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 2006detect potentially harmful algaebefore they impact fish farms.Phytoplankton samples were takenusing a segmented pipe. The mostimportant red tide event of the last20 years occurred in spring/summer2005 and the dominant species wasLingulodinium polyedrum. Amaximum value of 17 500 000cells/L was recorded for this speciesat Salsipuedes, BC, in August, whilevalues of 4 500 000 and 4 990 000cells/L were obtained at PuertoEscondido, BC, in June and July,respectively. In addition to the directimpact on the bottom fauna when L.polyedrum attained a density of 6300 000 cells/L in a shallow area ofEnsenada Bay in June, secondaryeffects were observed. In October,in Ensenada Harbour and CoralMarina, tons of anchovy (Engraulismordax) were infected byAcinetobacter vaumannii and died.Subsequently, unusual tunamortalities occurred in farms atdifferent localities. Paralytic andamnesic shellfish poisoning werenot detected in the dead tuna. TheL. polyedrum bloom could haveplayed a role in these complex toxicoutbreaks.Akashiwo, Alexandrium,Dinophysis, Karenia, Karlodinium,Lingulodinium, Pfiesteria,Prorocentrum and Protoceratium,and to a lesser extent toHeterokontophyta, represented byChattonella, Fibrocapsa andHeterosigma, or Haptophyta, withharmful representatives ofChrysochromulina, Phaeocystis,Platychrysis, Pleurochrysis andPrymnesium. Some species suchas Heterosigma akashiwo andPhaeocystis globosa appearrecurrently and, in many cases, atelevated densities. The remainingspecies appeared in very lowconcentrations or were identified incultures of natural samples togetherwith the dinoflagellates Karlodiniummicrum and Karlodinium sp., andthe haptophytes Prymnesiumparvum, Chrysochromulinabrevifilum, Pleurochrysispseudoroscoffensis andPlatychrysis pienaari. In this study,we present the relationship betweenthe physical environment, withemphasis on haline or thermalstratification, and the presence ofthese harmful species along thelongitudinal axis of the estuary.PO.13-20Harmful flagellates in the NervionRiver EstuarySession: PO.13 - Regional eventsE Orive, A Laza, S SeoaneUniversity of the Basque Country, LEIOA,SpainSeveral potentially harmful flagellatespecies have been identified in theNervion River Estuary, a eutrophicwarm temperate estuary which hasexperienced in the last years amarked improval of water quality.Species belong mostly toDinophyta, including the generaPO.13-61Bloom-forming Pseudo-nitzschiaspecies (Bacillariophyceae) fromthe southeastern coast of Russia:morphology, distribution andtoxicitySession: PO.13 - Regional eventsTatiana OrlovaInstitute of marine Biology,VLADIVOSTOK, RussiaA survey for species of thepotentially toxic diatom genusPseudo-nitzschia was carried out onthe south-eastern coast of Russia:Peter the Great Bay (within the Sea254