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 2006River at the SW part of the bay andby local breeze.The researched area ranged fromthis part of the bay, the estuary andthe Miñor River up. A A. minutumbloom was detected on 18 Augustin the middle of the south part of thebay during low tide, reaching up to8·10 5 cells·L -1 , associated withsalinities and temperatures from35.3 to 35.7 psu and 17 ºC to 18.5ºC, respectively. Nevertheless thisbloom was not observed thefollowing day or the next week.Moreover, during the same month aKryptoperidinium foliaceum bloomwas observed in both the estuaryand in Miñor River (2-3 km up). Thisspecies was associated with theestuarine front formed by thesurface freshwater outflow and theentrance of higher densityseawater. It is discussed thatdifferences in the life cycle of thetwo species may be related to thedifferent behaviour and physicalconditions associated with theirblooms.PO.13-66A decade monitoring toxicphytoplankton in Scottish watersSession: PO.13 - Regional eventsE. Bresnan, E. TurrellFisheries Research Services, Aberdeen,ABERDEEN, United KingdomA programme, monitoring thepresence of potential shellfish toxinproducing phytoplankton species, infulfilment of 91/492/EEC, wasoperated by FRS from 1996 to2005. This programme identified anumber of regional hotspots for thepresence of Alexandrium cells alongthe Scottish coast. Over themonitoring period, decreasedAlexandrium cell densities wererecorded during early summer,correlating with lower PSP toxinconcentrations in farmed mussels(Mytilus edulis). Dinophysisacuminata and D. acuta dominatethe Dinophysis population inScottish waters. A change in theratio of abundance of these specieshas been recorded since 2001.Elevated cell densities of D. acutawere associated with increasedclosures of cultivated musselsinferring that this species is moretoxic. Since 1999, extensiveclosures have been enforced inoffshore scallop fishing grounds dueto high concentrations of ASP toxinsin king scallops (Pecten maximus).Transmission electron microscopyof Pseudo-nitzschia species inScottish waters has revealeddiverse populations. In total morethen ten species were identified.Changes in the occurrence of toxinproducing phytoplankton species inScottish waters will be discussed.PO.04-07A test of toxic vs. nutritionaleffects of harmful algae (browntide) on clam larvae andimplications for benthicrecruitmentSession: PO.04 – Food chainsV. Monica Bricelj 1 , Scott P.MacQuarrie 1 , FABRICE Pernet 21 National Research Council, HALIFAX,Canada2 Coastal Zone Research Institute,SHIPPAGAN, CanadaBrown tides of Aureococcusanophagefferens coincide withsummer planktotrophic larvaldevelopment of the commerciallyimportant bivalve, Mercenariamercenaria, in mid-Atlantic USA.This study investigates effects oftoxic and non-toxic A.anophagefferens isolates on larvalgrowth, survival and dynamics of139