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 2006Because of the sanitary risks andenvironmental problems caused bytoxic phytoplankton species,surveys and detection of theseorganisms are now a focus area forscientists and marine exploitation.In Tunisia a monitoring programwas launched in 1995. For theshellfish area in the Gulf of Gabes,we defined 17 sampling stationsgenerally known for eutrophication,and more than 35 stations in opensea.The toxic phytoplankton along thesecoasts is limited to 4 dinoflagellatespecies (Alexandrium minutum,Prorocentrum lima, Protoceratiumreticulatum and Karenia selliformis),Karenia selliformis being the mosttoxic during the ten years ofmonitoring. This species is widelydistributed along the coasts,especially in the Bougrara Lagoonwhere we frequently observe redtides.PO.13-23Remarkably high level of domoicacid detected in a bivalveSpondylus versicolor in VietnamSession: PO.13 - Regional eventsViet Ha Dao 1 , Takata Yoshinobu 2 , SatoShigeru 2 , Yasuwo Fukuyo 3 , MassakiKodama 21 Institute of Oceanography, NHA TRANG,Vietnam2 Kitasato University, IWATE, Japan3 University of Tokyo, TOKYO, JapanRecently, we reported that asignificant level of domoic acid (DA),a causative toxin of ASP, occurs inthe bivalve Spondylus collectedfrom various parts of tropical areas,including Vietnam. DA-producingorganism(s) therefore probablyoccur widely in tropical areas. In thepresent study, we detected DAaround the safety consumption level(1.93 + 1.29 μg/g, n=3) inSpondylus versicolor collected fromNha Phu Bay on May 30th, 2005.Thirty specimens were thereforereared in running filtered seawaterin an aquarium, and the change ofDA level in the specimens wasanalyzed. During 18 weeks ofrearing, no significant decrease ofDA level was observed, suggestingthat this species maintainsaccumulated DA for a long period.On September 29th, 2005,specimens of the same speciescollected from the same areashowed remarkably high levels ofDA (109.47 + 47.66 μg/g, n=10),which is much higher than thesafety consumption level. DA inthese specimens was mostlyconcentrated in the digestive gland.The results suggest that DA of S.versicolor originates frommicroorganism(s) ingested by S.versicolor. Probably, the causativeorganism of DA shows a seasonalbloom pattern. Further surveys ofDA in plankton species in tropicalwaters are required.PO.03-05The situation of ciguatera fishpoisoning in French Polynesiafrom 2000 to 2004Session: PO.03 - Public healthH T Darius, T Revel, A Ung, P Cruchet,M Tchou Fouc, M ChinainInstitut Louis Malarde, TAHITI, FrenchPolynesiaCiguatera Fish Poisoning (CFP) iscaused by the ingestion of tropicalreef fish which have bioaccumulatedciguatoxins in theirtissues. This phenomenon is wellknown by local people particularly inremote archipelagos of FrenchPolynesia where the population stilldepend on fish resources.This work presents the situation of158