with varying severityand persisting from two to five years, while low endemic densitiesof the brown tide organism persist in the intervals. Within themodel, blooms are initiated only when high salinity accompaniesambient waters sufficiently rich in nutrients to sustain a bloompopulation. While the model itself is not predictive, it may explainthe basic dynamics of brown tide outbreaks.Methods: See “The Model”QA/QC: N/A103

Contact: Edward J. BeltramiSource Inst.: Department of Applied mathematics, State University of NewYork, Stony Brook, NY 11794-3600 USAAuthor: Beltrami, E. and Cosper, E.Date: 1993Title/Ch.: Modeling the temporal dynamics of unusual bloomsBook: Toxic Phytoplankton Blooms in the Sea, Proceedings of the Fifth InternationalConference on Toxic Marine PhytoplanktonEditor: T. J. Smayda and Y. ShimizuPages: 731-735Publisher: ElsevierKey words: modeling, bloom, brown tide, Aureococcus anophagefferens, picoplankton,grazing pressureSummary: Concentrating on the form of bloom behavior characterized by continuous butvariable growth in cell numbers, a need for the right suite of conditions to initiatethe bloom and persistence even if conditions diminish, the authors identify andincorporate two major sets of factors into their mathmatical model of bloomdynamics. Using field and laboratory data from the brown tide blooms in LongIsland and Narragansett Bay to calibrate the model, the external, meterorologicalfactors combined with the internal factors of trophic system dynamics producedresults that implicate low grazing pressure as the principal selective advantage toan A. anophagefferens bloom and that mimic the fluctuating cell numbers as aproduct of chaotic population dynamics.Methods: See “Mathematical Model.”QA/QC: N/AContact: Edward BeltramiSource Inst.: State University of New York, Stony Brook, New York 11794 USAAuthor: Bidigare, R. R.Date: 1989Title/Ch.: Photosynthetic pigment composition of the brown tide alga: unique chlorophylland carotenoid derivativesBook: Novel Phytoplankton Blooms: Causes and Impacts of Recurrent Brown Tides andOther Unusual Blooms, Coastal and Estuarine Studies 35Editor: E. M. Cosper, V. M. Bricelj and E. J. CarpenterPages: 57-75Publisher: Springer-VerlagKey words: Ultraplankton, pigments, brown tide, Aureococcus anophagefferens,Chrysophyceae, carotenoids, Pelagococcus subviridis, chlorophyll c 3 ,,fucoxanthin, xanthophyll.Summary: The author discusses the possible use of pigments unique to ultraplanktonicchrysophytes as a means of identification, particularly with regard to Aureococcusanophagefferens, a brown tide microalga. Such pigments include xanthophylls,fucoxanthins, carotenoids and chlorophyll c.Methods: See “Methods.”104

QA/QC: None per se; see “Methods.”Contact: Robert R. BidigareSource Inst.: Geochemical & Environmental Research Group, Department ofOceanography, Texas A&M University, College Station, TX77843 USAAuthor: Bricelj, V. M., Epp, J. and Malouf, R. E.Date: 1987Title: Intraspecific variation in reproductive and somatic growth cycles of bay scallopsArgopecten irradiansJournal: Marine Ecology Progress Series 36:123-137Key words: reproductive cycle, somatic growth cycle, bay scallop, Argopecten irradians,fecundity, adductor muscle, New York, picoplankton, bloomSummary: This study examined variability in fecundity, reproductive growth cycles andsomatic growth cycles in four New York populations of the bay scallopArgopecten irradians. The brown tide bloom of 1985 caused starvation andreduced adult muscle weight by 76% relative to 1984. Once the bloom waned inlate summer, surviving scallops showed a 3-fold increase in mean muscle weight inSeptember.Methods: See "Methods."QA/QC: None per se; see "Methods."Contact: V. M. BriceljSource Inst.: Marine Sciences Research Center, State University of New York at Stony Brook,New York 11794 USAAuthor: Bricelj, V. M. and Kuenstner, S. H.Date: 1989Title/Ch.: Effects of the “brown tide” on the feeding physiology and growth of bay scallopsand musselsBook: Novel Phytoplankton Blooms: Causes and Impacts of Recurrent Brown Tides andOther Unusual Blooms, Coastal and Estuarine Studies 35Editor: E. M. Cosper, V. M. Bricelj and E. J. CarpenterPages: 491-509Publisher: Springer-VerlagKey words: brown tide, bay scallop, mussel, bloom, chrysophyte, Aureococcusanophagefferens, Argopecten irradians, Mytilus edulis, bivalves, Long IslandSummary: This study tests the small size, high density and poor digestibility mechanisms inthe interaction between A. anophagefferens and juveniles of both mussels and bayscallops in feeding trials. Results indicated neither small size, indigestibility norpoor nutritional quality as reasons for harmful effects in bivalves, but rather thechronic toxicity of A. anophagefferens induced by direct contact of brown tidecells in high densities with bivalve tissue.Methods: See “Methods.”QA/QC: None per se; see “Methods.”Contact: V. Monica Bricelj105

Source Inst.: Marine Sciences Research Center, State University of New York, Stony Brook,NY 11794-5000 USAAuthor: Bricelj, V. M., Fisher, N. S., Guckert, J. B. and Fu-Lin, E. C.Date: 1989Title/Ch.: Lipid composition and nutritional value of the brown tide alga AureococcusanophagefferensBook: Novel Phytoplankton Blooms: Causes and Impacts of Recurrent Brown Tides andOther Unusual Blooms, Coastal and Estuarine Studies 35Editor: E. M. Cosper, V. M. Bricelj and E. J. CarpenterPages: 85-100Publisher: Springer-VerlagKey words:Summary:lipids, brown tide, Aureococcus anophagefferens, bloom, chrysophyte, fatty acidsOf the two hypotheses potentially explaining the brown tide’s negative impact onbivalves, chronic toxicity or nutritional inadequacy, this study concerns the latter,analyzing the variable lipid content, lipid fractionation and fatty acid compositionof Aureococcus anophagefferens in culture during exponential growth andstationary phase with respect to possible deficiencies in polyunsaturated fatty acidsessential for bivalve growth. Results indicated no comparative deficiency betweenessential fatty acids in A. anophagefferens and other algae known to be nutritiousfor bivalves, which suggests that the chronic toxicity hypothesis is more likely.Methods: See “Methods.”QA/QC: None per se; see “Methods.”Contact: V. Monica BriceljSource Inst.: Marine Sciences Research Center, State University of New York, Stony Brook,NY 11794-5000 USAAuthor: Buskey, E. J.Date: 1994Title: Impact of a persistent “brown tide” algal bloom on the Laguna Madre of SouthTexas. Final report to the Texas Higher Education Coordinating Board, AdvancedTechnology Program.Pages: 5 pp.Key words: brown tide, Pelageophycae, Laguna Madre, chrysophyte, Halodule wrightii,Acartia tonsa, Streblospio benedicti, bay anchovy, black drum, spotted sea troutSummary: This report summarizes the adverse impact of the Texas brown tide’s almost fiveyearpersistence on the flora and fauna of the Laguna Madre, including shoalgrass,copepods, microzooplankton, polychaetes and fish larvae.Methods: N/AQA/QC: N/AContact: Edward J. BuskeySource Inst.: Marine Science Institute, The University of Texas at Austin, P. O. Box 1267,Port Aransas, TX 78373 USAAuthor: Buskey, E. J., and Stockwell, D. A..Date: 1993106

Title/Ch.: Effects of a persistent “brown tide” on zooplankton populations in the LagunaMadre of South TexasBook: Toxic Phytoplankton Blooms in the SeaEditor: T. J. Smayda and Y. ShimizuPages: 659-666Publisher: Elsevier Science Publishers B. VKey words: brown tide, zooplankton, Laguna Madre, Texas, nanoplankton, chrysophyte,mesozooplankton, microzooplankton, Baffin Bay, Acartia tonsaSummary: Relates effects on zooplankton of a brown tide due to an unidentified Type IIInanoplanktonic chrysophyte of 4-5 µm diameter that appeared in regions of theSouth Texas coast centering around the Laguna Madre including Baffin Bay from6/90-7/91 and continuing. Cell densities ranged from 0.5-6.0 x 10 6 cells/ml,dausing sharp decline in micro- and mesozooplankton populations.Methods: See “Methods.”QA/QC: None per se; see “Methods.”Contact: Edward J. BuskeySource Inst.: Marine Science Institute, The University of Texas at Austin, Port Aransas, TX78373 USAAuthor: Caron, D. A., Lim, E. L., Kunze, H., Cosper, E. M. and Anderson, D. M.Date: 1989Title/Ch.: Trophic interactions between nano- and microzooplankton and the “brown tide”Book: Novel Phytoplankton Blooms: Causes and Impacts of Recurrent Brown Tides andOther Unusual Blooms , Coastal and Estuarine Studies 35Editor: E. M. Cosper, V. M. Bricelj and E. J. CarpenterPages: 265-294Publisher: Springer-VerlagKey words: nanoplankton, microzooplankton, brown tide, bloom, grazing, Aureococcusanophagefferens, chrysophyte, protozoa, Long IslandSummary: Examines the ability of five protozoan species to consume A. anophagefferens inlaboratory culture, since the size of the brown tide organism is ideal for protozoangrazers. Paradoxically, brown tide outbreaks have suffered no apparent reductionby protozoan grazers that typically reproduce at greater rates than those reportedfor A. anophagefferens. Results revealed that two of the five protozoan grazerswere able to consume and outgrow the A. anophagefferens cultures. The authorsspeculate that brown tide organisms could achieve bloom proportions if lowdensities of protozoan consumers were present at the time of bloom initiation andthat this scenario is more likely than chemical inhibition based on the results ofthese experiments.Methods: See “Methods.”QA/QC: None per se; see “Methods.”Contact: David A. CaronSource Inst.: Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA02543 USAAuthor: Castro, L. R. and Cowen, R. K.Date: 1989107

Title/Ch.: Growth rates of bay anchovy (Anchoa mitchilli) in Great South Bay underrecurrent brown tide conditions, summers 1987 and 1988Book: Novel Phytoplankton Blooms: Causes and Impacts of Recurrent Brown Tides andOther Unusual Blooms , Coastal and Estuarine Studies 35Editor: E. M. Cosper, V. M. Bricelj and E. J. CarpenterPages: 663-674Publisher: Springer-VerlagKey words: bay anchovy, Anchoa mitchilli, Great South Bay, brown tide, larvae,phytoplankton, bloom, growth rate, otolithSummary: Examining the possible effects of dense brown tide on larval growth rates of bayanchovy (< 13 mm SL) in Great South Bay, Long Island, the authors discoveredthat neither increased turbidity nor elevated average bay surface temperatureproduced a significant change in average larval growth rates as determined byotolith diameter, though the rates were not corrected for shrinkage and werepossibly higher than those reported.Methods: See “Methods.”QA/QC: None per se; see “Methods.”Contact: Leonardo R. CastroSource Inst.: Marine Sciences Research Center, State University of New York at Stony Brook,Stony Brook, NY 11794-5000 USAAuthor: Cochrane, J. D., and Kelly, F. J.Date: 1986Title: Low-frequency circulation on the Texas-Louisiana continental shelfJournal: Journal of Geophysical Research 91(C9):10,645-10,659Key words: low-frequency circulation, continental shelf, Texas, Louisiana, coastal current,wind stress, convergence, salinity, geopotential, cyclonic gyreSummary: The authors, using several data series on coastal winds, current measurements, anddistributions of surface salinity and geopotential, offer a sketch of the lowfrequencysurface circulation above the Texas-Louisiana Shelf. They infer theexistence of a cyclonic gyre composed of a nearshore southward coastal jet, anoffshore northerly to easterly flow over the shelf break and lateral componentscompleting the circuit. The gyre's southern end marks a convergence of coastalcurrents between Port Isabel and Port Aransas. The integrity of the gyre wasmaintained in all months but July.Methods: None (Data interpretation)QA/QC: N/AContact: J. D. CochraneSource Inst.: Department of Oceanography, Texas A & M University, College Station, TX,USAAuthor: Collier, A.Date: 1958Title: Some biochemical aspects of red tides and related oceanographic problemsJournal: Limnol. Oceanogr. 3:33-39108

Key words: red tide, bloom, plankton, Prorocentrum, Gymnodinium breve, Florida, Gulf ofMexico, copper, hydrogen sulfide, dinoflagellateSummary: The author suggests that a complex of biological factors causes a red tide bloom,and physical factors cause its mechnical concentration. Biologically active organiccompounds are important, and the paper discusses their possible modes of action.The armored dinoflagellate Prorocentrum served as a means of estimatingdinoflagellate potential in terms of producing free organic substances in the aquaticenvironment. Regarding G. breve, the interactions of a particular bacterial colonytype and its production of vitamin B12 with the red tide organism implies that thedinoflagellate may be producing an organic substrate that indirectly conditions thewater for its own growth. West Florida waters from different sources andcollection times have varied effects on G. breve growth; this paper describessulfides as suitable substitutes for organic chelators (and abundantly supplied fromWest Florida estuaries) and copper as highly toxic to the dinoflagellate (in widelyvarying concentrations off West Florida).Methods: None per se; see text.QA/QC: None per se.Contact: Albert CollierSource Inst.: U. S. Fish and Wildlife Service, Galveston, TX, USAAuthor: Collier, A., Wilson, W. B. and Borkowski, M.Date: 1969Title: Responses of Gymnodinium breve Davis to natural waters of diverse originsJournal: J. Phycol. 5:168-172Key words: Gymnodinium breve, growth, enrichment, chelator, nutrient, Florida,dinoflagellate, sulfide, plankton, bloomSummary: Using river water and seawater collected from different locations in differentseasons on and off the coast of West Florida, the authors examined subsequentgrowth of the dinoflagellate Gymnodinium breve when cultured in those waterswith and without enrichment with chelated metals (e. g., EDTA-Fe), sulfide,nitrogen, phosphorus and vitamins. All additions produced enhanced growthrelative to controls in river water. For both water types, a large growth responsewas noted with waters collected during the summer of 1966, perhaps linked toriverine contributions to the seawater samples. Of all additives, sulfides, naturalchelators, nitrogen and phosphorus may best contribute to blooms. Given theunpredictability of red tide blooms, the necessity of continual water sampling isimplied in order to characterize water quality during a bloom.Methods: See "Materials and Methods."QA/QC: None per se; see "Materials and Methods."Contact: Albert CollierSource Inst.: Department of Biological Science, Florida State University, Tallahassee, FL32306 USAAuthor: Connell, C. H. and Cross, J. B.Date: 1950109

Title: Mass mortality of fish associated with the protozoan Gonyaulax in the Gulf ofMexicoJournal: Science 112(2909):359-363Key words: fish, mortality, Gonyaulax sp., Gulf of Mexico, Galveston, Texas, GonyaulaxcatenellaSummary: This paper discusses the correlation of mass mortality of fish with historic reportsand a 1949 episode of red tide or luminescent water in a saltwater lagoon nearGalveston, Texas. In terms of (1) insufficient cells to define the sutures of thecellulose plates, (2) longer chains of cells and (3) different vectors for the toxin,the 1949 red tide dinoflagellate near Galveston was similar but not identical toGonyaulax catenella, the organism responsible for tainted shellfish and resultinghuman and mammal mortality (but not fish) on the Pacific coast of North America.Small quantities of sewage pollution, wide and variable readings of dissolvedoxygen content and unusually high values for biochemical oxygen demand in theaffected lagoon were concurrent with the occurrence of this Gonyaulax sp.Methods: See “Methods.”QA/QC: None per se; see “Methods.”Contact: Cecil H. ConnnellSource Inst.: Dept. of Preventive Medicine, Medical Branch, Univ. of Texas, GalvestonAuthor: Cosper, E. M.Date: 1987Title: Culturing the "brown tide" algaJournal: Applied Phycology ForumKey words: culture, brown tide, algae, bloom, Long Island, phytoplankton, Chrysophyceae,Aureococcus anophagefferens, growth rate, growth factorsSummary: Attempts to culture the chrysophyte responsible for the algal blooms thatdevastated eelgrass and bay scallop populations in Long Island bays in 1985 weresuccessful. Isolates exhibited fast growth rates (up to 3/day at 20 degrees C),though growth was poor in f/2-enriched standard media. Natural filtered seawater,however, when combined with f/2 media, produced maximal growth rates,suggesting certain growth factors in the bloom water. The organic additive,sodium glycerophosphate, enhanced growth significantly, whereas other glucoseand succinate did not.Methods: None per se; see text (Research note)QA/QC: N/AContact: Elizabeth M. CosperSource Inst.: Marine Sciences Research Center, State University of New York, Stony Brook,New York 11794 USAAuthor: Cosper, E. M., Dennison, W. C., Carpenter, E. J., Bricelj, V. M., Mitchell, J. G.,Duenstner, S. H., Colflesh, D. and Dewey, M.Date: 1987Title: Recurrent and persistent brown tide blooms perturb coastal marine ecosystemJournal: Estuaries 10(4):284-290110

Key words: brown tide, bloom, chrysophyte, Long Island, eelgrass, bay scallop, Rhode Island,New jersey, microalgaeSummary: Culture experiments with the previously undescribed brown tide microalgaimplicated a role for stimulatory growth factors in bloom seawater, aided bymeterological factors that prompted blooms in Long Island, Rhode Island and NewJersey waters in the summers of 1985 and 1986. Bloom concentrations exceeded10 9 cells/liter in Long Island bays, harming eelgrass beds and bay scalloppopulations.Methods: See “Methods and Materials.”QA/QC: None per se; see “Methods and Materials.”Contact: Elizabeth M. CosperSource Inst.: Marine Sciences Research Center, State University of New York, StonyBrook, New York 11794 USAAuthor: Cosper, E. M., Carpenter, E. J. and Cottrell, M.Date: 1989Title/Ch.: Primary productivity and growth dynamics of the “brown tide” in Long IslandembaymentsBook: Novel Phytoplankton Blooms: Causes and Impacts of Recurrent Brown Tides andOther Unusual Blooms, Coastal and Estuarine Studies 35Editor: E. M. Cosper, V. M. Bricelj and E. J. CarpenterPages: 139-158Publisher: Springer-VerlagKey words: brown tide, Long Island, bloom, Aureococcus anophagefferens, Nannochloris sp.,picoplankton, Pelagococcus subviridisSummary: Throughout the brown tide blooms of 1985-88, phytoplankton biomass andproductivity did not differ from pre-bloom years, but Aureococcusanophagefferens dominated the species composition, apparently controlled bymicroflagellate grazers, yet still often as dense as 10 8 cells/l. No notable changes ininorganic nutrient levels could explain the blooms, though certain organic nutrientssuch as glycerophosphates and chelators were implicated. Historical blooms in thesummers of “small forms” and of usually diverse composition have not beenuncommon in Long Island waters. A. anophagefferens has been detected in nonbloomdensities in northeast coastal waters in general, implying that the LongIsland blooms occurred due to unique and persistently favorable conditions for A.anophagefferens, conditions which may have stimulated excystation of a possibleresting stage.Methods: See “Methods.”QA/QC: None per se; see “Methods.”Contact: Elizabeth M. CosperSource Inst.: Marine Sciences Research Center, State University of New York, Stony Brook,NY 11794 USAAuthor: Cosper, E. M., Lee, C. and Carpenter, E. J.Date: 1990Title/Ch.: Novel “brown tide” blooms in Long Island embayments: a search for the causes111

