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 2006that P. donghaiense has a numbverof nutrient-utilizing systems and lownutrient-adapting mechanisms,which may aid during competitionwith other phytoplankton speciesunder low nutrient environment.PO.13-48Pseudo-nitzschia and ASP in thenorthern Adriatic SeaSession: PO.13 - Regional eventsG Honsell 1 , C Dell’Aversano 2 , FVuerich 1 , S Sosa 3 , L Tartaglione 2 , ATubaro 31 University of Udine, UDINE, Italy2 University of Naples, NAPLES, Italy3 University of Trieste, TRIESTE, ItalyThe presence of domoic acid inmussels grown in Northern AdriaticSea has been recently reported.Although Pseudo-nitzschia specieshave been abundantly found inphytoplankton, forming springsummerand autumn blooms,taxonomical information on thisgenus including domoic acidproducers are generally lacking. Forthis reason, a survey on Pseudonitzschiawas carried out in the Gulfof Trieste in 2005 based onphytoplankton qualitative andquantitative analysis, taxonomicalidentification by TEM and ASPtoxins analysis. The most abundantspecies were Pseudo-nitzschiacalliantha (54420 cells/L) andPseudo-nitzschia delicatissima(20840 cells/L), as previouslyobserved also in Southern AdriaticSea. Some clones of these speciesare known to produce low amountsof domoic acid, such as 0.007-0.221pg/cell and 0.005-0.12 pg/cell,respectively. Consequently, theconcentration of amnesic toxinsboth in natural phytoplankton netsamples and in seawater was underthe detection limit of both BiosenseASP ELISA (10 pg/ml) and HILIC-MS (3 ng/ml in MRM positive ionmode transition at m/z 312>266).These results confirm that Pseudonitzschiacalliantha and Pseudonitzschiadelicatissima are the mostcommon Pseudo-nitzschia speciesin the Adriatic Sea, although theirinvolvement in ASP toxinsproduction has to be demonstrated.Thanks to Friuli Venezia GiuliaGovernment for funding thisresearch.PO.16-07Alexandrium cysts in PugetSound, Washington, USASession: PO.16 – Life cyclesRA Horner 1 , CL Greengrove 1 , JRPostel 1 , JE Gawel 1 , KS Davies-Vollum 1 ,A Cox 2 , K Sorenson 1 , J Hubert 1 , SHoffer 1 , J Neville 1 , BW Frost 11 University of Washington, SEATTLE,WASHINGTON, United States of America2 Western Washington University,BELLINGHAM, WASHINGTON, UnitedStates of AmericaParalytic shellfish poisoning is oftencommon in shellfish throughoutmuch of Puget Sound, but little isknown about the distribution ofeither the motile cells or cysts of themajor causative species,Alexandrium catenella. A survey of32 sites in the spring of 2005showed that cysts are present insurface sediments throughout PugetSound, being most abundant in thenorthern and central areas. SequimBay in the north with 200 cysts/mlsediment and Quartermaster Harborin the central part with 12,000cysts/ml sediment have the highestabundances. Elsewhere wherecysts were found, numbers rangedfrom < 10 to about 100 cysts/ml.There appears to be no correlationbetween sediment grain size andcyst abundance. Cyst abundance193