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 2006were compared to those from alivefreshsubsamples analysed at thesame time. In addition, livesubsamples were kept in the dark attwo different temperature conditions(at 15 ºC and 4 °C); they wereanalysed one and two months afterthe samplings.The results have providedinformation about which storageand/or fixation methods to use ifcysts from sediment samples haveto be stored for longer periods.PO.05-36Determination of paralyticshellfish toxins in seafoodSession: PO.05 - Toxin analysisSJ Sayfritz 1 , E Lundanes 2 , J Aasen 1 , TAsp 1 , T Aune 11 Norwegian School of Veterinary Science,OSLO, Norway2 Chemistry Department, University of Oslo,OSLO, NorwayParalytic Shellfish Poisoning (PSP)represents a real threat to the healthof shellfish consumers. The PSPtoxins (saxitoxin group) are a groupof naturally occurring neurotoxinsthat specifically block the excitationcurrent in nerve and muscle cells byblocking the sodium channels. Thiscan lead to paralysis if a largeenough dose is consumed. TheHPLC-FLD method based onOshima, 1995, is currently in use atthe Norwegian School of VeterinaryScience for the analysis of PSPtoxins. However, this method hasbeen shown to be susceptible toinference peaks from a variety ofdifferent seafood matrixes. Theposter will outline an improved SPE(solid phase extraction) basedclean-up procedure for the completeremoval of major chromatographicinference peaks. An improvedextraction technique will also bepresented.PO.14-01Potential role of clay in mitigatingChesapeake Bay algal bloomsSession: PO.14 - MitigationKG Sellner 1 , EF Brownlee 2 , SG Sellner 31 Chesapeake Research Consortium,EDGEWATER, MD, United States ofAmerica2 Hood College, FREDERICK, MD, UnitedStates of America3 Morgan State University ERC, ST.LEONARD, MD, United States of AmericaBecause of increasing concern foralgal blooms in Chesapeake Bayand proximal coastal bays,laboratory studies were undertakento examine the removal of severalbloom species through the additionof treated kaolin clay. Prorocentrumminimum, Chattonella subsalsa,and a small coccoidcyanobacterium were grown in thelaboratory and exposed to 0.9 gclay L -1 . In vivo fluorescence (IVF)was measured on 4 replicates foreach taxon (control and treated)before clay additions, 2.5 h afterclay addition, and 4 d later. Therewas a significant decrease in IVF inall clay treatments with largestreductions in IVF noted forProrocentrum and Chattonella (99%and 92%, respectively) within 2.5 hof the addition; there was no furtherdecline in IVF over the next fourdays. For the cyanobacterium, claywas not as effective, removing only61% and 38% of total cells over the4 d when initial densities were 10 9and 10 8 cells L -1 , respectively.These results suggest that treatedkaolin may be an effective mitigationstrategy for flagellates common toBay blooms whereas coccoidcyanobacteria may persist followingclay additions.276