Book: Toxic Marine Phytoplankton, Proceedings of the Fourth International Conferenceon Toxic Marine PhytoplanktonEditor: E. Granéli, B. Sundström, L. Edler and D. M. AndersonPages: 17-28Publisher: ElsevierKey words: brown tide, bloom, Long Island, chrysophyte, Aureococcus anophagefferens,Pelagococcus subviridis, trace elements, chelators, organic nutrientsSummary: Once a suite of favorable environmental factors initiates a bloom, Aureococcusanophagefferens appears to have a competitive advantage over other possiblycoincident phytoplankton species due to its heterotrophic and photoadaptivecapabilities. Factors contributing to blooms may include high salinities resultingfrom drought, rainfall-induced input of organic and/or micronutrients, reducedgrazing pressure and restricted flushing of bay waters. A. anophagefferens bearssome resemblance to the open ocean chrysophyte, Pelagococcus subviridis.Methods: N/A (review article)QA/QC: N/AContact: Elizabeth M. CosperSource Inst.: Marine Sciences Research Center, State University of New York, Stony Brook,New York 11794 USAAuthor: Cosper, E. M., Dennison, W., Milligan, A., Carpenter, E. J., Lee, C., Holzapfel, J.and Milanese, L.Date: 1989Title/Ch.: An examination of the environmental factors important to initiating and sustaining“brown tide” bloomsBook: Novel Phytoplankton Blooms: Causes and Impacts of Recurrent Brown Tides andOther Unusual Blooms, Coastal and Estuarine Studies 35Editor: E. M. Cosper, V. M. Bricelj and E. J. CarpenterPages: 317-340Publisher: Springer-VerlagKey words: brown tide, bloom, Long Island, flushing rate, Aureococcus anophagefferens,picoplanktonSummary: The authors hypothesize that the brown tide organism, Aureococcusanophagefferens, will likely bloom when long-term anthropogenic and/or othersources of eutrophication combine with atypical meteorological andhydrographical conditions (e.g., high salinity). The competitive superiority of A.anophagefferens relative to other phytoplankton does not appear to be the resultof an allelopathic (toxic) exudate, but is more likely due to miconutrient needs,efficient use of low light levels, and heterotrophic capabilities, including an unusualability to take up glutamic acid and glucose rapidly as energy and carbon sources,with a possible reduction in grazing pressure.Methods: See “Methods.”QA/QC: None per se; see “Methods.”Contact: Elizabeth M. CosperSource Inst.: Marine Sciences Research Center, State University of New York, Stony Brook,NY 11794 USA112

Author: Cosper, E. M., Garry, R. T., Milligan, A. J. and Doall, M. H.Date: 1993Title/Ch.: Iron, selenium and citric acid are critical to the growth of the “brown tide”microalga, Aureococcus anophagefferensBook: Toxic Phytoplankton Blooms in the Sea, Proceedings of the Fifth InternationalConference on Toxic Marine PhytoplanktonEditor: T. J. Smayda and Y. ShimizuPages: 667-673Publisher: ElsevierKey words: iron, selenium, citric acid, brown tide, microalgae, Aureococcus anophagefferens,chelators, trace elements, chrysophyte, bloomSummary: This study evaluated the impact of chelators and essential trace elements on thegrowth of A. anophagefferens, of which both iron and selenium were found to becritical. Citric acid was the most effective chelator for growth enhancement, and,since it has replaced phosphates in some commercial detergents in New York, theauthors suggest that its role in eutrophication should be examined. Using bloomand non-bloom water samples filtered through 5 µm mesh and manipulated withregard to light and Se and/or Fe additions, results indicated that Fe alone increasedby several times the growth rates of A. anophagefferens in bloom water under highlight; only Fe with Se increased A. anophagefferens growth rates in non-bloomwater, but only at low light levels.Methods: See “Methods.”QA/QC: None per se; see “Methods” and “Results.”Contact: Elizabeth M. CosperSource Inst.: Marine Sciences Research Center, State University of New York, Stony Brook,NY 11794 USAAuthor: Davis, C. C.Date: 1948Title: Gymnodinium brevis sp. nov., a cause of discolored water and animal mortality inthe Gulf of MexicoJournal: Botanical Gazette 109(3):358-360Key words: Gymnodinium brevis, discolored water, fish mortality, Gulf of Mexico, Florida,plankton, cell, chromatophoresSummary: The description and classification of the then-novel red tide dinoflagellate nowknown as Gymnodinium breve occupies the majority of text but is preceded bysome examples of mass mortality caused by this organism off the west coast ofFlorida in 1947.Methods: None (taxonomic description/classification)QA/QC: N/AContact: Charles C. DavisSource Inst.: University of Miami Marine Laboratory, Coral Gables, Florida, USAAuthor: Dennison, W. C., Marshall, G. J. and Wigand, C.Date: 1989Title/Ch.: Effect of “brown tide” shading on eelgrass (Zostera marina L.) distributions113

Book: Novel Phytoplankton Blooms: Causes and Impacts of Recurrent Brown Tides andOther Unusual Blooms, Coastal and Estuarine Studies 35Editor: E. M. Cosper, V. M. Bricelj and E. J. CarpenterPages: 675-692Publisher: Springer-VerlagKey words: brown tide, eelgrass, Zostera marina, Aureococcus anophagefferens, Long Island,distribution, die-backSummary: A lack of historical data on eelgrass distributions in Long Island bays prevented theauthors from making definitive statements about any deleterious effects by browntide on eelgrass populations since the summer blooms of 1985-88, yet the browntide did reduce light available to the eelgrass beds in bloom areas. Most bays hadless eelgrass during the 1988 survey than indicated in historic, pre-bloom aerialphotographs.Methods: See “Methods.”QA/QC: None per se; see “Methods.”Contact: William C. DennisonSource Inst.: Horn Point Environmental Laboratories, Center for Environmental and EstuarineStudies, University of Maryland, P. O. Box 775, Cambridge, MD 21613 USAAuthor: Deyoe, H. R. and Suttle, C. A.Date: 1994Title: The inability of the Texas “brown tide” alga to use nitrate and the role of nitrogenin the initiation of a persistent bloom of this organism.Journal: J. Phycol. 30:800-806Key words: Texas, brown tide, bloom, nitrate, nitrate reductase, nitrogen, plankton,Aureococcus anophagefferens, Laguna Madre, nitrite, ammoniumSummary: The Texas brown tide organism differs slightly but significantly from the NewEngland brown tide alga, Aureococcus anophagefferens, in that the Texas browntide alga apparently lacks the enzyme nitrate reductase, making it unable to useNO - 3 for growth. It can, however, use nitrite and ammonium, the latter of whichwas in unusually high concentrations after two severe freezes in December 1989and January 1990 caused declines in invertebrate biomass and mortality in fishpopulations and apparently stimulated the Texas brown tide bloom.Methods: See “Materials and Methods.”QA/QC: None per se; see “Materials and Methods.”Contact: Hudson R. DeyoeSource Inst.: CCBNEP, Texas A & M University-Corpus Christi, 6300 Ocean Drive, CorpusChristi, TX 78412 USAAuthor: Draper, C., Gainey, L., Shumway, S. and Shapiro, L.Date: 1990Title/Ch.: Effects of Aureococcus anophagefferens (“brown tide”) on the lateral cilia of 5species of bivalve molluscsBook: Toxic Marine Phytoplankton, Proceedings of the Fourth International Conferenceon Toxic Marine PhytoplanktonEditor: E. Granéli, B. Sundström, L. Edler and D. M. Anderson114

Pages: 128-131Publisher: ElsevierKey words: Aureococcus anophagefferens, brown tide, cilia, bivalve, mollusc, Mya arenaria,Geukensia demissa, Argopecten irradians, Mercenaria mercenaria, Mytilusedulis, dopamineSummary: Aureococcus anophagefferens caused significant decreases in lateral ciliary activityin isolated gills of Mercenaria mercenaria and Mytilus edulis as did theneurotransmitter dopamine. Neither A. anophagefferens nor dopamine, however,had any effect on lateral ciliary activity of Mya arenaria, Geukensia demissa orArgopecten irradians.Methods: See “Materials and Methods.”QA/QC: None per se; see “Materials and Methods.”Contact: Christy DraperSource Inst.: Department of Biological Sciences, University of Southern Maine, Portland, ME04103 USAAuthor: Duguay, L. E., Monteleone, D. M. and Quaglietta, C.-E.Date: 1989Title/Ch.: Abundance and distribution of zooplankton and ichthyoplankton in Great SouthBay, New York during the brown tide outbreaks of 1985 and 1986Book: Novel Phytoplankton Blooms: Causes and Impacts of Recurrent Brown Tides andOther Unusual Blooms, Coastal and Estuarine Studies 35Editor: E. M. Cosper, V. M. Bricelj and E. J. CarpenterPages: 599-623Publisher: Springer-VerlagKey words: zooplankton, ichthyoplankton, Great South Bay, New York, brown tide,chrysophyte, Aureococcus anophagefferens, bivalve larvae, trophodynamics,Acartia sp.Summary: Investigations of plankton trophodynamics in Great South Bay, NY wereunderway when brown tide blooms of Aureococcus anophagefferens occurred inthe summers of 1985 and 1986, the former apparently more severe. Summerbivalve larvae were significantly higher in both peak and average density in 1986 asopposed to 1985, confirming previous reports of mortality and/or reduction intissue dry weights in bivalves exposed to brown tide blooms. The authorsspeculate that excess rainfall in May and June of 1985 initiated the brown tide,with the bloom occurring at a time when phytoplankton grazers were notabundant.Methods: See “Methods.”QA/QC: None per se; see “Methods.”Contact: Linda E. DuguaySource Inst.: University of Maryland, Center for Environmental and Estuarine Studies,Chesapeake Biological Laboratory, P. O. Box 38, Solomons, MD 20688-0038USAAuthor: Durbin, A. G. and Durbin, E. G.Date: 1989115

Title/Ch.: Effect of the “brown tide” on feeding, size and egg laying rate of adult femaleAcartica tonsaBook: Novel Phytoplankton Blooms: Causes and Impacts of Recurrent Brown Tides andOther Unusual Blooms, Coastal and Estuarine Studies 35Editor: E. M. Cosper, V. M. Bricelj and E. J. CarpenterPages: 625-646Publisher: Springer-VerlagKey words: brown tide, Acartia tonsa, picoplankton, Narragansett Bay, chrysophyte,Aureococcus anophagefferens, bloom, copepods, Greenwich Bay,protozooplanktonSummary: Relates the impact of a picoalgal bloom in Narragansett Bay beginning in the earlysummer of 1985. The then undescribed 2 µm chrysophyte, now known asAureococcus anophagefferens, negatively affected egg laying rate, gut pigments,body size and condition factor of adult female Acartia tonsa copepods whencomparisons were made between field observations and laboratory manipulations.The authors suggest that (1) a regional climatological or hydrographic changeaffected or worked in concert with temperature, light and nutrients to favor thebloom, and/or (2) predation pressure affected the size composition of thephytoplankton community, favoring the picoplankton that are thought to becontrolled by protozooplankton predators.Methods: See “Methods.”QA/QC: None per se; see “Methods.”Contact: Ann G. DurbinSource Inst.: University of Rhode Island, Graduate School of Oceanography, Narragansett,Rhode Island 02882 USAAuthor: Dunton, K. H.Date: 1994Title: Seasonal growth and biomass of the subtropical seagrass Halodule wrightii inrelation to continuous measurements of underwater irradianceJournal: Marine BiologyKey words: growth, biomass, seagrass, Halodule wrightii, underwater irradiance, PAR, Texas,chrysophyte, brown tide, bloomSummary: Three different Texas estuaries, including brown tide-stricken Laguna Madre, weresites for studies of continuous underwater irradiance measurements and concurrentleaf elongation and plant biomass for the seagrass Halodule wrightii over one tofour years. The brown tide bloom significantly decreased spring leaf elongationrates and reduced below-ground biomass by almost 50%.Methods: See "Materials and Methods."QA/QC: None per se; see "Materials and Methods."Contact: Ken H. DuntonSource Inst.: The University of Texas at Austin, Marine Science Institute, P. O. Box 1267, PortAransas, TX 78373 USAAuthor: Dzurica, S.Date: 1988116

Thesis: Role of environmental variables, specifically organic compounds andmicronutrients, in the growth of Aureococcus anophagefferensPages: 122 pp.Source: Marine Environmental Sciences Program, State University of New York at StonyBrookKey words: micronutrient, Aureococcus anophagefferens, brown tide, microalga, Long Island,chrysophyte, organic phosphorus, chelator, trace metal, uptake rateSummary: Noting that standard culture media (f/2 Enriched Instant Ocean) supported slowgrowth rates in Long Island brown tide cultures, the author conducted a series ofexperiments in an attempt to determine factors contributing to bloom conditions.Organic rather than inorganic phosphorus compounds greatly enhanced growth asdid adding the chelators nitrilotriacetic acid and citric acid. Comparisons of uptakerates for C-14 labeled organic compounds between Aureococcus anophagefferensand five other species of microalgae which co-occur with the brown tide. A.anophagefferens exhibited a faster uptake rate for glutamic acid whenaccompanied by inorganic nitrogen, but not when glutamic acid was the sole Nsource. A. anophagefferens showed the highest uptake rate of glucose per unit cellvolume but not with the highest uptake rate constant per cell. For everycompound tested, however, A. anophagefferens demonstrated an advantage inuptake rate per unit cell volume.Methods: See "Methods and Materials," pp. 6-16.QA/QC: See "Methods and Materials."Contact: Cindy LeeSource Inst.: Marine Sciences Research Center, State University of New York, Stony Brook,NY 11794 USAAuthor: Dzurica, S., Lee, C. and Cosper E. M.Date: 1989Title/Ch.: Role of environmental variables, specifically organic compounds andmicronutrients, in the growth of the chrysophyte Aureococcus anophagefferensBook: Novel Phytoplankton Blooms: Causes and Impacts of Recurrent Brown Tides andOther Unusual Blooms, Coastal and Estuarine Studies 35Editor: E. M. Cosper, V. M. Bricelj and E. J. CarpenterPages: 229-252Publisher: Springer-VerlagKey words: micronutrients, chrysophyte, Aureococcus anophagefferens, phytoplankton,bloom, brown tide, organic phosphorus, trace metals, chelatorsSummary: With a two-fold purpose, this study sought to tailor culture media to supportoptimal growth of Aureococcus anophagefferens in order to identify possiblecommon environmental factors between culture media and bloom water and toexperimentally evaluate growth of A. anophagefferens relative to otherphytoplankton in an attempt to explain long-term dominance. Replacing inorganicphosphate in f/2 EIO medium with the organic phosphorus compoundsglycerophosphate and fructose-1,6-diphosphate stimulated growth in A.anophagefferens, as did the chelators citric acid and nitrilotriacetic acid. Traceelements accompanied by the chelator EDTA also enhanced growth. In situ117

chelation, therefore, may be an important growth factor. A. anophagefferens has amore rapid uptake rate for glutamic acid and glucose than three co-occurringphytoplankton species (diatoms and a green alga), perhaps conferring acompetitive advantage.Methods: See “Methods.”QA/QC: None per se; see “Methods.”Contact: Susan DzuricaSource Inst.: Marine Sciences Research Center, State University of New York, StonyBrook, NY 11794 USAAuthor: Elliott, B. A.Date: 1982Title: Anticyclonic rings in the Gulf of MexicoJournal: Journal of Physical Oceanography 12:1292-1309Key words: anticyclonic ring, Gulf of Mexico, Loop Current, heat budget, salt budget,Caribbean subtropical underwater, western anticyclonic cell, circulationSummary: Historical data sets provided evidence that three anticyclonic rings separated fromthe Loop Current in the eastern Gulf of Mexico during the twelve monthsfollowing October of 1966. Translating westward at a mean speed of 2.1 km/day,the rings' mean radius was 183 km, and their estimated life span was one year. Theheat and salt provided by these rings to the western Gulf must play important rolesin the heat and salt budgets of the Gulf. Convective mixing in winter graduallyreduced the higher ring salinity to values typical of Gulf of Mexico common water.Methods: None (Data interpretation)QA/QC: N/AContact: W. D. Nowlin, Jr.Source Inst.: Department of Oceanography, Texas A & M University, College Station, TX77843 USAAuthor: Eng-Wilmot, D. L., McCoy, L. F., Jr. and Martin, D. F.Date: 1979Title/Ch.: Isolation and synergism of a red tide (Gymnodinium breve) cytolytic factor(s) fromcultures of Gomphosphaeria aponinaBook: Toxic Dinoflagellate Blooms, Proceedings of the Second International Conferenceon Toxic Dinoflagellate Blooms, Key Biscayne, Florida, Oct. 31-Nov. 5, 1978Editor: D. L. Taylor and H. H. SeligerPages: 355-360Publisher: Elsevier/North-Holland, Inc.Key words: red tide, Gymnodinium breve, cytolytic factor, Gomphosphaeria aponina,dinoflagellate, blue-green alga, aponinSummary: The blue-green alga Gomphosphaeria aponina yields a cytolytic factor (“aponin”)active towards the unarmored red tide dinoflagellate Gymnodinium breve.Chloroform extractions at neutral pH produced maximum yields of aponin, purifiedby any one of three chromatographic techniques. Separate fractions showedobvious losses of total and specific activity, and a synergistic relationship amongthe separate components is supported by evidence.118

Methods: See “Materials and Methods.”QA/QC: See “Materials and Methods.”Contact: D. F. MartinSource Inst.: Department of Chemistry, University of South Florida, Tampa, FL 33620 USAAuthor: Eng-Wilmot, D. L., Henningsen, B. F., Martin, D. F. and Moon, R. E.Date: 1979Title/Ch.: Model solvent systems for delivery of compounds cytolytic towards GymnodiniumbreveBook: Toxic Dinoflagellate Blooms, Proceedings of the Second International Conferenceon Toxic Dinoflagellate Blooms, Key Biscayne, Florida, Oct. 31-Nov. 5, 1978Editor: D. L. Taylor and H. H. SeligerPages: 361-366Publisher: Elsevier/North-Holland, Inc.Key words: solvent, cytolytic compounds, Gymnodinium breve, aponin, dinoflagellate, sterol,Gomphosphaeria aponina, liposomes, micelles, red tideSummary: A sterol (C 29 H 49 OR) isolated and purified from cultures of the cyanobacteriumGomphosphaera aponina is cytolytic towards the toxigenic red tide dinoflagellateGymnodinium breve. Because the sterol is hydrophobic, it must be delivered toseawater in a non-toxic solvent system. Two are presented as promising fortreatment of localized red tide blooms, liposomes and micelles, the latter beingsuperior.Methods: See “Materials and Methods.”QA/QC: See “Materials and Methods.”Contact: D. L. Eng-WilmotSource Inst.: Department of Chemistry, University of Oklahoma, Norman, Oklahoma 73019USAAuthor: Freeberg, L. R., Marshall, A. and Heyl, M.Date: 1979Title/Ch.: Interrelationships of Gymnodinium breve (Florida red tide) within thephytoplankton communityBook: Toxic Dinoflagellate Blooms, Proceedings of the Second International Conferenceon Toxic Dinoflagellate Blooms, Key Biscayne, Florida, Oct. 31-Nov. 5, 1978Editor: D. L. Taylor and H. H. SeligerPages: 139-144Publisher: Elsevier/North-Holland, Inc.Key words: Gymnodinium breve, red tide, Florida, phytoplankton, diatom, flagellate,dinoflagellate, lysis, growth, inhibitionSummary: Medium in which G. breve had been grown was subsequently used as a mediumfor each of 28 phytoplankton species in axenic cultures. The medium significantlyinhibited growth in 18 species, though its effect, while species-specific, variedwithin species. The population levels of several diatoms and dinoflagellates andone flagellate barely increased above inoculum concentrations; two dinoflagellateinocula suffered lysis. Toxin extracts totally arrested growth in eight of twelve119

species (4 diatoms and 4 dinoflagellates). Column chromotography could notseparate the algal inhibition component from the ichthyotoxin.Methods: See “Materials and Methods.”QA/QC: None per se; see “Materials and Methods.”Contact: Larry R. FreebergSource Inst.: Mote Marine Laboratory, 1600 City Island Park, Sarasota, FloridaAuthor: Gaffney, R. J.Date: 1992Title: Brown tide comprehensive assessment and management program summaryPages: 40 pp.Publisher: Suffolk County Department of Health Services, NYKey words: brown tide, algal bloom, Aureococcus anophagefferens, Peconic Bay, FlandersBay, Shinnecock Bay, Moriches Bay, Great South BaySummary: This report concludes that the Aureococcus anophagefferens brown tideapparently was not triggered by the conventional macronutrients nitrogen andphosphorus, but may have been caused by other factors such as meteorologicalpatterns and specific chemicals (chelators, organic nutrients, metals). The reportrecommends, among other things, further research on viral control of the browntide and the relationship between dimethyl sulfide and zooplankton grazers.Methods: N/A (Summary report)QA/QC: N/AContact: Robert J. Gaffney, Suffolk County ExecutiveSource Inst.: Suffolk County Department of Health Services, NYAuthor: Gainey, L. F., Jr. and Shumway, S. E.Date: 1991Title: The physiological effect of Aureococcus anophagefferens (“brown tide”) on thelateral cilia of bivalve mollusksJournal: Biol. Bull. 181:298-306Key words: Aureococcus anophagefferens, brown tide, gill cilia, bivalve, mollusk, dopamine,ergometrineSummary: The isolated gills of eight bivalve mollusks were exposed to Aureococcusanophagefferens, the brown tide alga, resulting in a significant decrease in theactivity of the lateral cilia of the gills of five of the bivalves, whereas those of threeother species were unaffected. Only the presence of the brown tide cells producedsuch results, and the inhibition was similar to that induced by dopamine.Treatment with the dopamine antagonist ergometrine prevented loss of ciliaryactivity due to both dopamine and a water-soluble compound derived from browntide cells exposed to amylase. This dopamine-like, brown tide inhibitorycompound was likely released upon partial digestion by the isolated gills.Methods: See “Materials and Methods.”QA/QC: None per se; see “Materials and Methods.”Contact: Louis F. GaineySource Inst.: Department of Biological Sciences, University of Southern Maine, Portland, Maine04103 USA120

