12th International Conference on Harmful Algae

INTERNATIONAL SOCIETY FOR THE STUDY OF HARMFUL ALGAE12 th <strong>International</strong> <strong>Conference</strong> on Harmful Algae, Copenhagen, Denmark, 4-8 September 2006O.20-04Alexandrium fundyense - redtides, PSP shellfish toxicity,salmon mortalities and humanillnesses in 2003-04 –before andafterSession: O.20 - Regional eventsPresentation time: 12:00 - 12:20JL Martin 1,2 , FH Page 1 , MM LeGresley 11 St. Andrews Biological Station, ST.ANDREWS, NB, Canada2 Fisheries and Oceans Canada, CanadaThe Bay of Fundy has a longhistory of Alexandrium fundyenseblooms and annual shellfishharvesting area closures, generallyduring summer months, due tounsafe levels of PSP toxins. Inaddition to shellfish closures,herring mortalities occurred in 1976and 1979, the salmon farmingindustry suffered mortalities in2003-04 and human illnesses haveoccurred through the years.Data on PS toxins in shellfish havebeen collected since the 1940s andprovide an important perspectiveon inter-annual and seasonal A.fundyense patterns. Data indicatethat PSP has been presentthroughout much of the Bay ofFundy since the early 1940s. andthere are consecutive years ofgreater toxicities.Regular phytoplankton samplingsince 1988 shows that A.fundyense cell concentrations aregenerally greatest in the offshoreregions in close proximity to majorcyst deposits and tend to bedispersed through the exposedregions through water movementsand circulation. Highest cellsdensities since 1988 wereobserved in 2003 (8.8 x 105cells•L-1) in the Grand MananIsland area and in 2004 in BlissHarbour (> 3 million cells.L -1 ) andresulted in salmon mortalitiesduring both years. Patterns inshellfish toxicity prior to andfollowing the red tide events arediscussed.O.20-05Dynamics of blooms of cfChattonella verruculosa in theSkagerrak and the KattegatSession: O.20 - Regional eventsPresentation time: 12:20 - 12:40B Karlson 1 , E Almroth 1 , P Andersen 2 , KEilola 1 , M Kuylenstierna 3 , L-J Naustvoll 41 SMHI, Oceanographic services, VÄSTRAFRÖLUNDA, Sweden2 Bio/consult A/S, ÅBYHØJ, Denmark3 Kristineberg Marine Research Station,FISKEBÄCKSKIL, Sweden4 Flødevigen Marine Research Station, HIS,NorwayLarge blooms of cf. Chattonellaverruculosa were observed in theSkagerrak area for the first time in1998. Blooms have occurred in thearea also in years 2000, 2001 and2006. An overview of the bloomevents is presented. The organismmay be an introduced species butreanalysis of preserved samplesshow that it was present in the areain 1993. It now seems to be anestablished species in the area. Theblooms are described usingobservations from ship sampling(cell counts) and satellites. Alsophysical and biogeochemicalmodels are used for describing theevents. Models results indicate thatlow turbulence conditions may bean important factor for bloominitiation.O.20-06Role of short-term climatechange on outbreak andsuccession of large scale HABsalong east Chinese coast in 2005Session: O.20 - Regional events77