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 20062 Delaware Biotechnology Institute, UD,NEWARK, United States of AmericaDelaware’s Inland Bays (DIB),Delaware, USA are subject tonumerous mixed blooms ofraphidophytes each year.Heterosigma akashiwo is aconsistently occurring pleomorphicraphidophyte that blooms within awide range of salinities andtemperatures. In the summer of2004, a unialgal bloom with adensity of 200 million cells per literwas detected in low salinity water.Initial analyses via light microscopyled to the misconception that thespecies was H. akashiwo, howevermuch smaller than other fieldobservations in the region. Furthermolecular analyses of the 18SrDNA sequence indicated that thisspecies is a novel raphidophyte,and phylogenetic analyses placethe new species withinRaphidophyceae as a new genus.Although this species ismorphologically very similar to H.akashiwo under light microscopy,transmission electron and confocalmicroscopy revealed distinct shapeand size differences in chloroplastsand some organelles. Althoughlaboratory experiments indicatedthat this new species growsoptimally in low salinity water,pigment analysis indicates thepresence of both fucoxanthin andviolaxanthin, which arecharacteristic of marineraphidophytes.PO.13-08Ecological analysis of harmfulalgal blooms for the Bohai Seaarea, ChinaSession: PO.13 - Regional eventsBP Di 2 , Danling Tang 1 , SF Wang 2 ,Jianhai Lv 1 , GM Zheng 21 Chinese Academy of Sciences,GUANGZHOU, China2 South China Sea Institute of Oceanology,GUANGZHOU, ChinaBohai Sea is a semi-enclosed seain northeastern China, whereharmful algal blooms (HABs) breakout frequently and cause largeeconomic losses. The present studyanalyzed spatial and temporaldistribution, causative species ofHABs and ecological conditions inthe Bohai Sea for the period from1950 to 2004, and discussesrelevant environmental factors.HABs increased in frequency andaffected-areas with peaks in 2001and 1999. The dominant causativespecies was Skeletonema costatumbefore the 1990s and Noctilucascintillans after 1992. The highblooming season was July-Augustin the 1980s and 1990s and itshifted to June-August during 2000-2004 for the entire Bohai Sea.Results show Dalian Bay and BohaiBay to be two high-HAB frequencyareas, and differences in high timingand frequency occurrence of HABsare due to local meteorology,nutrient and species. The increasein occurrence frequency andaffected-areas of HABs are relatedto increase in eutrophication, but theimproved methodology andimproved monitoring enable moreHAB to be identified.PO.13-90Aquaculture development andpotentially harmful microalgaein SenegalSession: PO.13 – Regional eventsAnis DialloCentre de Recherches Océanographiquesde Dakar-Thiaroye (ISRA/CRODT), Parc161