Author: Gallager, S. M., Stoecker, D. K. and Bricelj, V. M.Date: 1989Title/Ch.: Effects of the brown tide alga on growth, feeding physiology and locomotorybehavior of scallop larvae (Argopecten irradians)Book: Novel Phytoplankton Blooms: Causes and Impacts of Recurrent Brown Tides andOther Unusual Blooms, Coastal and Estuarine Studies 35Editor: E. M. Cosper, V. M. Bricelj and E. J. CarpenterPages: 511-541Publisher: Springer-VerlagKey words: brown tide, scallop larvae, Argopecten irradians, Aureococcus anophagefferens,growth, mortalitySummary: Using scallop larvae from a local population (Woods Hole), the authorsdemonstrated in laboratory experiments that near-bloom concentrations ofAureococcus anophagefferens reduced larval growth and survival due toinefficient capture and reduced ingestion rates, the former attributed to cell surfacecharacteristics. The presence of A. anophagefferens also hindered ingestion, butnot capture, of other, nutritious algal species. Ingestion of A. anophagefferensresulted in poor nutrition or toxicity in larval scallops, though assimilationefficiency was good and equal to that for Isochrysis sp. Scallop veligers exhibitedno swimming behavior indicating recognition of the presence of A.anophagefferens as they do with common algal prey such as Isochrysis sp.Methods: See “Methods.”QA/QC: None per se; see “Methods.”Contact: Scott M. GallagerSource Inst.: Woods Hole Oceanographic Institution, Woods Hole, MA 02543 USAAuthor: Gallegos, S.Date: 1990Dissertation: Evaluation of the potential of the NOAA-n AVHRR reflective data inoceanographyPages: 189 pp.Source: Department of Oceanography, Texas A & M University, College Station, TX,USAKey words: reflective data, advanced very high resolution radiometry, phytoplankton, satelliteobservation, atmospheric effect, albedo, pixel, Coastal Zone Color Scanner,pigment, red tideSummary: The organic and physical features of the ocean surface as seen synoptically canprovide clues to the interactions of those processes governing the ocean. Twosatellite data bases (the NOAA-n Advanced Very High Resolution Radiometer andthe Coastal Zone Color Scanner data) provide the means to compare informationon sea surface phytoplankton concentrations and circulation patterns over a broadarea. In situ data taken during a Florida red tide in 1983 and a Texas red tide in1986 serve to evaluate the relative capabilities of the two satellite data sources.Methods: See "Materials and Methods."QA/QC: N/A (Physical oceanography)121

Contact: Sonia GallegosSource Inst.: Center for Space Research, The University of Texas at Austin, Austin, TX,USAAuthor: Gates, J. A. and Wilson, W. B.Date: 1960Title: The toxicity of Gonyaulax monilata Howell to Mugil cephalusJournal: Limnol. Oceanogr. 5(2):171-174Key words: Gonyaulax monilata, Mugil cephalus, dinoflagellate, toxin, Galveston, Texas, redtideSummary: “Young” mullet (Mugil cephalus) subjected to in vitro cultures of the marine redtide dinoflagellate Gonyaulax monilata suffered mortality within 4.5 hours in allaliquots except the uninoculated control medium. The authors conclude that atoxic substance produced by Gonyaulax monilata was the causative agent.Methods: See “Methods and Materials.”QA/QC: None per se; see “Methods and Materials.”Contact: William B. WilsonSource Inst.: U. S. Fish and Wildlife Service, Galveston, Texas, USAAuthor: Geesey, M. and Tester, P. A.Date: 1993Title/Ch.: Gymnodinium breve: ubiquitous in Gulf of Mexico waters?Book: Toxic Phytoplankton Blooms in the Sea, Proceedings of the Fifth InternationalConference on Toxic Marine PhytoplanktonEditor: T. J. Smayda and Y. ShimizuPages: 251-255Publisher: ElsevierKey words: Gymnodinium breve, Gulf of Mexico, Ptychodiscus brevis, red tide, bloomSummary: A common source of red tide off the west coast of Florida, Gymnodinium breve isfound throughout the Gulf of Mexico, but, until this study, its cell density innearshore and offshore waters of various depths was largely unknown. Overtwelve months (3/90-3/91), NOAA vessels sampled 61 stations throughout theGulf of Mexico from depths of 0 to >150 m. Density in shallow, well-mixedwaters was constant, but in deeper waters with a thermocline, G. breve was moreabundant near the surface. Concentrations in central Gulf waters remained at

Journal: Science 113:250-251Key words: fish mortality, dinoflagellate, bloom, Gulf of Mexico, Florida, Texas, Gonyaulax,Offats BayouSummary: In this lengthy letter to the editors of Science, the author offers some criticism foran article by Connell and Cross in a previous volume in which the two stated that arecent case of fish mortality in Offats Bayou, a branch of Galveston Bay, was likelydue to a red tide of Gonyaulax sp. In addition, Gunter added some historical andscientific data from what little was known of red tides at that time.Methods: None (Letter to editor)QA/QC: N/AContact: N/ASource Inst.: Marine Science Institute, The University of Texas, P. O. Box 1267, Port Aransas,TX 78373-1267 USAAuthor: Gunter, G., Smith, F. G. W., and Williams, R. H.Date: 1947Title: Mass mortality of marine animals on the lower west coast of Florida, November1946-January 1947Journal: Science 105:256-257Key words: fish mortality, Florida, Gulf of Mexico, discolored water, plankton,Summary: From reports of an "odorless but acrid gas" that produced respiratory irritation inan area of heavy surf, the discolored water and corresponding fish kills thatoccurred off the Gulf Coast of South Florida from November of 1946 to Januaryof 1947 was due to Gymnodinium breve, though this article did not identify theorganism to species.Methods: None (report)QA/QC: N/AContact: University of Miami, Coral Gables, Florida, USASource Inst.: SameAuthor: Haddad, K. D. and Carder K. L.Date: 1979Title/Ch.: Oceanic intrusion: one possible initiation mechanism of red tide blooms on thewest coast of FloridaBook: Toxic Dinoflagellate Blooms, Proceedings of the Second International Conferenceon Toxic Dinoflagellate Blooms, Key Biscayne, Florida, Oct. 31-Nov. 5, 1978Editor: D. L. Taylor and H. H. SeligerPages: 269-274Publisher: Elsevier/North-Holland, Inc.Key words: red tide, bloom, Florida, upwelling, Loop Current, cyst, excystment, growthSummary: The authors suggest that the Loop Current’s intrusion onto the west Florida shelfmay resuspend the resting cysts of Gymnodinium breve and create conditionsconducive to excystment and growth. Such conditions include decreasedtemperature, increased light availability and increased nutrients.Methods: N/A (Published hypothesis)QA/QC: N/A123

Contact: Kenneth D. HaddadSource Inst.: Department of Marine Science, University of South Florida, 830 First StreetSouth, St. Petersburg, FL 33701 USAAuthor: Hallegraeff, G. M.Date: 1993Title: A review of harmful algal blooms and their apparent global increaseJournal: Phycologia 32(2):79-99Key words: bloom, red tide, aquaculture, eutrophication, climate, transport, dinoflagellate,cyst, ballast water, shellfishSummary: This review presents evidence for an apparent increase in problem algal blooms inrecent years, though it does not claim to ascribe the trend to an actual increase orto steadily improving means and efforts to detect blooms. Increased recreational,commercial and aquacultural use of coastal waters, however, have yielded moreproblems with negative public health and economic impacts from harmful algalblooms. As a result, the author urges the scientific community to respond to theproblem by making efforts to prevent the spread of harmful algae from the areaswhere they are indigenous to other novel and vulnerable areas throughout theworld and to make public officials aware of policies to prevent or ameliorate thenegative impacts of blooms. The possible impacts of global warming, ozonedepletion, El Nino events, eutrophication and ballast water transport must bestudied with respect to their possible stimulation of blooms.Methods: None (review)QA/QC: N/AContact: G. M. HallegraeffSource Inst.: Department of Plant Science, University of Tasmania, GPO Box 252C, Hobart,Tasmania 7001, AustraliaAuthor: Hallegraeff, G. M. and Bolch, C. J.Date: 1992Title: Transport of diatom and dinoflagellate resting spores in ships' ballast water:implications for plankton biogeography and aquacultureJournal: Journal of Plankton Research 14(8):1067-1084Key words: diatom, dinoflagellate, cyst, ballast water, aquaculture, sediment, Gymnodinium,Alexandrium, bloom, quarantineSummary: Non-endemic diatoms and dinoflagellates may be introduced to novel regions whencargo ships with cyst-contaminated ballast water and associated sedimentsdischarge their ballast water in port. Fifty percent of sediment samples taken from343 cargo vessels in 18 Australian ports revealed dinoflagellate resting spores(cysts); these spores represented at least 53 species, 20 of which were successfullygerminated in the laboratory. Cysts of toxic dinoflagellates of the generaAlexandrium and Gymnodinium were found in 16 ships, one of which contained anestimated >300 million viable A. tamarense cysts. To counter the threat fromtoxic species, the authors suggest several ways to lessen or prevent the spread ofcysts from ballast water discharge.Methods: See "Method."124

QA/QC: None per se; see "Method."Contact: G. M. HallegraeffSource Inst.: Department of Plant Science, University of Tasmania, GPO Box 252C, Hobart,Tasmania 7001, AustraliaAuthor: Harper, D. E., Jr. and Guillen, G.Date: 1989Title: Occurrence of a dinoflagellate bloom associated with an influx of low salinitywater at Galveston, Texas, and coincident mortalities of demersal fish and benthicinvertebratesJournal: Contributions in Marine Science 31:147-161Key words: dinoflagellate, bloom, Galveston, Texas, Atlantic threadfin, Polydactylusoctonemus, hypoxia, hydrogen sulfideSummary: Attempting to correlate hydrographic data with dinoflagellate bloom occurrence tounderstand the sequence of events leading to the bloom, the authors noted thecorrespondence of low salinity water with bloom appearance off Galveston, Texasin early June 1984. The low salinity was likely due to high discharge from theMississippi-Atchafalaya Rivers in preceding months and a wind-driven currentdown the Texas coast. Within a week, a die-off of the demersal Atlantic threadfin(Polydactylus octonemus) occurred, probably due to hypoxia and/or hydrogensulfide production as a result of nocturnal dinoflagellate metabolism and anaerobicdecay of dead dinoflagellate cells.Methods: See “Methods.”QA/QC: None per se; see “Methods.”Contact: Donald E. Harper, Jr.Source Inst.: Texas A & M Marine Laboratory, 5007 Avenue U, Galveston, TX 77551USAAuthor: Hemmert, W. H.Date: 1975Title/Chap.: The public health implications of Gymnodinium breve red tides, a review of theliterature and recent eventsBook: Proceedings of The First International Conference on Toxic DinoflagellateBloomsEditor: V. R. LoCiceroPages: 489-497Publisher:Key words:Summary:The Massachusetts Science and Technology Foundation, Wakefield, MApublic health, Gymnodinium breve, red tide, dinoflagellate, Florida, neurotoxicshellfish poisoning (NSP), respiratory irritation, contact irritation, hemtologicpathology, toxinThe author found the scientific literature depauperate on the public healthproblems caused by G. breve and similar organisms. Southwest Florida's major G.breve red tide event of 1973-74 revealed three major public health concerns and apossible fourth: neurotoxic shellfish poisoning (NSP), respiratory irritation, contactirritation and hematologic pathology. Eleven people were apparently stricken withNSP, though none fatally. Clinical reactions to airborne toxins constituted a125

espiratory irritation that disappeared upon departure from the affected area. Alsotemporary was the contact irritation (mild dermatitis, if any, and/or mild to severeconjunctivitis) experienced by people exposed to the toxin while in the water;severity of conjunctivitis correlates with intensity of exposure. Only the potentialfor decreased blood coagulation exists for humans.Methods: None (report)QA/QC: N/AContact: Wynn H. HemmertSource Inst.: Bureau of Preventable Diseases, Florida State Division of Health, Jacksonville,Florida, USAAuthor: Hofmann, E. E., and Worley, S. J.Date: 1986Title: An investigation of the circulation of the Gulf of MexicoJournal: Journal of Geophysical Research 91(C12):14,221-14.236Key words: circulation, Gulf of Mexico, hydrography, density, Loop Current, mesoscale eddy,Antarctic Intermediate Water, velocity profile, gyre, transportSummary: Reanalysis of historic hydrographic data on winter circulation in the Gulf ofMexico revealed that the large-scale circulation is heavily influenced by ananticyclonic gyre in the upper 500 m. Additional influences come from the LoopCurrent in the eastern gulf and a cyclonic eddy in the northwestern gulf, and thetransports estimated for these circulation features concur with estimates from otherhydrographic studies in the gulf.Methods: See "Methods."QA/QC: N/A (Physical oceanography)Contact: Eileen F. HofmannSource Inst.: Department of Oceanography, Texas A & M University, College Station, TX,USAAuthor: Howell, J. F.Date: 1953Title: Gonyaulax monilata, sp. nov., the causative dinoflagellate of a red tide on the eastcoast of Florida in August-September, 1951Journal: Transactions of the American Microscopical Society 72:153-156Key words: Gonyaulax monilata, dinoflagellate, red tide, Florida, plankton, Offatts Bayou,Galveston, TexasSummary: Using samples mainly from the Indian and Banana Rivers on Florida's east coast,the author described a small dinoflagellate species known to form chains of up to40 cells in length. Some doubt was expressed as to whether it was appropriate toassign the species to the Genus Gonyaulax because the prevalent genericdescription allowed "no variation in the number of precingular plates" and theorganism exhibited radically different thecal suture patterns when compared to G.catenella. In early September of 1952, the author found identical chain-formingdinoflagellates in a sample taken from Offatts Bayou, near Galveston, Texas.Methods: None (taxonomic description/classification)QA/QC: N/A126

Contact: John F. HowellSource Inst.: U. S. Fish and Wildlife Service, Fort Crockett, Galveston, Texas, USAAuthor: Huntley, M., Sykes, P., Rohan, S. and Marin, V.Date: 1986Title: Chemically-mediated rejection of dinoflagellate prey by the copepods Calanuspacificus and Paracalanus parvus: mechanism, occurrence and significanceJournal: Marine Ecology Progress Series 28:105-120Key words: dinoflagellate, copepods, Ptychodiscus brevis, Calanus pacificus, Paracalanusparvus, particle rejection, bloom, chemical defense, growth rateSummary: Thirteen species of dinoflagellates were used as possible prey for two species ofcopepods in a large suite of experiments. Results of one experiment includedPtychodiscus brevis (now called Gymnodinium breve, a source of neurotoxicshellfish poisoning) as one of several dinoflagellates consistently rejected by thecopepod Calanus pacificus. Ingestion of P. brevis cells produced elevated heartrate and loss of motor control in the copepod. Not only do noxious dinoflagellatespecies such as P. brevis gain an interspecific competitive advantage in survivalover edible species, they also seem far more likely to be able to maintain bloomproportions in spite of zooplankton grazers when other factors are favorable.Methods: See “Materials and Methods.”QA/QC: None per se; see “Materials and Methods.”Contact: M. HuntleySource Inst.: Scripps Institution of Oceanography, A-002, La Jolla, California 92093 USAAuthor: Jensen, A. C.Date: 1975Title/Ch.: The economic halo of a red tideBook: Proceedings of The First International Conference on Toxic DinoflagellateBloomsEditor: V. R. LoCiceroPages: 507-516Publisher: The Massachusetts Science and Technology Foundation, Wakefield, MAKey words: red tide, economics, New England, Gonyaulax tamarensis, fishing industry, publichealth, shellfish, halo effect, seafood, seafood industrySummary: An economic halo effect from the 1972 New England red tide of Gonyaulaxtamarensis (source of potentially lethal paralytic shellfish poisoning or PSP)appeared in the form of consumer resistance to canned shellfish and finfishproducts. Shortly after shellfish that had been harvested in New England waterswere removed from the market as a safety measure, consumers in states outside ofNew England refused to buy canned seafood regardless of where it had beenharvested, hurting the seafood industries of states untouched by the red tide. Theauthor concludes with a discussion of the necessary informational system neededto counter the rumors and misinformation that can cause economic havoc forindustries both suffering from and falsely associated with toxic red tide blooms.Methods: None (report)QA/QC: N/A127

Contact: Albert C. JensenSource Inst.: Division of Marine and Coastal Resources, New York State Department ofEnvironmental Conservation, State University of New York at Stony Brook,Stony Brook, New York 11794 USAAuthor: Jensen, D. A. and Bowman, J.Date: 1975Title: On the occurrence of the "red tide" Gonyaulax monilata in the Corpus ChristiInner Harbor (July-September 1975)Pages: 20 pp.Source: Texas Water Quality Board, District 12Key words: red tide, Gonyaulax monilata, Corpus Christi, Texas, bloom, dinoflagellate, cyst,fish kill, iron, Eutreptia c. f. lanowiiSummary: The maximum recorded density of a bloom of Gonyaulax (now Alexandrium)monilata in the Corpus Christi Inner Harbor turning basin was noted when it wasfirst detected by routine monitoring on 22 July 1975. Thereafter, cellconcentrations and the number/length of chains decreased until no red tide wasdetected on 17 September. Despite relatively low cell concentrations, a fish killoccurred in the turning basin on 22 August. The most prominent correlationbetween nutrient and cell concentration concerned iron, which peaked and declinedwith the bloom. A "green tide" occurred immediately after the red tidedisappeared, identified as the euglenoid Eutreptia c. f. lanowii. Benthic cysts aresuggested as the means by which the bloom appeared deep within the inner harbor,though the document offers no evidence of cyst presence.Methods: See "Methods and Materials."QA/QC: None per se but for modified Winkler dissolved oxygen analysis (USEPA, 1974)Contact: James Bowman, Jr.Source Inst.: Texas Natural Resource Conservation Commission, Field Operations Division,Environmental Assessment Program, 4410 Dillon Lane, Suite 47, Corpus Christi,TX 78415-5326 USAAuthor: Joyce, E. A., Jr., and Roberts, B. S.Date: 1975Title/Chap.: Florida Department of Natural Resources Red Tide Research ProgramBook: Proceedings of The First International Conference on Toxic DinoflagellateBloomsEditor: V. R. LoCiceroPages: 95-103Publisher: The Massachusetts Science and Technology Foundation, Wakefield, MAKey words: red tide, Florida, initiation, nutrition, Gymnodinium breve, maintenance, transport,toxin, life cycle, seed bedSummary: About 30 red tides had been reported in Florida waters since 1844, but research oncauses began only in the early 1950's. That research, sponsored by the FloridaDepartment of Natural Resources (FDNR) centered on Gymnodinium breve anddealt with location of bloom initiation, nutrition, hydrologic and meteorologicinfluences on bloom maintenance and transport, effects on offshore patch reef128

iota and inshore shellfish beds, taxonomy and ecology of associatedphytoplankton and bloom prediction. FDNR research at time of publicationemphasized the study of G. breve life cycles, the search for offshore seed beds,toxin longevity and effects on marine life, fisheries repopulation and carcasssalvage, and evaluation of land discharges on bloom growth. The research designemphasized prediction and public education and reduction of negative economicimpact.Methods: None (report)QA/QC: N/AContact: Edwin A. Joyce, Jr.Source Inst.: Florida Department of Natural Resources, Bureau of Marine Science andTechnology, Tallahassee, Florida, USAAuthor: Keller, A. A. and Rice, R. L.Date: 1989Title: Effects of nutrient enrichment on natural populations of the brown tidephytoplankton Aureococcus anophagefferens (Chrysophyceae)Journal: J. Phycol. 25:636-646Key words: brown tide, phytoplankton, Aureococcus anophagefferens, Chrysophyceae,diatoms, mesocosm, Narragansett Bay, Rhode Island, picoalgae, dissolvedinorganic nitrogenSummary: Approximately equal populations of the brown tide picoalga Aureococcusanophagefferens in twelve 13,000 L mesocosms were exposed to varying levels ofnutrients Densities in untreated systems were similar to the increased abundancesof A. anophagefferens in Narragansett Bay (2.6 x 10 9 cells/L max.), the seawatersource for the mesocosms. Nutrient addition tanks also had blooms, but they werebrief in duration and did not long remain at densities above the usual level foreukaryotic algae in the bay. Diatom abundance increased in all nutrient-treatedtanks; that plus a significant inverse correlation between dissolved inorganicnitrogen (DIN) levels and mean picoalgae abundance revealed that the brown tidecan grow at DIN levels known to limit diatom growth.Methods: See “Materials and Methods.”QA/QC: None per se; see “Materials and Methods.”Contact: Aimee A. KellerSource Inst.: Graduate School of Oceanography, University of Rhode Island Bay Campus,South Ferry Road, Narragansett, Rhode Island 92882-1197 USAAuthor: Keller, M. D., Bellows, W. K. and Guillard, R. R. L.Date: 1989Title/Ch.:Book:Editor:Dimethylsulfide production and marine phytoplankton: an additional impact ofunusual bloomsNovel Phytoplankton Blooms: Causes and Impacts of Recurrent Brown Tides andOther Unusual Blooms, Coastal and Estuarine Studies 35E. M. Cosper, V. M. Bricelj and E. J. Carpenter129

Pages: 101-115Publisher: Springer-VerlagKey words: dimethylsulfide, DMS, phytoplankton, bloom, dimethylsulfoniopropionate, DMSP,acrylic acidSummary: Though Aureococcus anophagefferens is only mentioned twice among thenumerous other phytoplankton species responsible for greater or lesser degrees ofDMS release, this paper explains the basic mechanism for that release, its generalenvironmental effect, and the relative contributions to release by specificphytoplankton of twelve classes. A. anophagefferens, as an alga possessingchlorophyll a and c, is grouped with other chrysophytes and diatoms as DMSproducers of species-specific variability, producing less than dinoflagellates andprymnesiophytes, but significantly more than chlorophytes, cryptomonads andcyanobacteria.Methods: See “Methods.”QA/QC: None per se; see “Methods.”Contact: Maureen D. KellerSource Inst.: Bigelow Laboratory for Ocean Sciences, McKown Point, West BoothbayHarbor, Maine 04575 USAAuthor: Kuenstner, S. H.Date: 1988Thesis: The effects of the "brown tide" alga on the feeding physiology of Argopectenirradians and Mytilus edulisPages: 84 pp.Source: Marine Environmental Sciences Program, SUNY at Stony BrookKey words: brown tide, Argopecten irradians, Mytilus edulis, Aureococcus anophagefferens,bloom, chrysophyte, retention efficiency, clearance rate, absorption efficiency,starvationSummary: This study was prompted by brown tide-induced weight loss in adult bay scallopsand recruitment failure during the bloom of 1985. The author studied the feedingmechanism of bay scallops (Argopecten irradians) and mussels (Mytilus edulis) todetermine the adverse effects of the brown tide alga Aureococcus anophagefferenson both bivalves. Scallops had a lower retention efficiency (36%) than mussels(59%) when both grazed on A. anophagefferens. Juvenile scallops and musselshad higher clearance rates for the alga Thalassiosira weissflogii than A.anophagefferens, but both bivalves can digest both algae with 90% efficiencywhen the algae are at low concentrations. Using physiological data to construct anenergy budget for scallops exposed to the brown tide, the results over the shorttermcould not explain the bivalve starvation observed in the field. Chronicexposure, therefore, may have been the key to negative growth during the LongIsland brown tide bloom of 1985.Methods: See "Methods and Materials," pp. 16-31.QA/QC: See "Methods and Materials."Contact: V. Monica BriceljSource Inst.: Marine Sciences Research Center, State University of New York, Stony Brook,NY 11794-5000 USA130

Author: Lowe, J. A., Farrow, D. R. G., Pait, A. S., Arenstam, S. J., and Lavan, E. F.Date: 1991Title: Fish kills in coastal watersPages: pp. 60-61Publisher: National Oceanic and Atmospheric AdministrationKey words: fish, fish-kill, coast, Gulf of Mexico, Texas, red tideSummary: Only one table on p. 61 of this report categorizes fish kills due to red tide in Texasfrom 1980-89, indicating that less than 100 fish died as a result of eight reportedred tide events. [This report is in direct conflict with documented observationalevidence of far greater fish mortality ranging from Galveston Island to south of thePadre Island National Seashore during the period from late August to late October1986. See Trebatoski (1988), among others, listed below.]Methods: None (government report).QA/QC: N/AContact: Strategic Environmental Assessments Division, Office of Ocean ResourcesConservation and Assessment, National Ocean ServiceSource Inst.: National Oceanic and Atmospheric AdministrationAuthor: Lund, E. J.Date: 1936Title/Ch.: Some facts relating to the occurrences of dead and dying fish on the Texas coastduring June, July, and August, 1935Source: Annual Report of the Texas Game, Fish and Oyster Commission, 1934-35Pages: 47-50Publisher: Texas Game, Fish and Oyster CommissionKey words: fish [mortality], Texas, [aerosol irritant], menhaden, mullet, [red tide],[Gymnodinium breve]Summary: This report contains information on a massive fish kill in the summer of 1935,ranging from near Port Aransas (St. Joseph Island) to points from 150 to 200 milessouth. Menhaden and mullet made up the largest percentage of the estimated 2million pounds of dead fish that washed ashore in July and August, accompaniedby at least a dozen other fish species. On several instances, observers reportedexperiencing an "irritating 'gas'," a description which is similar to the effects ofaerosol irritants from Gymnodinium breve toxin. During May and June, prior tothe first appearance of fish carcasses, rainfall and river flood levels were unusuallyhigh, and on 28 August, the surface water temperature was recorded at 31 o C. Theauthor raises those physical factors as potentially important influences on the fishkill, but aside from riverine outflow possibly carrying "heavy inshore planktongrowth," he makes no connection between fish mortality and phytoplankton.Methods: None (Report)QA/QC: N/AContact: Larry McEachron [For access to this literature]Source Inst.: Texas Parks &Wildlife Department, Coastal Fisheries Division, Rockport, TX78382 USA131

Author: Marvin, K. T.Date: 1965Title/Ch.: Operation and maintenance of salt-water laboratoriesSource: Fishery Research: Biological Laboratory, Galveston, Fiscal Year 1964, Circular230Pages: 84-86Publisher: United States Department of the Interior, Fish and Wildlife Service, Bureau ofCommercial FisheriesKey words: East Lagoon (Galveston Bay), plankton, bloom, chlorophyll, Gonyaulax monilata,dinoflagellate,Summary: The USFWS experimental facility in Galveston Bay's East Lagoon had sufferedcomplete mortality of all oyster stock in previous years due to "poisonous planktonblooms" entering the system via the water intake. This led to installation of arecirculating system to temporarily free the system from total dependence on anexterior water source and twice-weekly water analyses for chlorophyll and otherconstituents. An August 1963 chlorophyll peak was linked to a bloom of the redtide dinoflagellate Gonyaulax (now Alexandrium) monilata. The author indicatesthat such blooms seem to be seasonal occurrences in East Lagoon.Methods: None (report)QA/QC: N/AContact: Kenneth T. Marvin, Supervisory ChemistSource Inst.: Bureau of Commercial Fisheries Biological Laboratory, Galveston, Texas, USAAuthor: Matsuoka, K., Fukuyo, Y. and Anderson, D. M.Date: 1989Title/Ch.: Methods for modern dinoflagellate cyst studiesBook: Red tides: biology, environmental science, and toxicology. Proceedings of theFirst International Symposium on Red Tides held November 10-14, 1987, inTakamatsu, Kagawa Prefecture, Japan.Editor: T. Okaichi, D. M. Anderson and T. NemotoPages: 461-479Publisher: Elsevier Science Publishing Company, Inc., New YorkKey words: dinoflagellate, cyst, sampling, fixation, preservation, isolation, culture,identification, Gymnodinium breve, Alexandrium monilataSummary: This manual includes a key for identification of cyst-forming dinoflagellates basedon cyst shape and was the backbone for a dinoflagellate cyst workshop held at thesymposium. Gymnodinium breve and Alexandrium monilata are included in thelist of all extant cyst-forming dinoflagellates.Methods: Primarily a methods paper.QA/QC: None per se.Contact: D. M. AndersonSource Inst.: Biology Department, Woods Hole Oceanographic Inst., Woods Hole, MA 02543USAAuthor: Milligan, A. J.132

Date: 1992Thesis: An investigation of factors contributing to blooms of the “brown tide”Aureococcus anophagefferens (Chrysophyceae) under nutrient saturated (lightlimited) conditionsPages: 84 pp.Source: M. S. Thesis, Department of Marine Environmental Science, State University ofNew York at Stony BrookKey words: bloom, brown tide, Aureococcus anophagefferens, Chrysophyceae, nutrientsaturation, light limitation, Long Island, iron, selenium, nanoplanktonSummary: Following the six-year summer bloom of the brown tide chrysophyte Aureococcusanophagefferens in the bays of Long Island, New York, the author tested thehypothesis that A. anophagefferens had a greater ability to photoacclimate andmaintain high growth rates relative to other phytoplankton. In this attempt, lightutilization efficiency, photoacclimation, carbon metabolism and iron/seleniumeffects were determined for A. anophagefferens. The brown tide alga shows goodphotoacclimation, greater carbon fixation (per unit chlorophyll) and photosyntheticefficiency in fluctuating rather than constant light and enhanced growth withadditions of iron but not selenium.Methods: See “Methods” on pp. 12-20.QA/QC: None per se; see “Methods.”Contact: Elizabeth M. CosperSource Inst.: Marine Sciences Research Center, State University of New York, StonyBrook, NY 11794 USAAuthor: Moestrup, O. and Larsen, J.Date: 1990Title/Ch.: Some comments on the use of the generic names Ptychodiscus and AlexandriumBook: Toxic Marine Phytoplankton, Proceedings of the Fourth International Conferenceon Toxic Marine PhytoplanktonEditor: E. Granéli, B. Sundström, L. Edler and D. M. AndersonPages: 78-81Publisher: Elsevier Science Publishing Co., Inc.Key words: Ptychodiscus brevis, Gymnodinium, Alexandrium, genus, toxic algae, plankton,taxonomy, paralytic shellfish poisoning (PSP), Gonyaulax, flagellatesSummary: The authors argue that the red tide dinoflagellate known as Ptychodiscus brevisshould not be separated from the genus Gymnodinium and that the generic nameAlexandrium is better suited for PSP-producing species formerly placed within thegenus Gonyaulax. Upon these recommendations, the proper nomenclature for oneof the two red tide algae that have constituted problem blooms in the “CoastalBend” of the Texas Gulf coast supports the name Gymnodinium breve.Methods: N/A (Comments on taxonomy)QA/QC: N/AContact: O. MoestrupSource Inst.: Institut for Sporeplanter, Oster Farimagsgade 2D, DK-1353 Kobenhavn K,Denmark133

Author: Montagna, P. A., Stockwell, D. A. and Kalke, R. D.Date: 1993Title: Dwarf surfclam Mulinia lateralis (Say, 1822) populations and feeding during theTexas brown tide eventJournal: Journal of Shellfish Research 12(2):433-442Key words: dwarf surfclam, Mulinia lateralis, Texas, brown tide, chrysophyte, algae, BaffinBay, Laguna Madre, shellfishSummary: Dwarf surfclam populations perished at the same time that a brown tide bloomoccurred in Baffin Bay and Laguna Madre on the Texas Gulf Coast in 1990. Infeeding experiments to determine if the shellfish loss was due to negative feedinginteractions between the clam and the brown tide, radioactive tracers and anadditional three phytoplankton were used. Grazing rates increased with algalconcentrations

Author: Nixon, S. W., Granger, S. L., Taylor, D. I., Johnson, P. W. and Buckley, B. A.Date: 1994Title: Subtidal volume fluxes, nutrient inputs and the brown tide--an alternate hypothesisJournal: Estuarine, Coastal and Shelf Science 39:303-312Key words: nutrients, nutrient flux, brown tide, Aureococcus anophagefferens, Great SouthBay, mesocosmsSummary: This paper agrees that unusual meteorological and hydrological conditionscontributed the the 1985 outbreak of brown tide in Long Island bays, but proposesthat, with a many-fold greater contribution of nutrients from the coastal oceanrelative to land drainage, A. anophagefferens achieved bloom proportions becausenutrient input was reduced, not increased. Evidence from field surveys andmesocosms suggest that oligotrophic waters favor the growth of A.anophagefferens.Methods: N/A (Published hypothesis)QA/QC: N/AContact: S. W. NixonSource Inst.: Graduate School of Oceanography, Univeristy of Rhode Island, Narragansett,Rhode Island 02882-1197 USAAuthor: Nuzzi, R. and Waters R. M.Date: 1989Title/Ch.: The spatial and temporal distribution of “brown tide” in eastern Long IslandBook: Novel Phytoplankton Blooms: Causes and Impacts of Recurrent Brown Tides andOther Unusual Blooms, Coastal and Estuarine Studies 35Editor: E. M. Cosper, V. M. Bricelj and E. J. CarpenterPages: 117-137Publisher: Springer-VerlagKey words: distribution, brown tide, Long Island, bloom, phytoplankton, AureococcusanophagefferensSummary: The Suffolk County Department of Health Service’s “Bureau of MarineResources” reports on its investigations into the distribution of the brown tidefrom 1986-1988. Areas affected by brown tide, the Peconic Bay estuary and theSouth Shore bays as seen during aerial surveys, remained relatively constant, andboth unusually large and persistent over the three years covered by this study.Brown tide abundance seemed to be unlinked to macronutrient concentrations inthe affected areas, with regional meterorological conditions a more likely catalyst,particularly rainfall fluctuations. Micronutrient concentrations in bloom watersmay also be a principal agent of bloom formation.Methods: See “Methods.”QA/QC: None per se; see “Methods” and “Results.”Contact: Robert NuzziSource Inst.: Suffolk County Department of Health Services, Evans K. Griffing County Center,Riverhead, New York 11901 USAAuthor: Olsen, P. S.Date: 1989135

Title/Ch.: Development and distribution of a brown-water algal bloom in Barnegat Bay, NewJersey with perspective on resources and other red tides in the regionBook: Novel Phytoplankton Blooms: Causes and Impacts of Recurrent Brown Tides andOther Unusual Blooms, Coastal and Estuarine Studies 35Editor: E. M. Cosper, V. M. Bricelj and E. J. CarpenterPages: 189-212Publisher: Springer-VerlagKey words: brown-water, bloom, Barnegat Bay, new Jersey, red tide, phytoplankton,Aureococcus anophagefferens, picoplanktonSummary: The authors conducted a 1987 survey of a persistent yellow-brown algal bloom inBarnegat Bay, New Jersey, that had returned in high density every summer since1985, seeking to accurately characterize the responsible picoplankton and revealpotential similarities between it and the simultaneous brown tide in Long Islandand the New York Bight region. The 2-3 µm coccoid alga at densities as high asseveral times 10 6 cells/ml could not be identified as a common bloom-producingchlorophyte nor the chrysophyte Aureococcus anophagefferens, among others,and greatly reduced algal diversity at peak bloom. High densities seldom coincidedwith chlorophyll maxima, but a trend of higher numbers with increasing salinitywas observed. Unofficial reports of reduced eelgrass survival and sportfishingcatches came from areas affected by the bloom.Methods: See “Methods.”QA/QC: None per se; see “Methods.”Contact: Paul S. OlsenSource Inst.: New Jersey State Dept. of Environmental Protection, Division of WaterResources, Geological Survey, CN 029, Trenton, New Jersey 08625 USAAuthor: Perry, H. M., Stuck, K. C., and Howse, H. D.Date: 1979Title: First record of a bloom of Gonyaulax monilata in coastal waters of MississippiJournal: Gulf Research Reports 6(3):313-316Key words: bloom, Gonyaulax [Alexandrium] monilata, Mississippi Sound, dinoflagellate,Gulf of Mexico, red tideSummary: Aerial surveys and water samples were performed during a widespread bloom ofthe armored dinoflagellate Gonyaulax [now Alexandrium] monilata in MississippiSound as well as Alabama and Florida. The bloom persisted in Mississippi Soundfrom about 8 August until the advent of Hurricane Frederic on 11 September(1979). During the bloom, surface temperatures ranged from 30.0 to 30.8 o C.Salinities were below normal in Mississippi Sound due to previous heavy rains andranged from 24.0 to 26.0 ppt. The maximum cell count reached 1.65 x 10 7cells/liter on 22 August. Pensacola Bay, Florida, had the maximum cell density forthat state of 3.18 x 10 7 cells/liter on 15 August, when water temperature was28.0 o C and salinity only 14.0 ppt.Methods: See "Materials and Methods."QA/QC: None per se; see "Materials and Methods."Contact: Harriet M. Perry136

Source Inst.: Fisheries Research and Development, Gulf Coast Research Laboratory, OceanSprings, MS 39564 USAAuthor: Pierce, R. H., Henry, M. S., Proffitt, L. S. and Hasbrouck, P. A.Date: 1990Title/Ch.: Red tide toxin (brevetoxin) enrichment in marine aerosolBook: Toxic Marine Phytoplankton, Proceedings of the Fourth International Conferenceon Toxic Marine PhytoplanktonEditor: E. Granéli, B. Sundström, L. Edler and D. M. AndersonPages: 128-131Publisher: ElsevierKey words: red tide, toxin, brevetoxin, aerosol, dinoflagellate, Ptychodiscus brevisSummary: Knowing that marine aerosols can carry brevetoxins, the authors measured thelevel of toxin enrichment in aerosols created in the laboratory versus originalculture concentrations. A total of six toxins were detected in both culture andaerosol, enriched by 5 to 50 times in the aerosol relative to the culture.Methods: See “Methods and Materials.”QA/QC: None per se; see “Materials and Methods.”Contact: Richard H. PierceSource Inst.: Mote Marine Laboratory, 1600 City Island Park, Sarasota, FL 34236 USAAuthor: Proctor, R. R., Jr.Date: 1965Title/Ch.: Special Report: Biological Indicators in East Lagoon, Galveston IslandSource: Fishery Research: Biological Laboratory, Galveston, Fiscal Year 1964, Circular230Pages: 87-88Publisher: United States Department of the Interior, Fish and Wildlife Service, Bureau ofCommercial FisheriesKey words: East Lagoon, [Galveston Bay], oyster, oyster mortality, Gonyaulax monilata, [redtide, dinoflagellate], bloomSummary: The author reports on the first two years of a study by the Bureau of CommercialFisheries to determine if water in the East Lagoon was suitable for oyster culture.An August, 1963 bloom of Gonyaulax [now Alexandrium] monilata compelledthe transfer of oysters kept in East Lagoon into the laboratory tank with acorresponding group of oysters kept there and the conversion of the tankcirculation to a closed, recirculating system. Both oyster groups still sufferedmortality thereafter (10 of the lagoon group's original 25 oysters; 2 out of 25 in thelaboratory group); the author suggests that G. monilata cells were in therecirculated water and caused the mortality. The bloom ceased in the lagoon afterabout two weeks, and the lagoon oysters were returned to the field. No furthermortality was associated with G. monilata.Methods: None (report)QA/QC: N/AContact: Raphael R. Proctor, Jr., ChemistSource Inst.: Bureau of Commercial Fisheries Biological Laboratory, Galveston, Texas, USA137

Author: Proctor, R. R., Jr.Date: 1966Title/Ch.: Special Report: Oyster growth experiment in East LagoonSource: Annual Report of the Bureau of Commercial Fisheries Biological Laboratory,Galveston, Texas, Fiscal Year 1965, Circular 246Pages: 48-49Publisher: United States Department of the Interior, Fish and Wildlife Service, Bureau ofCommercial FisheriesKey words: oyster, oyster mortality, East Lagoon, [Galveston Bay], Gonyaulax monilata,[dinoflagellate, red tide]Summary: The author states that conditions in a USFWS lagoon and the associated lagoonlaboratory are suitable only for short-term oyster experiments due to a commonoyster disease caused by Dermocystidium marinum and apparent annual (summer)blooms with subsequent oyster mortality due to the red tide dinoflagellateGonyaulax [now Alexandrium] monilata.Methods: None per se (special report)QA/QC: N/AContact: R. R. Proctor, Jr., ChemistSource Inst.: Bureau of Commercial Fisheries Biological Laboratory, Galveston, Texas, USAAuthor: Quick, J. A., Jr., and Henderson, G. E.Date: 1975Title/Chap.: Evidences of new ichtyointoxicative phenomena in Gymnodinium breve red tidesBook: Proceedings of The First International Conference on Toxic DinoflagellateBloomsEditor: V. R. LoCiceroPages: 413-422Publisher: The Massachusetts Science and Technology Foundation, Wakefield, MAKey words: ichthyotoxin, Gymnodinium breve, red tide, dinoflagellate, Florida, fishes, distressbehavior, necropsy, neurointoxication, chronic tissue damageSummary: The west coast of Florida's peninsula suffered an extended red tide from October1973 through June 1974. Necropsies were performed as quickly as possible on129 fish of fifteen genera and species that were either severely distressed or freshlydead at time of collection. Sixteen pathologies were consistently observed; somefish perished due to neurointoxication, whereas other species succumbed tochronic tissue damage. General symptoms were dehydration, hemolysis anddisrupted blood clotting mechanisms. Distress behavior was marked and couldwell be diagnostic for some species.Methods: See "Methods and Materials."QA/QC: None per se; see "Methods and Materials."Contact: J. A. Quick, Jr.Source Inst.: Florida Department of Natural Resources, Marine Research laboratory, St.Petersburg, Florida, USAAuthor: Ray, S. M. and Wilson, W. B.138

Date: 1957Title: Effects of unialgal and bacteria-free cultures of Gymnodinium brevis on fish , andnotes on related studies with bacteriaJournal: USFW Service Fishery Bulletin 123(57):469-496Key words: unialgal culture, Gymnodinium brevis, fish, bacteria, dinoflagellate, Gulf ofMexico, red tide, toxinSummary: With a goal to (1) conduct a laboratory study complementary to field studies ofmarine animal mortality due to Gymnodinium brevis red tide [sp. now referred toas G. breve] and (2) increase understanding of why such mass mortalities occur,the authors used unialgal and bacteria-free G. brevis cultures to test for toxiceffects on fish. Given that fish mortality in bacteria-free cultures did not differ intoxicity from unialgal cultures, the authors concluded that G. brevis does producea toxic substance directly responsible for mass mortality of marine animals duringblooms in the Gulf of Mexico. Furthermore, this substance does not lose toxicitywith the death or even the absence of the G. brevis cells. The six fish speciestested were differentially sensitive to the toxin.Methods: See methods described within the body of the paper with respect to eachexperiment.QA/QC: None per se; see the descriptions of methods in the body of the paper.Contact: Sammy M. RaySource Inst.: Marine Laboratory, Texas A & M University, Galveston, TXAuthor: Ray, S. M. and Aldrich, D. V.Date: 1967Title/Ch.: Ecological interactions of toxic dinoflagellates and molluscs in the Gulf of MexicoBook: Animal ToxinsEditor: F. Russell and P. SaundersPages: 75-83Publisher: Pergamon Press, NYKey words: toxin, dinoflagellate, mollusc, Gulf of Mexico, Gymnodinium breve, Gonyaulaxmonilata, Florida, TexasSummary: The authors investigate several hypotheses as to why red tide dinoflagellates in theGulf of Mexico have not caused comparable harm to its large shellfish industry asother species have to those of the Atlantic and Pacific coasts. Cultures ofGymnodinium breve and Gonyaulax monilata [preferably called Alexandriummonilata], both Gulf species responsible for fish kills, were introduced into oystercultures. The oysters were then fed to chicks, but poisoning in the chicks onlyoccurred with G. breve. Oysters and other shellfish did not filter when exposed toG. monilata in laboratory culture, a behavior apparently identical to wildpopulations exposed to natural G. monilata blooms in situ. Differing toxic effectsbetween the two dinoflagellates were observed in molluscs, a polychaete and fish.G. breve blooms may be too infrequent to severely affect commercial shellfish inthe Gulf, and Gulf shellfish avoid any negative effects of G. monilata by notfiltering.Methods: See “Materials and Methods.”QA/QC: None per se; see “Materials and Methods.”139

Contact: Sammy M. RaySource Inst.: Marine Laboratory, Texas A & M University, Galveston, TXAuthor: Riley, C. M., Holt, S. A., Holt, G. J., Buskey, E. J. and Arnold, C. R.Date: 1989Title: Mortality of larval red drum (Sciaenops ocellatus) associated with a Ptychodiscusbrevis red tideJournal: Contributions in Marine Science 31:137-146Key words: larvae, red drum, Sciaenops ocellatus, dinoflagellate, Ptychodiscus brevis, redtide, Texas, recruitmentSummary: Ptychodiscus brevis, preferably known as Gymnodinium breve, is a red tidedinoflagellate that can cause paralysis and death in laboratory-spawned and wildcaughtred drum larvae at all concentrations above 40 cells/ml. A fall outbreak ofthis red tide on the Texas Gulf coast in 1986 achieved average peak densities of7000 cells/ml, but concentrations of almost 5 x 10 4 cells/ml were detected inisolated patches in bays near Port Aransas throughout October. Red tide bloomsof this sort can reduce red drum recruitment during spawning periods.Methods: See “Methods.”QA/QC: None per se; see “Methods.”Contact: Cecelia M. RileySource Inst.: University of Texas at Austin, Marine Science Institute, Port Aransas, TX 78373-1267Author: Roberts, B. S.Date: 1979Title/Ch.: Occurrence of Gymnodinium breve red tides along the west and east coasts ofFlorida during 1976 and 1977Book: Toxic Dinoflagellate Blooms, Proceedings of the Second International Conferenceon Toxic Dinoflagellate Blooms, Key Biscayne, Florida, Oct. 31-Nov. 5, 1978Editor: D. L. Taylor and H. H. SeligerPages: 199-202Publisher: Elsevier/North-Holland, Inc.Key words: Gymnodinium breve, red tide, Florida, bloomSummary: Red tides in 1976 and 1977 were analyzed with regard to their most likely meansof initiation, support and maintenance, all three progressing in a predictablefashion. In 1976, for instance, surface concentrations of G. breve increasedgradually offshore, were then transported inshore and, after winds inducedmovement to the south, gradually dissipated. Movement and increasedconcentrations could be attributed to winds and currents.Methods: See “Methods.”QA/QC: None per se; see “Methods.”Contact: Beverly S. RobertsSource Inst.: Florida Department of Natural Resources, Marine Research Laboratory, 100Eighth Ave. S. E., St. Petersburg, FL 33701 USAAuthor: Roberts, B. S., Henderson, G. E. and Medlyn, R. A.140

Date: 1979Title/Ch.: The effect of Gymnodinium breve toxin(s) on selected mollusks and crustaceansBook: Toxic Dinoflagellate Blooms, Proceedings of the Second International Conferenceon Toxic Dinoflagellate Blooms, Key Biscayne, Florida, Oct. 31-Nov. 5, 1978Editor: D. L. Taylor and H. H. SeligerPages: 419-424Publisher: Elsevier/North-Holland, Inc.Key words: Gymnodinium breve, toxin, mollusk, crustacean, Fasciolaria hunteria, Melongenacorona, Oliva sayana, Callinectes sapidus, Menippe mercenaria, red tideSummary: The toxin or toxins of the red tide dinoflagellate Gymnodinium breve adverselyaffected three species of mollusks (Fasciolaria hunteria, Melongena corona andOliva sayana) when directly exposed to G. breve toxins (55-69% mortality over48 hrs.), but had no affect on two species of crustacean (Callinectes sapidus andMenippe mercenaria) when all crab species were fed toxic clam meat. Along witha lack of any mortality, the crab tissue, upon analysis, showed no accumulation ofthe toxin.Methods: See “Methods and Materials.”QA/QC: None per se; see “Methods and Materials.”Contact: Beverly S. RobertsSource Inst.: Florida Department of Natural Resources, Marine Research Laboratory, 100Eighth Ave. S. E., St. Petersburg, FL 33701 USAAuthor: Roszell, L. E., Schulman, L. S. and Baden, D. G.Date: 1990Title/Ch.: Toxin profiles are dependent on growth stages in cultured Ptychodiscus brevisBook: Toxic Marine Phytoplankton, Proceedings of the Fourth International Conferenceon Toxic Marine PhytoplanktonEditor: E. Granéli, B. Sundström, L. Edler and D. M. AndersonPages: 403-406Publisher: ElsevierKey words: toxin, growth, Ptychodiscus brevis, red tide, dinoflagellateSummary: Characterization from over 3000 liters of batch cultures of the various toxins, allvery similar, produced by Ptychodiscus brevis (now known as Gymnodiniumbreve) during logarithmic, stationary and declining phases of population growthreveals that the eight possible toxins appear individually or in combination atdifferent times in the life of a population. What the authors do not suggest butwhat seems obvious is extension of these findings to characterization of the overallgrowth stage of blooms in situ.Methods: See “Experimental” and “Results.”QA/QC: None per se; see “Experimental.”Contact: Laurie E. RoszellSource Inst.: University of Miami Rosenstiel School of Marine and Atmospheric Science,Division of Biology and Living Resources, 4600 Rickenbacker Causeway, Miami,FL 33149 USAAuthor: Rounsefell, G. A., and Nelson, W. R.141

Date: 1966Title: Red-tide research summarized to 1964 including an annotated bibliographyPages: 85 pp.Source: United States Fish and Wildlife Service Special Scientific Report, Fisheries No.535, Washington, D. C.Key words: red tide, Florida, bloom, mortality, plankton, dinoflagellate, toxic, Gymnodiniumbreve, Gulf of Mexico, TexasSummary: Using published and unpublished data, the authors summarize the status of red tideresearch in Florida up to 1964, listing 292 references with some annotations, anddiscuss the influence of oceanographic conditions on blooms, seasonal and coastaldistribution of the Florida red tide and progress in various research efforts.Emphasis is upon Gymnodinium breve.Methods: None (research summary)QA/QC: N/AContact: Tom SerotaSource Inst.: U. S. Fish and Wildlife Service, Fisheries Resources Office, 6300 Ocean Dr.,Corpus Christi, Texas 78412 USAAuthor: Sandgren, C. D.Date: 1983Title/Chap.: Survival strategies of chrysophycean flagellates: reproduction and the formationof resistant resting cystsBook: Survival strategies of the algaeEditor: G. A. FryxellPages: Pp. 23-48Publisher: Cambridge University Press, CambridgeKey words: chrysophytes, flagellates, survival strategy, reproduction, resting cyst, microalgae,resting stage, statospore, phytoplankton, life historySummary: Many phytoplankton have resistant resting stages (cysts) as a necessary componentof their life history strategy, enabling them to outlast unfavorable environmentalconditions until recolonization of the plankton is possible. These strategies existfor both freshwater and marine phytoplankton. Freshwater chrysophytes known asgolden algae are very seasonal species and use a siliceous resting cyst known as astatospore. The statospore is the primary subject of the review paper, whichcovers its development, surface morphology, and responses to factors influencingencystment, both in individual cells and populations. The author also refers earlyin the review to several general reference texts in phycology that address restingcysts in marine chrysophytes.Methods: None per se (Review article)QA/QC: N/AContact: Craig D. SandgrenSource Inst.: Department of Biology, University of Texas at Arlington, Arlington, TX 76019Author: Seliger, H. H., Tyler, M. A. and McKinley, K. R.Date: 1979Title/Ch.: Phytoplankton distributions and red tides resulting from frontal circulation patterns142

Book: Toxic Dinoflagellate Blooms, Proceedings of the Second International Conferenceon Toxic Dinoflagellate Blooms, Key Biscayne, Florida, Oct. 31-Nov. 5, 1978Editor: D. L. Taylor and H. H. SeligerPages: 239-248Publisher: Elsevier/North-Holland, Inc.Key words: phytoplankton, distribution, red tide, frontal circulation, Gymnodinium breve,Florida, Prorocentrum mariae lebouriae, Chesapeake BaySummary: This paper extrapolates conditions existing for blooms of Prorocentrum mariaelebouriae in Chesapeake Bay with the west Florida red tides of Gymnodiniumbreve and that of another species in New England. Conditions promoting red tidesinclude (1) downward movement of surface concentrations of red tidedinoflagellates resulting from wind and/or tidal influences, (2) transport to depthand toward shallow waters, (3) upwelling into the photic zones of shallow watersand (4) concentration into wind- or tide-driven convergences at the surface,producing dense surface patches. A specific scenario is included for each of thethree locales.Methods: N/A (Published hypothesis)QA/QC: N/AContact: Howard H. SeligerSource Inst.: McCollum-Pratt Institute and Department of Biology, The Johns HopkinsUniversity, Baltimore, MD 21218 USAAuthor: Shanley, E. and Vargo, G. A.Date: 1990Title/Ch.: Cellular composition, growth, photosynthesis, and respiration rates ofGymnodinium breve under varying light levelsBook: Toxic Marine Phytoplankton, Proceedings of the Fourth International Conferenceon Toxic Marine PhytoplanktonEditor: E. Granéli, B. Sundström, L. Edler and D. M. AndersonPages: 831-836Publisher: ElsevierKey words: growth, photosynthesis, respiration, Gymnodinium breve, chlorophyll a,chlorophyll c, carotenoidSummary: Laboratory cultures of Wilson’s clone of the red tide dinoflagellate Gymnodiniumbreve were adapted to the full range of light available in situ in an attempt tomeasure and compare any variations in cellular composition, growth rates,respiration rates and rates of photosynthesis. Results indicated a proportionalincrease between photosynthesis and growth rates over a range of irradiance equalto about 2% to 16% of surface irradiance. The study’s purpose was to clarify thelow light response for Gymnodinium breve populations in offshore waters atdepths of 20-30 m, where light levels can be as low as 2% of the mean dailyincident irradiance and where bloom initiation is hypothesized. Findings revealthat offshore populations at such depths may indeed serve as seed populations forblooms.Methods: See “Methods.”QA/QC: None per se; see “Methods.”143

Contact: Evanne ShanleySource Inst.: Department of Marine Science, University of South Florida, 140 Seventh AvenueSouth, St. Petersburg, FL 33701 USAAuthor: Shormann, D. E.Date: 1992Thesis: The effects of freshwater inflow and hydrography on the distribution of brown tidein south Texas baysPages: 111 pp.Source: M. A. Thesis, Department of Marine Science, The University of Texas at Austin.Key words: hydrography, brown tide, Texas, nitrate, Copano Bay, residence time, phosphate,ammonium, nitrite, silicateSummary: The author created an equation to predict mean bay salinity and determine ifCopano Bay mixing processes werre dominated by freshwater influx, tidal mixingor a combination thereof. A second equation was created to gauge residence timefrom freshwater inflow. Phytoplankton growth (including brown tide) did notappear to be either N- or P-limited. Mean chlorophyll concentrations weresignificantly correlated with with particulate carbon and nitrogen and thus from insitu phytoplankton production. A growth rate of the brown tide was only 0.14day -1 . Copano Bay was eutrophic with respect to phosphorus and had a N/P ratioidentical to fertilizer ratios used by local farmers. The mean residence andresponse times of Copano Bay were similar to Baffin Bay and about one order ofmagnitude greater than Nueces Bay. Such low water circulation could well aidpersistence of the brown tide in those bays; notably, Nueces Bay is rarely affectedby any algal bloom.Methods: See “Methods” on pp. 18-25 and p. 94.QA/QC: None per se; see “Methods.”Contact: Terry E. WhitledgeSource Inst.: The University of Texas Marine Science Institute, P. O. Box 1267, Port Aransas,TX 78373-1267Author: Shumway, S. E.Date: 1990Title: A review of the effects of algal blooms on shellfish and aquacultureJournal: Journal of the World Aquaculture Society 21(2):65-104Key words: toxic algae, bloom, shellfish, aquaculture, dinoflagellates, Gymnodinium breve,Ptychodiscus brevis, Gonyaulax monilata, Aureococcus anophagefferensSummary: This review paper comments on worldwide toxic algal blooms, presents thecommercial management possibilities for coping with such blooms and suggestsmeans of efficiently and successfully using marine resources in spite of theinstability caused by blooms. Included are the two red tide dinoflagellatesresponsible for problem blooms along the Texas Gulf Coast and a brown tidechrysophyte similar to the organism that began blooming in the Laguna Madre in1990.Methods: N/A (Review paper)QA/QC: N/A144

Contact: Sandra E. ShumwaySource Inst.: Maine Department of Marine Resources and Bigelow Laboratory for OceanSciences, West Boothbay Harbor, Maine 04575 USAAuthor: Siddall, S. E.Date: 1987Title: Climatology of Long Island related to the "brown tide" phytoplankton blooms of1985 and 1986Pages: 16 pp.Publisher: Marine Sciences Research Center, SUNY, Stony Brook, NYKey words: climatology, Long Island, brown tide, phytoplankton, bloom, meteorology,precipitationSummary: Using long-term records to indicate prevailing trends over months or years forLong Island and short-term (daily) records of weather events for 1984-86 for fivestations among East End bays, climatological/meterorological data were matchedwith brown tide cell counts in an effort to discover trends and suggest causativefactors for the bloom during those two years. No significant anomalies intemperature, precipitation, wind or daily radiation could be associated with browntide initiation or maintenance. Long Island experienced a moderate to severedrought when the first bloom occurred in 1985, but the report emphasizes that themere existence of drought beforehand says nothing about true underlying causesfor the bloom and cannot be considered statistically valid. A hypothesis of bloomformation and persistence can, however, be linked to precipitation and resultingterrestrial runoff or groundwater effects during an otherwise dry period.Methods: N/A (Report)QA/QC: N/AContact: Scott E. SiddallSource Inst.: Marine Sciences Research Center, State University of New York, StonyBrook, NY 11794-5000Author: Sieburth, J. McN., Johnson, P. W. and Hargraves, P. E.Date: 1988Title: Ultrastructure and ecology of Aureococcus anophagefferens Gen. et sp. nov.(Chrysophyceae): the dominant picoplankter during a bloom in Narragansett Bay,Rhode Island, summer 1985Journal: J. Phycol. 24:416-425Key words: ultrastructure, ecology, Aureococcus anophagefferens, Chrysophyceae,picoplankton, bloom, Narragansett Bay, Rhode Island, Synechococcus Nägeli,Calycomonas ovalisSummary: The unknown 2 um diameter chrysophyte herein described as the novel speciesAureococcus anophagefferens first came to the authors attention with thecessation of feeding in filter feeders exposed to Narragansett Bay seawater and adensity of 10 9 cell/L. Neither phase contrast nor epifluorescence microscopy coulddiscriminate the chrysophyte from similar sized phytoplankton, though examinationof thin sections with transmission electron microscopy was successful. About 300attempts to culture the alga with twelve different culture media were unsuccessful.145

Methods: See “Materials and Methods.”QA/QC: None per se; see “Materials and Methods.”Contact: John McN. SieburthSource Inst.: Graduate School of Oceanography, University of Rhode Island Bay Campus,South Ferry Road, Narragansett, Rhode Island 02882-1197 USAAuthor: Sieburth, J. McN. and Johnson, P. W.Date: 1989Title/Ch.: Picoplankton ultrastructure: a decade of preparation for the brown tide alga,Aureococcus anophagefferensBook: Novel Phytoplankton Blooms: Causes and Impacts of Recurrent Brown Tides andOther Unusual Blooms, Coastal and Estuarine Studies 35Editor: E. M. Cosper, V. M. Bricelj and E. J. CarpenterPages: 1-21Publisher: Springer-VerlagKey words: picoplankton, ultrastructure, brown tide, Aureococcus anophagefferens,transmission electron microscopy, TEMSummary: In an effort to determine the trophic definition of pico- and nanoplankton, theauthors developed a TEM process to examine thin sections of cells in the naturallyoccurring populations of uncultured seawater samples. With success depending oncells possessing unique ultrastructural characteristics, the authors, after a decade ofsuch work on samples from Narragansett Bay, were in a unique position toexamine samples of brown tide upon bloom occurrence there, beginning in 1985.Their timely sampling incriminated Aureococcus anophagefferens as the algaresponsible for cessation of filter feeding during the bloom’s peak. Reexaminationof previous samples several years before the initial brown tide bloomrevealed A. anophagefferens as a likely normal component of the picoplankton.Many such picoalgae probably remain unindentified.Methods: See “Methods.”QA/QC: None per se; see “Methods.”Contact: John McN. SieburthSource Inst.: Graduate School of OceanographyUniversity of Rhode Island, Narragansett, RI 92882-1197 USAAuthor: Sievers, A. M.Date: 1969Title: Comparative toxicity of Gonyaulax monilata and Gymnodinium breve to annelids,crustaceans, molluscs and a fishJournal: Journal of Protozoology 16(3):401-404Key words: toxicity, Gonyaulax monilata, Gymnodinium breve, annelid, crustacean, mollusc,fish, dinoflagellate, mortality, toxin,Summary: Several kinds of marine animals were exposed to concentrations of twodinoflagellate cultures from undiluted to 90% dilution over 48 hours in order todetermine toxicity of the two toxins in terms of mortality. Fish were equallysensitive to both Gonyaulax monilata [preferably known as Alexandrium146

monilata] and Gymnodinium breve toxins, crustaceans were resistant to both, andboth annelids and molluscs were more sensitive to G. monilata toxin.Methods: See “Methods.”QA/QC: None per se; see “Methods.”Contact: Anita M. SieversSource Inst.: Marine Laboratory, Texas A&M University, Galveston, TX 77550Author: Smayda, T. J. and Fofonoff, P.Date: 1989Title/Ch.: An extraordinary, noxious brown-tide in Narragansett Bay. II. Inimical effects.Book: Red tides: biology, environmental science, and toxicology. Proceedings of theFirst International Symposium on Red Tides held November 10-14, 1987, inTakamatsu, Kagawa Prefecture, Japan.Editor: T. Okaichi, D. M. Anderson and T. NemotoPages: 133-136Publisher: Elsevier Science Publishing Company, Inc., New YorkKey words: brown tide, Narragansett Bay, bloom, Aureococcus anophagefferens (appears asA. anorexefferens), zooplankton, Mytilus edulis, anchovy, kelp, benthic larvae,Acartia tonsaSummary: The density of an A. anophagefferens bloom was strongly and negativelycorrelated (-0.91) with density of the predominant copepod Acartia tonsa; A.tonsa adult females fed the brown tide alga suffered lower feeding rates, eggproduction and body weight. Compared to 1984 and 1986, the 1985 bloomcorresponded with a 60-fold lower mean cladoceran abundance. Natural musselbeds lost 30%-100% of their populations, apparently due to starvation,substantiated by cessation of filtering in laboratory-raised mussels at brown tidealgal densities exceeded 500 x 10 6 cells/liter. Laminarian kelp died when theeuphotic zone mussels to which they were attached also died and sank to deeperwaters. Aureococcus abundance was also negatively correlated with benthic larvalnumbers (r = -0.58). Polychaete and bivalve larvae and bay anchovy eggs were alllower than normal (1.5x, 3.6x and 10x lower, resp.) as was zooplankton andbenthic grazing.Methods: None (Review paper)QA/QC: N/AContact: Theodore J. SmaydaSource Inst.: Graduate School of Oceanography, University of Rhode Island, Kingston, RhodeIsland 02881 USAAuthor: Smayda, T. J. and Villareal, T. A.Date: 1989Title/Ch.: An extraordinary, noxious brown-tide in Narragansett Bay. I. The organism andits dynamics.Book: Red tides: biology, environmental science, and toxicology. Proceedings of theFirst International Symposium on Red Tides held November 10-14, 1987, inTakamatsu, Kagawa Prefecture, Japan.Editor: T. Okaichi, D. M. Anderson and T. Nemoto147

Pages: 129-132Publisher: Elsevier Science Publishing Company, Inc., New YorkKey words: brown tide, Narragansett Bay, bloom, chrysophyte, Aureococcus anophagefferensSummary: The A. anophagefferens bloom during May-September 1985 in Narragensett Bayproduced densities as high as 1.2 x 10 9 cells/liter; mean abundance was stronglycorrelated (r = 0.98) with the observed salinity gradient, though authors suggestthat salinity per se was not a causative factor. Neither was eutrophication, forstrong inverse correlations appeared between mean abundance and "ammoniumplus nitrate" and phosphate concentrations (-0.76 and -0.62, resp.). Diatoms,dinoflagellates, microflagellates and euglenids bloomed concurrently andextensively, with euglenids persisting through November once the brown tidebloom disappeared. Authors postulate that simultaneous brown tide blooms inLong Island and New Jersey indicate a mesoscale scenario associated withclimatologic/hydrographic conditions. Spring increases in quantity or duration oflight and concentrations of phagotrophic flagellates may be bloom catalysts.Methods: None specified. See “Materials and Methods.”QA/QC: None. See “Materials and Methods.”Contact: Theodore J. SmaydaSource Inst.: Graduate School of Oceanography, University of Rhode Island, Kingston, RhodeIsland 02881 USAAuthor: Smayda, T. J. and Villareal, T. A.Date: 1989Title/Ch.: The 1985 ‘brown-tide’ and the open phytoplankton niche in Narragansett Bayduring summerBook: Novel Phytoplankton Blooms: Causes and Impacts of Recurrent Brown Tides andOther Unusual Blooms, Coastal and Estuarine Studies 35Editor: E. M. Cosper, V. M. Bricelj and E. J. CarpenterPages: 159-187Publisher: Springer-VerlagKey words: brown tide, phytoplankton, Narragansett Bay, chrysophyte, Aureococcusanophagefferens, bloom, nicheSummary: The authors call attention to the lack of information on the presence andabundance of other phytoplankton species before, during and after a bloom andsuggest that such information may be crucial to a complete understanding ofbloom dynamics. Smaller-scale but significant blooms of several diatom,dinoflagellate and other phytoflagellate species (a total of 14 other taxa) cooccurredwith and/or followed the major A. anophagefferens bloom at differenttimes and for various durations during May-October 1985 in Narragensett Bay.As a result, one may view blooms of these other taxa after the A. anophagefferensbloom ceased as exploitations of the niche previously dominated by A.anophagefferens. Future blooms should not be considered monospecific unless soproven.Methods: See “Methods.”QA/QC: None per se; see “Methods.”Contact: Theodore J. Smayda148

Source Inst.: Graduate School of Oceanography, University of Rhode Island, Kingston, RhodeIsland 02881 USAAuthor: Snider, R. (ed.)Date: 1987Title: Red tide in Texas: an explanation of the phenomenonPages: 4 pp.Publisher: Marine Information Service, Texas A&M Sea Grant College ProgramKey words: red tide, dinoflagellate, bloom, toxin, Ptychodiscus brevis, Gonyaulax monilata,Gulf of Mexico, fish kills, neurotoxic shellfish poisoningSummary: This pamphlet summarizes the pertinent facts about the red tide organisms,Ptychodiscus brevis and Gonyaulax monilata [now known as Gymnodinium breveand Alexandrium monilata, resp.]; causes of sudden blooms; locations and timesof bloom occurrence; red tide impacts on marine life, public health and theeconomy; myths about red tides; history and folklore; and control, prevention andprediction.Methods: N/A (Public information bulletin)QA/QC: N/AContact: Rhonda SniderSource Inst.: Marine Information Service, Sea Grant College Program, Texas A&MUniversity, College Station, TX 77843-4115Author: Starr, T. J.Date: 1958Title: Notes on a toxin from Gymnodinium breveJournal: Texas Reports in Biology and Medicine 16:500-507Key words: toxin, Gymnodinium breve, bloom, algae, culture, mullet, Lebistes reticulatus,Mugel cephalus, exotoxin, endotoxinSummary: This paper describes bioassay procedures for toxin from unialgal cultures ofGymnodinium breve as well as some properties of the crude toxin. Mullet andguppies were used for the toxin bioassay; toxicity increases with any agent thatdestroys G. breve. The organism's fragile nature frustrated attempts toconcentrate the toxin by concentrating intact cells. The author cannot concludethat G. breve toxin is either a true exotoxin (produced or excreted from livingcells) or endotoxin (introduced by cell lysis or autolysis).Methods: See "Materials and Methods."QA/QC: None per se; see "Materials and Methods."Contact: Theodore J. StarrSource Inst.: The University of Texas Medical Branch, Department of Preventive Medicine andPublic Health, Virus Research Laboratory, Galveston, Texas, USAAuthor: Stehn, T.Date: 1987Title: Whooping cranes during the 1986-1987 winterPages: 45 pp.Source: Aransas National Wildlife Refuge, U. S. Fish and Wildlife Service149

Key words: whooping crane, habitat, red tide, algae, Ptychodiscus brevis, toxin, clamSummary: In an excerpt from the unpublished report, the author reveals that the Ptychodiscusbrevis [now Gymnodinium breve] red tide of 1986-87 in South Texas came veryclose to infiltrating whooping crane critical habitat in the Aransas National WildlifeRefuge in the fall of 1986. Because clams, swallowed whole, comprise a smallpart of a whooping crane's diet in fall and early winter, brevetoxin could possiblysicken or kill any cranes consuming contaminated clams. Because scaup andcormorants have been known to perish from exposure to brevetoxin in Florida, thepotential threat to the small population of endangered whooping cranes calls forfuture monitoring.Methods: None (unpublished report)QA/QC: N/AContact: Tom Stehn, Refuge BiologistSource Inst.: Aransas National Wildlife Refuge, US Fish and Wildlife Service, P. O. Box100, Austwell, TX 77950 USAAuthor: Steidinger, K. A.Date: 1964Title: Gymnodinium breve DavisSource: Florida Board of Conservation Leaflet Series: Plankton, Vol. 1, No. 1 (2 pp.)Key words: Gymnodinium breve, red tide, cyst, neurotoxin, bloom, dinoflagellate, Gulf ofMexico, salinity, temperatureSummary: This monograph provides a drawing, photomicrographs and a description of thered tide dinoflagellate Gymnodinium breve, plus comments on its distribution andecology.Methods: None (description)QA/QC: N/AContact: Karen A. SteidingerSource Inst.: Florida Department of Natural Resources, Bureau of Marine Research, St.Petersburg, FL 33701 USAAuthor: Steidinger, K. A.Date: 1975aTitle/Chap.: Basic factors influencing red tidesBook: Proceedings of the First International Conference on Toxic DinoflagellateBloomsEditor: V. R. LoCiceroPages: 153-162Publisher: The Massachusetts Science and Technology Foundation, Wakefield, MAKey words: red tide, bloom, bloom initiation, dinoflagellate, sexual phase, benthic cyst, seedpopulation, Gymnodinium breve, FloridaSummary: The author sets forth the three aspects common to all toxic red tides: (1) bloominitiation, defined as an increase in population size; (2) support, in terms offavorable levels of nutrients, growth factors, temperature and salinity; and (3)bloom maintenance and transport by meteorologic and hydrologic forces. At timeof publication, dormant stages in the form of benthic cysts had not been150

substantiated for G. breve (though true for many other species) nor had theconcept of "seed populations" been proven, but such life cycle work was of highpriority. The locality of bloom initiation was also considered critical, an examplebeing the general location of G. breve blooms, at depths of 12-37 m 16-64 kmoffshore of southwest Florida, as a likely place to find dormant cysts. G. breveblooms, at least, were characterized from available data as gradual increases inmotile cells, not sudden increases in cell division rates. Important transporting andconcentrating mechanisms are listed as winds, currents and organism migration.Offshore sampling programs for adequate warning of blooms are highlyrecommended.Methods: None (review)QA/QC: N/AContact: Karen A. SteidingerSource Inst.: Florida Department of Natural Resources, Marine Research Laboratory, 100Eighth Ave. S. E., St. Petersburg, FL 33701 USAAuthor: Steidinger, K. A.Date: 1975bTitle: Implications of dinoflagellate life cycles on initiation of Gymnodinium breve redtidesJournal: Environmental Letters 9(2):129-139Key words: dinoflagellate, life cycle, initiation, Gymnodinium breve, red tide, Florida, restingcyst, hypnozygote, seed population, sexualitySummary: West Florida coastal waters 18-74 km offshore are the sites of red tide bloominitiation, usually in late summer or fall. If G. breve has a sexual cycle involvingalternation of generations that includes a resting cyst stage (hypnozygote), thenseed populations or seed "beds" could be located and mapped. The author reviewsin detail advances in dinoflagellate life cycle work.Methods: None (review)QA/QC: N/AContact: Karen A. SteidingerSource Inst.: Florida Department of Natural Resources, Marine Research Laboratory, 100Eighth Ave. S. E., St. Petersburg, FL 33701 USAAuthor: Steidinger, K. A.Date: 1979Title/Ch.: Collection, enumeration and identification of free-living marine dinoflagellatesBook: Toxic Dinoflagellate Blooms, Proceedings of the Second International Conferenceon Toxic Dinoflagellate Blooms, Key Biscayne, Florida, Oct. 31-Nov. 5, 1978Editor: D. L. Taylor and H. H. SeligerPages: 435-442Publisher: Elsevier/North-Holland, Inc.Key words: dinoflagellate, Peridinales, theca, armored, unarmored, toxin, bloom, PtychodiscusbrevisSummary: Water samples of dinoflagellates can be collected by numerous mechanical meansdepending on the species of interest, the study area and the researcher’s purpose.151

Formalin as both fixative and preservative is suggested for armored specimens, butunarmored species are difficult to fix and preserve. Enumeration methods arevaried for both living and preserved cells. Plates of armored species may bedistinguished optically, with stains, or by physical or chemical separation; cell size,shape, number and organelle placement are among other diagnostic features usedto identify unarmored dinoflagellates. Cultures may confound identification due toculture-specific anomalous effects. Toxic species are thought to number less than20, though many more produce blooms in estuaries and neritic waters. The namePtychodiscus brevis [since renamed as Gymnodinium breve] is proposed for atoxic, bloom-producing species.Methods: N/A (Review paper)QA/QC: N/AContact: Karen A. SteidingerSource Inst.: Florida Department of Natural Resources, Marine Research Laboratory, 100Eighth Ave. S. E., St. Petersburg, FL 33701 USAAuthor: Steidinger, K. A.Date: 1983Title/Ch.: A re-evaluation of toxic dinoflagellate biology and ecologyBook: Progress in Phycological Research, Vol. 2Editor: Round and ChapmanPages: 147-188Publisher: Elsevier Science Publishers B. V.Key words: toxic dinoflagellate, Ptychodiscus brevis, Gymnodinium breve, Gonyaulaxmonilata, Pyrrhophyta, neurotoxin, hemolytic agent, bloom, systematics, lifehistorySummary: This review summarizes toxic dinoflagellate research to 1983, commenting onsystematics, life histories, toxins, organismal activity, environmental impacts andcertain ecological aspects and suggesting avenues for future work. The two redtide dinoflagellates known to afflict the Texas Gulf Coast are included.Methods: N/A (Review paper)QA/QC: N/AContact: Karen A. SteidingerSource Inst.: Florida Department of Natural Resources, Bureau of Marine Research, St.Petersburg, FL 33701 USAAuthor: Steidinger, K. A. and Haddad, K.Date: 1981Title: Biologic and hydrographic aspects of red tidesJournal: Bioscience 31(11):814-819Key words: red tide, bloom, dinoflagellate, life cycle, initiation, endotoxin, Ptychodiscus brevis[now Gymnodinium breve], sexual reproduction, satellite imagerySummary: This article summarizes red tides in general, dinoflagellate biology, the sequentialdevelopment of red tides and their occurrence in Florida, providing an excellentintroduction to the state of knowledge and research on the factors concerning redtides in the eastern Gulf of Mexico as of 1981.152

Methods: None (review)QA/QC: N/AContact: K. A. SteidingerSource Inst.: Bureau of Marine Research, Florida Department of Natural Resources, St.Petersburg, Fl 33701 USAAuthor: Steidinger, K. A. and Ingle, R. M.Date: 1972Title: Observations on the 1971 summer red tide in Tampa Bay, FloridaJournal: Environmental Letters 3(4):271-278Key words: red tide, Tampa Bay, Florida, dinoflagellate, Gymnodinium breve, bloom, cyst,estuaries, reefs, bivalvesSummary: Using information from a summer red tide on the west Florida coast that persistedfor 3.5 months, the authors' observations suggest that (1) Gymnodinium breve is aneritic species hindered by low salinity barriers in estuaries, (2) dense cellconcentrations are due more to physical factors than rapid cell division, (3) G.breve temporarily affects inshore and nearshore reef fisheries only, (4) commercialshellfish may be safely consumed 1-2 months after the end of a red tide event, (5)cyst populations in residence may become G. breve blooms, (6) pollution is not thecatalyst for a Florida red tide, (7) G. breve blooms are probably annualoccurrences and (8) monitoring programs can predict major Florida red tides.Methods: None per se; methodological comments appear in "Results and Discussion."QA/QC: N/A (Descriptive)Contact: Karen A. SteidingerSource Inst.: Florida Department of Natural Resources, Bureau of Marine Research, St.Petersburg, FL 33701 USAAuthor: Steidinger, K. A. and Joyce, E. A., Jr.Date: 1973Title: Educational Series No. 17: Florida Red TidesPages: 26 pp.Publisher: State of Florida Department of Natural Resources, St. PetersburgKey words: Florida, red tide, Gymnodinium breveSummary: Gymnodinium breve, according to the authors, was very likely responsible fornumerous recorded fish kills in Florida as early as 1844, but was not recognizedand identified as the causative agent until 1948. Stating that red tides are naturaloccurrences, the authors conclude that there is a lack of means to control red tideswith a concomitant warning that such means might harm the environment even ifavailable.Methods: N/A (Review paper)QA/QC: N/AContact: Karen A. SteidingerSource Inst.: Florida Department of Natural Resources, Bureau of Marine Research, St.Petersburg, FL 33701 USAAuthor: Steidinger, K. A. and Vargo, G. A.153

Date: 1988Title/Ch.: 15. Marine dinoflagellate blooms: dynamics and impactsBook: Algae and Human AffairsEditor: C. A. Lembi and J. R. WaalandPages: 373-401Publisher: Cambridge University Press, New York, NYKey words: dinoflagellate, bloom, microalgae, Pyrrhophyta, red tide, paralytic shellfishpoisoning, neurotoxic shellfish poisoning, diarrhetic shellfish poisoning,phytoplanktonSummary: A general review of the mechanisms and effects of marine dinoflagellate blooms,this paper recommends a multidisciplinary approach to identifying the physicalchemicalforces of and biological responses to blooms. Hydrographic effects alterdinoflagellate behavior and location; variable light conditions can beaccommodated by the organism’s ability to modify photosynthetic pigment qualityand quantity. Dinoflagellates can migrate and store nutrients; certain speciesproduce toxins, and some bioluminesce. Reports of toxic blooms (red tides) areon the increase, including occurrences in areas previously unaffected; such bloomscan restructure marine communities via selective mortality, threatening publichealth, commercial fishing and shellfish industries. Outside of negative economicimpacts and health concerns, red tides, being natural occurrences, may notnecessarily cause long-term negative ecological impacts.Methods: N/A (Review paper)QA/QC: N/AContact: Karen A. SteidingerSource Inst.: Florida Department of Natural Resources, Bureau of Marine Research, St.Petersburg, FL 33701 USAAuthor: Steidinger, K. A., and Williams, J.Date: 1964Title: Gymnodinium breve DavisSource: Florida Board of Conservation Leaflet Series: Plankton, Vol. 1, No. 1A(Supplement, 2 pp.)Key words: Gymnodinium breve, dinoflagellate, red tide, fish mortality, cyst formation,encystment, chromatophores, nucleus, FloridaSummary: The principal author published a monograph in the same leaflet series in early 1964to which this is a supplement providing drawings, photomicrographs anddocumented observations of the red tide dinoflagellate Gymnodinium breve. The63 cells collected and observed from a Florida outbreak causing fish mortality inmid-1964 differed from previous published observations, especially with respect tonucleus position, ventral concavity/dorsal convexity, the overhanging apicalprocess and the length/breadth of the body. Also described was the process ofencystment.Methods: None (description)QA/QC: N/AContact: Karen A. Steidinger154

Source Inst.: Florida Department of Natural Resources, Bureau of Marine Research, St.Petersburg, FL 33701 USAAuthor: Steidinger, K., Babcock, C., Mahmoudi, B., Tomas, C. and Truby, E.Date: 1989Title/Ch.: Conservative taxonomic characters in toxic dinoflagellate species identificationBook: Red tides: biology, environmental science, and toxicology. Proceedings of theFirst International Symposium on Red Tides held November 10-14, 1987, inTakamatsu, Kagawa Prefecture, Japan.Editor: T. Okaichi, D. M. Anderson and T. NemotoPages: 285-288Publisher: Elsevier Science Publishing Company, Inc., New YorkKey words: numerical taxonomy, toxic, dinoflagellate, species identification, Gymnodinium,Gyrodinium, Ptychodiscus, Prorocentrum, optical pattern recognitionSummary: Proper identification is of concern to areas experiencing dinoflagellate blooms,especially those with no historical record of nor data on life history, biochemistryor growth of the bloom species. All such information is necessary for scientists toestimate negative impacts and establish monitoring programs. The taxonomy oftoxic dinoflagellates is unfortunately still at the morphospecies level, andidentification of conservative morphological characters/descriptors is still essential.This paper offers some apparently uniform, objective criteria to identify toxicdinoflagellate species.Methods: See "Experimental."QA/QC: None per se; see "Experimental."Contact: Karen SteidingerSource Inst.: Bureau of Marine Research, Florida Department of Natural Resources, St.Petersburg, Fl 33701 USAAuthor: Stockwell, D. A., Buskey, E. J. and Whitledge, T. E.Date: 1993Title/Ch.: Studies on conditions conducive to the development and maintenance of apersistent “brown tide” in Laguna Madre, TexasBook: Toxic Phytoplankton Blooms in the SeaEditor: T. J. Smayda and Y. ShimizuPages: 693-698Publisher: Elsevier Science Publishers B. V.Key words: brown tide, Laguna Madre, Texas, Baffin Bay, bloom, chrysophyte, Aureococcusanophagefferens, Pelagoccus subviridis, dimethyl sulfide, microzooplanktonSummary: A 4-5 µm diameter organism similar to the Type III, aberrant group ofchrysophytes appeared as a bloom from 6/90 and persisted for more than 18months thereafter in the hypersaline waters of Baffin Bay and the Upper LagunaMadre of South Texas. Cell densities reached the order of 10 9 cells/l withchlorophyll a concentrations as much as 70 µg/l. The organism is capable ofproducing large amounts of dimethyl sulfide (DMS) and, while at maximum bloomin 7/90, was linked to a great reduction in microzooplankton grazing rates. The155

authors suggest the coincidence of regional drought, local hypersalinity and theuncoupling of water column processes from the benthos led to the bloom.Methods: See “Methods.”QA/QC: None per se; see “Methods.”Contact: Dean A. StockwellSource Inst.: Marine Science Institute, The University of Texas at Austin, P. O. Box 1267, PortAransas, TX 78373-1267 USAAuthor: Taylor, F. J. R.Date: 1990Title/Ch.: Red tides, brown tides and other harmful algal blooms: the view into the 1990’sBook: Toxic Marine Phytoplankton, Proceedings of the Fourth International Conferenceon Toxic Marine PhytoplanktonEditor: E. Granéli, B. Sundström, L. Edler and D. M. AndersonPages: 527-533Publisher: ElsevierKey words:Summary:red tide, brown tide, algae, bloom, phytoplankton,A concise overview of the proceedings of the Fourth International Conference onToxic Marine Phytoplankton, this summary paper identifies what the authorconsidered the major outstanding problems remaining (ca. 1990) in the study oftoxic marine phytoplankton. Foremost for the purpose of this annotation are theelusive goal of accurate bloom prediction in most regions, the apparent increase infrequency of harmful blooms and the possibility of artificial dispersal (e.g., in theballast water of ships) of bloom species from formerly restricted ranges ofoccurrence to distant sites.Methods: N/AQA/QC: N/AContact: F. J. R. TaylorSource Inst.: Departments of Oceanography and Botany, Univeristy of British Columbia,Vancouver, B. C., Canada V6T 1W5Author: Tester, P. A.Date: 1992Title/Chap.: Section VI: Phytoplankton distributionReport: Report on Investigation of 1990 Gulf of Mexico Bottlenose Dolphin StrandingsEditor: L. J. HansenPages: 44-47; Table 1; Figures 1-4; Appendix VPublisher: National Oceanic and Atmospheric Administration, National Marine FisheriesServiceKey words: phytoplankton, Gymnodinium breve, dinoflagellate, Gulf of Mexico, red tide,bloom, brevetoxin, marine mammals, Galveston Bay, Mississippi deltaSummary: Of the 123 phytoplankton samples collected in the primary study area (betweenGalveston Bay and the Mississippi delta) in March of 1990, 80% contained G.breve cells. Upon detailed examination of the 70 samples taken in the upper halfof the water column, 94% revealed the presence of G. breve cells, and 65%contained more than 50 cells/liter. Bloom concentrations are considered as at least156

5000 cells/liter, so the cell counts from this study can be categorized as "normalbackground levels," but they were consistently greater than counts of samples fromsimilar areas or from the primary study area later in the summer of 1990. (At thattime, another toxic dinoflagellate, Gonyaulax [now Alexandrium] monilata wasfound near the Mississippi delta in elevated concentrations.)Methods: See "Methods."QA/QC: None per se; see "Methods."Contact: Patricia A. TesterSource Inst.: Southeast Fisheries Science Center (NOAA/NMFS), Beaufort Laboratory,Beaufort, NC 28516Author: Tester, P. A. and Fowler, P. K.Date: 1990Title/Ch.: Brevetoxin contamination of Mercenaria mercenaria and Crassostrea virginica: amanagement issueBook: Toxic Marine Phytoplankton, Proceedings of the Fourth International Conferenceon Toxic Marine PhytoplanktonEditor: E. Granéli, B. Sundström, L. Edler and D. M. AndersonPages: 499-503Publisher: ElsevierKey words: brevetoxin, Mercenaria mercenaria, Crassostrea virginica, red tide, Ptychodiscusbrevis, bloom, North Carolina, shellfish, clamSummary: The authors examine factors affecting the toxicity of Mercenaria mercenaria andCrassostrea virginica during and after a P. brevis [aka Gymnodinium breve]bloom in the field and suggest changes in the American Public Health Associationguidelines concerning what is an acceptable amount of neurotoxic shellfishpoisoning (NSP) toxin in shellfish harvested for human consumption. They alsonote that P. brevis requires salinities in excess of 24 ppt.Methods: See “Methods.”QA/QC: None per se; see “Methods.”Contact: Patricia A. TesterSource Inst.: National Marine Fisheries Service, NOAA, Beaufort, NC 28516 USAAuthor: Tester, P. A., Geesey, M. A. and Vukovich, F. M.Date: 1993Title/Ch.: Gymnodinium breve and global warming: what are the possibilities?Book: Toxic Phytoplankton Blooms in the Sea, Proceedings of the Fifth InternationalConference on Toxic Marine PhytoplanktonEditor: T. J. Smayda and Y. ShimizuPages: 67-72Publisher: Elsevier Science Publishers B. V.Key words: Gymnodinium breve, global warming, Gulf Stream, North Carolina, red tide,bloom, South Atlantic Bight, Florida Current, Gulf of MexicoSummary: An unusual red tide bloom in North Carolina in 1987-88 may have resulted fromtransport of a seed population from the west Florida shelf into the South AtlanticBight (SAB) by the Florida Current-Gulf Stream System. Continuous transport of157

this kind has been implicated by water samples collected by NOAA vessels in thenorthern Gulf of Mexico (GOM) and the SAB, for G. breve appears to becontinously distributed from the GOM throughout the SAB regardless of season.Twelve incursions of the warmer Gulf Stream into the shelf waters of the SABwere associated with detectable levels of G. breve cells during the winter of 1990-91. When SAB shelf water temperatures increase in summer, Gulf Streamincursions are more difficult to detect and the growth of G. breve populations isbetter supported. Variations in the transport and distribution of G. breve may beuseful for assessing global climate change and its effects on the water temperatureand circulation patterns between the GOM and the SAB. The authors add that oneliter was the minimum volume necessary for detection of G. breve cells in theSAB, at least ten times the quantity typically examined with the standard Utermöhlsettling chamber methodology.Methods: See "Introduction."QA/QC: None per se; see "Introduction."Contact: Patricia A. TesterSource Inst.: National Marine Fisheries Service--NOAA, Southeast Fisheries Science Center,Beaufort Laboratory, Beaufort, NC 28516 USAAuthor: Tester, P. A., Stumpf, R. P., Vukovich, F. M., Fowler, P. K., and Turner, J. T.Date: 1991Title: An expatriate red tide bloom: transport, distribution, and persistenceJournal: Limnol. Oceanogr. 36(5):1053-1061Key words: red tide, bloom, transport, distribution, dinoflagellate, Gymnodinium breve, NorthCarolina, Gulf of Mexico Loop Current, Florida Current, Gulf StreamSummary: A Gymnodinium breve bloom occurred in North Carolina nearshore waters inNovember of 1987, the first to occur north of Florida due to G. breve. Theauthors propose that the Gulf Stream Loop Current entrained a portion of a G.breve bloom in progress off the southwest Florida coast, then transported it, viathe Florida Current-Gulf Stream system, around the Florida peninsula and northover 800 km and 22-54 days to North Carolina. Thirty days after the southwestFlorida bloom, satellite sea-surface temperature images confirmed movement of aparcel of Gulf Stream water onto the shelf between Cape Hatteras and CapeLookout and its residence there for >19 days, a likely source of the G. breve cells.Once inshore, windspeed and direction largely controlled its distribution.Methods: None per se (note).QA/QC: N/AContact: Patricia A. TesterSource Inst.: National Marine Fisheries Service, NOAA, Southeast Fisheries Center, BeaufortLaboratory, Beaufort, NC 28516 USAAuthor: Texas Parks and Wildlife DepartmentDate: 1986Title: Commission Agenda Item (Briefing Session): Red TidePages: 3 pp.158

Key words: red tide, bloom, algae, dinoflagellate, Ptychodiscus brevis, neurotoxin, Gulf ofMexico, aerial surveillance, fish mortality, aerosol toxinSummary: This report highlights the impact on marine fishes by the red tide dinoflagellatePtychodiscus brevis during the extensive bloom that began during Labor Dayweekend of 1986. The red tide moved steadily southward from the first fish killnoted offshore of Galveston, Texas, and by November had reached Mexicanbeaches at Tampico and the Bay of Campeche. Causative factors were unclear, forthe organism's preference for salinities greater than 28 ppt and temperaturesexceeding 60 o F is commonly fulfilled in late summer along Texas shores, yetwithout blooms. Total fish mortality was estimated at more than 7.5 millionindividuals, mainly menhaden and mullet, but including pinfish, red drum, spottedseatrout, black drum, southern flounder and Atlantic croaker. Oyster harvestingwas prohibited, and numerous beaches were closed due to dead fish and aerosoltoxin.Methods: N/A (Briefing report)QA/QC: N/AContact: Larry McEachronSource Inst.: Texas Parks & Wildlife Department, Coastal Fisheries Division, 702 NavigationCircle, Rockport, TX 78382Author: Tracey, G. A.Date: 1988Title: Feeding reduction, reproductive failure, and mortality in Mytilus edulis during the1985 ‘brown tide’ in Narragansett Bay, Rhode IslandJournal: Mar. Ecol. Prog. Ser. 50:73-81Key words: feeding, reproduction, mortality, Mytilus edulis, brown tide, Narragansett Bay,Rhode Island, bloom, chrysophyte, Mercenaria mercenaria,Summary: The blue mussel, Mytilus edulis, suffered reduced clearance rates, reproductivefailure and high mortality in response to a dense, novel brown tide bloom (10 6cells/ml) in Narragansett Bay, RI in the summer of 1985. Using naturalparticulates from Narragansett Bay in the clearance rate experiments with the bluemussel, the authors replicated the experiment and saw similar inhibition in the hardclam, Mercenaria mercenaria. Deleterious experimental effects appeared whenparticles exceeded 5.0 x 10 5 particles/ml, whereas bay concentrations ranged from9 x 10 5 to 15 x 10 5 particles/ml. Blue mussel mortality in the bay varied from 30-100% with concomitant reproductive failure, neither of which could be attributedto temperature, salinity or dissolved oxygen concentrations.Methods: See “Materials and Methods.”QA/QC: None per se; see “Materials and Methods.”Contact: Gregory A. TraceySource Inst.: Science Applications International Corporation, Marine Services Branch, USEnvironmental Protection Agency, Environmental Research Laboratory,Narragansett, Rhode Island 92882 USAAuthor: Tracey, G. A., Johnson, P. W., Steele, R. W., Hargraves, P. E. and Sieburth, J.McN.159

Date: 1988Title: A shift in photosynthetic picoplankton composition and its effect on bivalvemollusc nutrition: the 1985 “brown tide” in Narragansett Bay, Rhode IslandJournal: Journal of Shellfish Research 7(4):671-675Key words: photosynthesis, picoplankton, bivalve, mollusc, nutrition, brown tide, NarragansettBay, Synechococcus, bloom, Mytilus edulisSummary: Upon analysis by epifluorescence and transmission electron microscopy, watersamples from the brown tide bloom of 1985 in Narragansett Bay, Rhode Island,revealed 10-fold greater concentrations of bacteria (10 7 cells/ml) during the peakof the bloom. A 1.5-2.0 µm chrysophyte composed 95% of the totalphytoplankton by abundance at about 10 6 cells/ml. The photosyntheticcyanobacterium Synechococcus was 10-fold lower in abundance than the usual 5 x105 cells/ml. The brown tide organism reduced feeding in the mussel Mytilusedulis, but clearance rates were optimal for comparable densities of a similar-sizedstrain of Synechococcus. The mussel’s nutrition and growth may thus be affectedby the species composition of the picoplankton.Methods: See “Materials and Methods.”QA/QC: None per se; see “Materials and Methods.”Contact: Gregory A. TraceySource Inst.: Science Applications International Corporation, Marine Services Branch, c/o U. S.Environmental Protection Agency, South Ferry Rd., Narragansett, RI 02882USAAuthor: Tracey, G. A., Steele, R. L., Gatzke, J., Phelps, D. K., Nuzzi, R., Waters, M. andAnderson, D. M.Date: 1989Title/Ch.: Testing and application of biomonitoring methods for assessing environmentaleffects of noxious algal bloomsBook: Novel Phytoplankton Blooms: Causes and Impacts of Recurrent Brown Tides andOther Unusual Blooms, Coastal and Estuarine Studies 35Editor: E. M. Cosper, V. M. Bricelj and E. J. CarpenterPages: 557-574Publisher: Springer-VerlagKey words: biomonitoring, bloom, Aureococcus anophagefferens, Peconic Bay, Long Island,New York, brown tide, mussel, Mytilus edulus, Minutocellus polymorphusSummary: The authors evaluated biomonitoring methods in waters with a history of noxiousalgal blooms, in this case the Peconic Bays system of Long Island, New York,where a mild bloom occurred in June-September, 1988. Objectives included (1)the effect on bivalve nutrition by the characteristics of algae and other suspendedparticulates and (2) the effect on bivalve growth and physiology by environmentalconditions in different bay locations. Reduced feeding and slower growth formussels in Peconic Bay were attributed in the main to the deleterious influence ofAureococcus anophagefferens, with possible added negative effects due to thenanoplanktonic diatom, Minutocellus polymorphus.Methods: See “Methods.”QA/QC: None per se; see “Methods.”160

Contact: Gregory A. TraceySource Inst.: Science Applications International Corporation, c/o U. S. EnvironmentalProtection Agency, Environmental Research Laboratory-Narragansett,Narragansett, Rhode Island 02882 USAAuthor: Tracey, G., Steele, R. and Wright, L.Date: 1990Title/Ch.: Variable toxicity of the brown tide organism, Aureococcus anophagefferens, inrelation to environmental conditions for growthBook: Toxic Marine Phytoplankton, Proceedings of the Fourth International Conferenceon Toxic Marine PhytoplanktonEditor: E. Granéli, B. Sundström, L. Edler and D. M. AndersonPages: 128-131Publisher: ElsevierKey words: toxicity, brown tide, Aureococcus anophagefferens, growth, blue mussel, MytilusedulisSummary: Varying light, temperature and nutrient regimes in A. anophagefferens cultures,then checking the feeding response of M. edulis on the brown tide organism, theauthors found that Aureococcus toxicity in late-exponential phase growth waslower in low light as opposed to high light, greater at higher versus lowertemperatures and increased in high rather than low nutrient concentrations. Thesame kinds of conditions may affect the alga’s toxicity in situ.Methods: See “Materials and Methods.”QA/QC: None per se; see “Materials and Methods.”Contact: Gregory TraceySource Inst.: Science Applications International Corporation, c/o U. S. EnvironmentalProtection Agency, Narragansett Bay, Rhode Island 02882 USAAuthor: Trainer, V. L. and Baden, D. G.Date: 1990Title/Ch.: Enzyme immunoassay of brevetoxinsBook: Toxic Marine Phytoplankton, Proceedings of the Fourth International Conferenceon Toxic Marine PhytoplanktonEditor: E. Granéli, B. Sundström, L. Edler and D. M. AndersonPages: 430-435Publisher: ElsevierKey words: enzyme, immunoassay, brevetoxin, Ptychodiscus brevis (aka Gymnodinium breve),red tide, dinoflagellate, ELISA, enzyme-linked immunosorbent assay, FloridaSummary: At the time of the study, the only assays available to detect the presence ofbrevetoxins in seafood were impractical for field use. The authors analyzed theusefulness of two different brevetoxin-enzyme conjugates via enzyme-linkedimmunosorbent assays (ELISAs), the results of which are visual and could possiblybe read in the field. The two toxin-enzyme conjugates can be standardized to testfor brevetoxin in unknown field samples, though their stability must first beassessed and the overall anti-brevetoxin ELISA optimized.Methods: See “Methods.”161

QA/QC: None per se; see “Methods.”Contact: Vera L. TrainerSource Inst.: Department of Biochemistry and Molecular Biology, University of Miami, Miami,FL 33149 USAAuthor: Trebatoski, B.Date: 1988Title: Observations on the 1986-1987 Texas Red Tide (Ptychodiscus brevis), Report 88-02Pages: 48 pp.Publisher: Texas Water CommissionKey words:Summary:red tide, Ptychodiscus brevis, Texas, dinoflagellate, Gulf of MexicoThis study documents the spread and impact of a bloom of the toxic dinoflagellatePtychodiscus brevis [now Gymnodinium breve] that affected Gulf of Mexicocoastal waters from Galveston to Port Isabel, Texas, and on into Mexico fromAugust 1986 through January 1987. Plankton and water chemistry samples alongwith boat and aerial surveys were the prinicipal means of judging the effects of thered tide, which produced massive fish mortality, irritating aerosols andcontamination of shellfish beds and discouraged tourism and seafood consumption.The resulting large-scale bioperturbation actually may have been a positiveinfluence on the environment.Methods: See “Methods.”QA/QC: None per se; see “Methods.”Contact: Bob TrebatoskiSource Inst.: Texas Water Commission, P. O. Box 13087, Austin, TX 78711 USAAuthor: Vargo, G. A., Carder, K. L., Gregg, W., Shanley, E., Neil, C., Steidinger, K. A.and Haddad, K. D.Date: 1987Title: The potential contribution of primary production by red tides to the west Floridashelf ecosystemJournal: Limnol. Oceanogr. 32(3):762-767Key words: primary production, red tide, west Florida shelf, dinoflagellate, bloom,Ptychodiscus brevis, CZCS imagerySummary: Field and laboratory estimations of and some data for daily and monthlyproduction rates and theoretical annual carbon input for the red tide dinoflagellatePtychodiscus brevis [now Gymnodinium breve] revealed that bloom rates were 2-5 times greater than published values or non-bloom rates. Annually, red tideblooms of P. brevis could be responsible for a significant proportion of annualproduction in the water column of the west Florida shelf.Methods: None per se; see text. (Research note)QA/QC: N/AContact: Gabriel A. VargoSource Inst.: Department of Marine Science, University of South Florida, 140 7th Ave. South,St. Petersburg, FL 33701 USA162

Author: Vargo, G. A. and Howard-Shamblott, D.Date: 1990Title/Ch.: Phosphorus dynamics in Ptychodiscus brevis: cell phosphorus, uptake and growthrequirementsBook: Toxic Marine Phytoplankton, Proceedings of the Fourth International Conferenceon Toxic Marine PhytoplanktonEditor: E. Granéli, B. Sundström, L. Edler and D. M. AndersonPages: 324-329Publisher: ElsevierKey words: phosphorus, Ptychodiscus brevis, bloom, West Florida Shelf, red tide,dinoflagellate, Gulf of MexicoSummary: This study concerns nutrient-growth interactions for P. brevis (renamedGymnodinium breve) and phosphorus. Blooms of this species are initiated 18 to74 km offshore of Florida’s west coast in highly oligotrophic waters. Bloompersistence should be related to the ability to efficiently extract, stock and usenutrients for growth and maintenance, but P. brevis does not possess a highphosphorus storage capacity, though it can apparently store phosphorus in twodifferent cellular storage pools, the significance to growth of which has yet to bedetermined. Phosphorus uptake rates for P. brevis, however, are more than anorder of magnitude above those of other dinoflagellates. The uptake rates, halfsaturationconstant for growth and long generation times of P. brevis enable it tobloom in the presence of relatively excess phosphorus and maintain populations inoffshore waters with low phosphorus concentrations.Methods: See “Methods.”QA/QC: None per se; see “Methods.”Contact: Gabriel A. VargoSource Inst.: Department of Marine Science, University of South Florida, 140 Seventh AvenueSouth, St. Petersburg, Florida 33701 USAAuthor: Vieira, M. E. C. and Chant, R.Date: 1993Title: On the contribution of subtidal volume fluxes to algal blooms in Long IslandestuariesJournal: Estuarine, Coastal and Shelf Science 36:15-29Key words: algae, bloom, Long Island, estuary, subtidal volume flux, picoplankton,Aureococcus anophagefferens, sea level fluctuation, flushing time, wind stressSummary: Tidal data taken from 1980-88 for oceanic locations near Nantucket, MA,Montauk, NY and Atlantic City, NJ and for four Long Island estuaries revealedthat sea level fluctuations due to subtidal frequencies were greater than tidalfrequencies and were seasonal in their magnitude. When the spring1985 browntide bloom (Aureococcus anophagefferens) occurred along with a drought in LongIsland bays, subtidal variance was at an absolute minimum, subtidal flushing timeswere correspondingly slow and freshwater influx was reduced. As a result,inorganic nutrients may have been available for longer than usual, supporting theexpansive bloom of A. anophagefferens.Methods: See “Data Base.”163

QA/QC: None per se; see “Data Base” and “Analysis and Results.”Contact: Mario E. C. VieiraáSource Inst.: Oceanography Department, US Naval Academy, Annapolis, MD 21402-5026USAAuthor: Walker, L. M.Date: 1982Title: Evidence for a sexual cycle in the Florida red tide dinoflagellate, Ptychodiscusbrevis (= Gymnodinium breve)Journal: Transactions of the American Microscopical Society 101(3):287-293Key words: sexual cycle, Florida, red tide, dinoflagellate, Gymnodinium breve, gametes,planozygotes, cystSummary: Non-clonal stock cultures provided evidence of isogamous, haploid gametes anddiploid planozygotes in the sexual cycle of Gymnodinium breve. Though nohypnozygotes were ever positively identified in the cultures, apparenthypnozygotic cysts may have formed in one preliminary experiment and were alsorecovered from field samples.Methods: See "Materials and Methods."QA/QC: None per se; see "Materials and Methods."Contact: Linda M. WalkerSource Inst.: Florida Department of Natural Resources, Marine Research Laboratory, 100Eighth Avenue South East, St. Petersburg, Florida 33701-5095 USAAuthor: Walker, L. M., and Steidinger, K. A.Date: 1979Title: Sexual reproduction in the toxic dinoflagellate Gonyaulax monilataJournal: Journal of Phycology 15:312-315Key words: reproduction, dinoflagellate, Gonyaulax monilata, sexual cycle, isogametes,planozygote, hypnozygote, archeopyle, red tide, seed bedSummary: The authors observed the induction of the sexual cycle of Gonyaulax [nowAlexandrium] monilata in nonclonal laboratory cultures within one week afterinoculating asexual cells into nitrogen-deficient media. Asexual cells can producetwo armored, motile, isogamous gametes. Two gametes fuse to form a largedouble-flagellated planozygote that encysts as a hypnozygote with a three-layeredcyst wall 1-3 weeks later. The cell that emerges from the cyst divides twice toform a four-celled chain within three days. The authors report that cysts of G.monilata were found in Tampa Bay sediments, were excysted and produced chainsof cells identical to those studied in the nonclonal laboratory cultures.Methods: See "Materials and Methods."QA/QC: None per se; see "Materials and Methods."Contact: Linda M. WalkerSource Inst.: Florida Department of Natural Resources, Marine Research Laboratory, 100Eighth Avenue S.E., St. Petersburg, FL 33701Author: Wall, D.Date: 1975164

Title/Chap.: Taxonomy and cysts of red-tide dinoflagellatesBook: Proceedings of The First International Conference on Toxic DinoflagellateBloomsEditor: V. R. LoCiceroPages: 249-255Publisher: The Massachusetts Science and Technology Foundation, Wakefield, MAKey words: taxonomy, cyst, red tide, dinoflagellate, life cycle, theca, Gonyaulax, speciescomplexSummary: Many dinoflagellate species, both estuarine and neritic, produce a cyst at some partof their life cycle. Cysts are composed of a variety of materials, can providetaxonomic information and have indicated that the Genus Gonyaulax is geneticallyheterogeneous with seven species complexes. The G. tamarensis complexincludes red-tide species such as Gonyaulax [now Alexandrium] monilata andpossesses a distinctive thecal morphotype common to all species in the complexand some others. Taxonomic revision is needed for the Genus Gonyaulax andothers, and cyst cycles should be employed to identify species complexes.Methods: None (review)QA/QC: N/AContact: David WallSource Inst.: Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USAAuthor: Ward, J. E. and Targett, N. M.Date: 1989Title/Ch.: Are metabolites from the brown tide alga, Aureococcus anophagefferens,deleterious to mussel feeding behavior?Book: Novel Phytoplankton Blooms: Causes and Impacts of Recurrent Brown Tides andOther Unusual Blooms, Coastal and Estuarine Studies 35Editor: E. M. Cosper, V. M. Bricelj and E. J. CarpenterPages: 543-556Publisher: Springer-VerlagKey words: metabolites, brown tide, Aureococcus anophagefferens, mussel, bloom, Isochrysisgalbana, Heterosigma akashiwo, Dunaliella tertiolectaSummary: Given the adverse effects of A. anophagefferens on bivalves, the lack ofphytoplankton diversity during the brown tide blooms and the high densities of thebrown tide alga, the authors hypothesized a metabolite detrimental to bivalvefeeding behavior. They found, however, no evidence of a negative effect by A.anophagefferens on mussel filtration rates, particle selection or valve movements,even at densities of 10 5 -10 6 cells/ml. Their findings do not rule out toxic effects ofmetabolite exposure for days or weeks, rapidly degrading metabolites or harmfulepicellular constituents.Methods: See “Methods.”QA/QC: None per se; see “Methods.”Contact: J. Evan WardSource Inst.: University of Delaware, College of Marine Studies, Lewes, DE 19958 USAAuthor: Wardle, W. J., Ray, S. M. and Aldrich, A. S.165

Date: 1975Title/Ch.: Mortality of marine organisms associated with offshore summer blooms of thetoxic dinoflagellate Gonyaulax monilata Howell at Galveston, TexasBook: Proceedings of the First International Conference on Toxic DinoflagellateBloomsEditor: V. R. LoCiceroPages: 257-263Publisher: The Massachusetts Science and Technology Foundation, Wakefield, MAKey words: mortality, bloom, dinoflagellate, Gonyaulax monilata, Galveston, Texas, snail,hermit crab, brittle star, red tideSummary: The authors document two red tides of the toxic dinoflagellate Gonyaulaxmonilata [preferred name Alexandrium monilata] that occurred in waters nearGalveston, Texas in the summers of 1971 and 1972, with recorded maximum celldensities of 1.2 x 10 6 cells/L and 1.88 x 10 6 cells/L, respectively. Twenty-ninespecies of cnidarians, annelids, molluscs, crustaceans, echinoderms and fishes, allsedentary or slow-moving, were represented among the organisms that perishedfrom the toxin. Monitoring in the summers of 1973 and 1974 did not detect thepresence of G. monilata, perhaps due to lower salinities (

Date: 1993Title/Ch.: The nutrient and hydrographic conditions prevailing in Laguna Madre, Texasbefore and during a brown tide bloomBook: Toxic Phytoplankton Blooms in the SeaEditor: T. J. Smayda and Y. ShimizuPages: 711-716Publisher: Elsevier Science Publishers B. V.Key words: nutrients, Laguna Madre, Texas, brown tide, bloom, pigment, chrysophyte, BaffinBay, dissolved inorganic nitrogen, ammoniumSummary: An unidentified aberrant chrysophyte bloomed widely for more than 18 months inthe hypersaline Laguna Madre. The bloom followed dissolved inorganic nitrogen(DIN) concentrations of almost 20 µmol/l, especially in Baffin Bay, withammonium composing 60-95% of the DIN. Baffin Bay, subject to annual salinityvariations of as much as 65 ppt, also had the greatest salinity of the north to southgradient in the Laguna Madre, ranging from 40-60 ppt during the bloom.Methods: See “Methods.”QA/QC: None per se; see “Methods.”Contact: Terry E. WhitledgeSource Inst.: Marine Science Institute, The Univerity of Texas at Austin, P. O. Box 1267, PortAransas, TX 78373 USAAuthor: Whitledge, T. E. and Pulich, W. M., Jr.Date: 1991Title: Report of Brown Tide Symposium and Workshop, 15-16 July 1991Pages: 44 pp.Publisher: University of Texas Marine Science Institute Technical Report TR/91-002Key words: brown tide, bloom, seagrass, grazing, nutrients, hydrography, light, benthos,zooplankton, ichthyoplanktonSummary: This report consolidates the abstracts of all presentations given at thesymposium/workshop and summarizes the results in the forms of (1)comparisons/contrasts between characteristics of geographically isolatedoccurrences of brown tide and (2) recommendations for future research.Methods: N/AQA/QC: N/AContact: Terry E. WhitledgeSource Inst.: Marine Science Institute, The University of Texas, P. O. Box 1267, PortAransas, TX 78373 USAAuthor: Williams, J., and Ingle, R. M.Date: 1972Title: Ecological Notes on Gonyaulax monilata (Dinophyceae) Blooms Along the WestCoast of FloridaSource: Florida Department of Natural Resources Leaflet Series: Phytoplankton, Part 1(Dinoflagellates), No. 5Key words: Gonyaulax monilata, dinoflagellate, Florida, fish kill, bloom, Gymnodinium breve167

Summary: The first bloom of the toxic dinoflagellate Gonyaulax monilata [now Alexandriummonilata] off the west coast of Florida is the subject of this note. The organismcaused fish kills and, also for the first time anywhere, was detected blooming inoffshore waters, not just estuarine or nearshore environments, in the late summerof 1966. A Gymnodinium breve bloom followed the G. monilata bloom inOctober.Methods: NoneQA/QC: N/A (Report)Contact: Jean WilliamsSource Inst.: Florida Department of Natural Resources, Bureau of Marine Research, St.Petersburg, FL 33701 USAAuthor: Wilson, W. B.Date: 1965Title: The suitability of sea-water for the survival and growth of Gymnodinium breveDavis; and some effects of phosphorus and nitrogen on its growthJournal: Florida Board of Conservation Professional Papers Series No. 7:1-42Key words: Gymnodinium breve, dinoflagellate, bloom, toxin, growth, phosphorus, nitrogen,chelator, iron, glycerophosphateSummary: The toxic marine dinoflagellate G. breve was used as a bioassay organism to testthe suitability of various seawater samples from the West Florida coast andGalveston Island to support its survival and growth. Of the few seawater samplesthat were suitable, experiments determined which substances used for G. breveculture media would promote growth in those samples. Survival and growth inmost samples were improved by addition of the chelator EDTA or a combinationof EDTA and iron. EDTA, iron and an inorganic mixture with nitrogen andphosphorus improved growth more than any other additive combination in 1964seawater samples, but inorganic nutrients alone were not generally effective. HighG. breve concentrations, however, were not seen in response to most additives.Higher phosphorus concentrations in artificial media supported relatively greatercell densities, but populations with less than 6.0 µg P/liter did not continue togrow. Glycerophosphate as the sole phosphorus source was acceptable; nitratenitritewas not required, but some form of organic nitrogen was essential.Methods: See "Sample Procedure and Assay Methods."QA/QC: None per se; see "Sample Procedure and Assay Methods."Contact: William B. WilsonSource Inst.: Texas A & M Marine Laboratory, Galveston, Texas, USAAuthor: Wilson, W. B.Date: 1967Title: Forms of the dinoflagellate Gymnodinium breve Davis in culturesJournal: Contributions in Marine Science 12:120-134Key words: dinoflagellate, Gymnodinium breve, culture, morphology, encystment stage, cyst,cell division, reproduction, bloom, Gulf of MexicoSummary: Cultured cells of the marine dinoflagellate Gymnodinium breve are described anddiscussed with respect to the most common encystment stage, general features of168

cell division, other possible reproductive stages and forms resulting from variedphysical factors and reproductive stages. The author includes numerousphotographs and some line drawings.Methods: None per se (descriptive paper).QA/QC: N/AContact: William B. WilsonSource Inst.: Marine Laboratory, Texas A & M University, Galveston, Texas, USAAuthor: Wilson, W. B. and Ray, S. M.Date: 1956Title: The occurrence of Gymnodinium brevis in the western Gulf of MexicoJournal: Ecology 87(2):388Key words: Gymnodinium brevis, Gulf of Mexico, fish mortality, Port Isabel, Texas, RioGrande RiverSummary: September of 1955 saw a widely documented fish kill apparently due to the redtide dinoflagellate Gymnodinium brevis [now preferably known as Gymnodiniumbreve] that littered the Gulf coast from a point 17 miles north of Port Isabel to themouth of the Rio Grande in Texas as well as a 120-mile stretch in the Mexicanstate of Tamaulipas. Highest reported densities were found 36 miles south of theRio Grande River mouth at no less than 22,000 cells/ml.Methods: N/A (Report)QA/QC: N/AContact: W. B. WilsonSource Inst.: Gulf Fishery Investigations, U. S. Fish and Wildlife Service, Galveston, TX, USAAuthor: Wilson, W. B., Ray, S. M., and Aldrich, D. V.Date: 1975Title/Chap.: Gymnodinium breve: population growth and development of toxicity in culturesBook: Proceedings of the First International Conference on Toxic DinoflagellateBloomsEditor: V. R. LoCiceroPages: 127-141Publisher: The Massachusetts Science and Technology Foundation, Wakefield, MAKey words: Gymnodinium breve, growth, toxicity, culture, dinoflagellate, toxicity assay,mosquito fish, Gambusia affinisSummary: Eight 12-liter cultures of Gymnodinium breve were maintained for five months inthis study of population growth and toxicity. Each culture received an estimatedinoculation of 50,000-60,000 cells per liter, but population levels inexplicablydiminished rapidly to 3000-9000 cells per liter shortly after inoculation. Allpopulations, however, reached at least 5 million cells per liter by five weeks (acalculated population growth rate of 0.3/day). Populations varied thereafter,ranging from a half million to 24 million per liter after five months. Cultures wereconsidered replicates, but no cause was apparent for the density variance. Toxicity(determined with the mosquito fish, Gambusia affinis) and bacterial populationlevels varied directly with G. breve cell concentration; the ratio of large to small169

cells was greater in populations with increasing as opposed to decreasingpopulations.Methods: See "Materials and Methods."QA/QC: None per se; see "Materials and Methods."Contact: William B. WilsonSource Inst.: Department of Marine Science, Texas A & M University, Galveston, Texas, USAAuthor: Wyatt, T.Date: 1975Title/Chap.: The limitations of physical models for red tidesBook: Proceedings of the First International Conference on Toxic DinoflagellateBloomsEditor: V. R. LoCiceroPages: 81-93Publisher: The Massachusetts Science and Technology Foundation, Wakefield, MAKey words: physical model, red tide, circulation pattern, vertical stability, advection, diffusion,plankton distibutionSummary: Circulation patterns seen in both shallow water and deep water above a pycnoclineand processes that increase vertical stability in the water column are the two majoroceanographic processes commonly used to address the influence of the physicalenvironment on red tide concentrations. The two may not be distinct and mayoccur concurrently, but making such a distinction may aid understanding of smallscaleoceanographic features that influence plankton population distribution. Thepaper reviews the two processes (advective and diffusive) regarding theirusefulness in understanding the mechnisms affecting red tides apart from those thatare ecological.Methods: None (review)QA/QC: N/AContact: T. WyattSource Inst.: Ministry of Agriculture, Fisheries and Food, Fisheries Laboratory, Lowestoft, NZAuthor: Yentsch, C. S., Phinney, D. A. and Shapiro, L. P.Date: 1989Title/Ch.: Absorption and fluorescent characteristics of the brown tide chrysophyte: its roleon light reduction in coastal marine environmentsBook: Novel Phytoplankton Blooms: Causes and Impacts of Recurrent Brown Tides andOther Unusual Blooms, Coastal and Estuarine Studies 35Editor: E. M. Cosper, V. M. Bricelj and E. J. CarpenterPages: 77-83Publisher: Springer-VerlagKey words: brown tide, chrysophyte, phytoplankton, bloom, absorption spectra, fluorescencespectra, Skeletonema sp., Aureococcus sp.Summary: This study sought to determine if the brown tide absorption and chlorophyllfluorescence spectra differed from typical coastal phytoplankton. Comparisonswere made between the diatom Skeletonema sp. and the brown tide organism,Aureococcus sp. The brown tide, unlike the diatom, indeed selectively absorbed170

lue light in the same region as that for theoretically maximal photosynthesis in seagrasses (450 nm), greatly changing the subsurface light quality. Selectiveabsorbance of blue light is a typical characteristic of oceanic phytoplankton. Usingthese results, the authors speculate that remote sensing could successfully indicatepresence of brown tide-like organisms in coastal waters via fluorescence excitationspectra and/or colorimetry.Methods: See “Methods.”QA/QC: None per se; see “Methods.”Contact: Charles S. YentschSource Inst.: Bigelow Laboratory for Ocean Sciences, West Boothbay Harbor, Maine 04575USA171

XVI. AcknowledgmentsLIST OF CONTRIBUTORS TO CCBNEP REPORT1. Aransas National Wildlife RefugeTom Stehn, BiologistPO Box 100,Austwell, TX 779502. Cameron County Marine Extension ServiceTony Reisinger, Marine Extension AgentCCMES, 650 East Hwy 77San Benito, TX 785863. Florida Dept. of Natural ResourcesKaren SteidingerFlorida Department of Natural Resources,Institute of Marine Research100 8th Ave. SESt. Petersburg, FL 337014. Louisiana State University / LATEX B programSteve Murray, Program Mgr.Coastal Studies Inst., LSUBaton Rouge, LA 708035. Minerals Management ServiceWalter JohnsonDepartment of the Interior, MMS381 Elden St. MS 644Herndon, VA 220706. National Biological ServiceChris OnufSouthern Science CenterCorpus Christi Field StationTexas A&M University-Corpus Christi6300 Ocean Dr.,Corpus Christi, TX 784127. NOAA: National Marine Fisheries ServiceRoger ZimmermanGalveston Laboratory NMFS4700 Ave. UGalveston, TX 77551172

Pat TesterNMFS Southeast Fisheries Science Center., Beaufort Lab.101 Pivers Island Rd.Beaufort, NC 28516-97228. Newspapers:The Brownsville HeraldBox 351, Brownsville, TX 78522-0351The Port Isabel/South Padre PressPort Isabel, TX9. Researchers:William Wardle,Department of Marine Biology,Texas A & M UniversityP. O. Box 1675Galveston, TX 77553Henry Hildebrand (retired.)Quay Dortch,LUMCON8124 Highway 56Chauvin, LA 70344Daniel G. Baden.University of Miami Rosenstiel School of Marine and Atmospheric Science,Division of Biology and Living ResourcesMiami, FL 3314910. Texas A&M University: College StationDr. Frank J. KellyTexas A&M UniversityGeochemical & Environmental Research Group833 Graham Rd.College Station, TX 7784511. Texas A&M University-Corpus ChristiCenter for Coastal Studies and Conrad Blucher InstituteCBI: Nick KrausCCS: Roy LehmanCBI: Chris FawcetteTexas A&M University-Corpus Christi6300 Ocean Dr.Corpus Christi, TX 78412173

12. Texas Department of Health & Human ServicesMike Ordner and Gary HeidemanTexas Dept. of Health, Division of Seafood Safety1100 West 49th Street,Austin, TX 7840113. Texas Natural Resource Conservation CommissionJim Bowman4410 Dillon Lane,Corpus Christi, TX 78415Richard Kiesling, Kelly Hutchinson, Patrick RoquesTX NRCC, Water Quality OfficePO Box 13087, Capitol StationAustin, TX 78711-308714. Texas Parks and Wildlife Dept.Larry McEachron, Science DirectorTX Pks. &Wldlf, Coastal Fisheries DivisionRockport, TX 78382Todd EngelingTX Pks. & Wldlf. Dept.Marine Development Ctr.4300 Waldron Rd.,Corpus Christi, TX 7841815. Texas Water Development BoardDr. David BrockTWDB, Environmental Section611 S. Congress,Austin, TX 7870416. University of Texas Marine Science InstituteKenneth DuntonJoan HoltScott HoltPaul MontagnaDean StockwellTerry Whitledge750 Channel View DrivePort Aransas, Texas 78373174