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 2006PO.15-26HAB-MAPS of toxic marinemicroalgae in the ‘Cono Sur’ ofSouth AmericaSession: PO.15 - MonitoringR Akselman 1 , B Reguera 2 , M Lion 21 Inst. Nac. Invest. Des. Pesquero, MARDEL PLATA, Argentina2 Inst. Espanol Oceanografia, VIGO 36200,SpainInformation on the distribution ofharmful microalgal species and theirchanges over time is essential toevaluate if harmful events areexpanding/contracting in a givenregion, and to interpret dispersalroutes. This information is alsouseful for risk assessment andplanning of the exploitation ofmarine resources. The ISSHAproject HAB-MAP was created toestablish a global referenced mapof the known distribution of toxicmarine microalgae species. Herewe present HAB-MAP activities forthe coastal waters of the Cono Surof South America (Brazil, Uruguay,Argentina, Chile, Perú and Ecuador)on the basis of a literature reviewthat comprised 150 publishedpapers and reports. The databasewas developed with Excel-files foreach species; different worksheetsprovided data-sets extracted fromeach bibliographic reference.Factors considered included georeferencedlocation (to allow thegeneration of distribution maps),date, cell abundance, toxin content,harmful effects and relevantenvironmental information. A total of40 toxic species - 9 diatoms, 23dinoflagellates, 3 haptophytes and 5raphidophytes- were recorded. Thetotal number of toxic species couldbe greater than the apparent onebecause of dubious taxonomicidentification of some taxa, and lowfrequency of sampling in largeareas of the Cono Sur.PO.13-44Phytoplankton distribution,diversity and nutrientvariations at the west coastof Sweden, with specialreference to harmful algaeSession: PO.13 - Regional eventsA Y Al-Handal, B Karlson, L Edler, A-TSkjevikSMHI, GOTHENBERG, SwedenSpecies composition, abundanceand distribution of phytoplankton aswell as some major physicochemicalfeatures and chlorophyll aconcentration were investigatedalong the Swedish Skagerrak coast.This study is part of a long-termprogram for monitoring of harmfulalgae along the Swedish coast.Owing to the eutrophic nature of theregion, phytoplankton is moreproductive than diversified. Diatoms,dinoflagellates and some otherflagellates dominate phytoplanktonpopulations. Highest abundancewas in Koljöfjord reaching 3.32 x10 6 cells -1 in May 2005, withdiatoms constituting 69.7%. Lowestabundance was in Kosterfjord inMarch 2006, when cell densitieshad dropped to 11.7 x 10 3 cells l -1 .Diatoms were exceptionally scarceat this station in May 2005 (0.150 x10 3 cells l -1 ) accompanied by adominance of the harmfuldinoflagellate Dinophysis norvegicaand some cryptophytes.Dinoflagellates reached theirhighest abundance of 1.18 x 10 5cells l -1 at Koljöfjord in August 2005.Chlorophyll a reached a minimum of1.1 µg/l in April 2005 (Danafjord)and a maximum of 8.1 µg/l inSeptember (Kosterfjord). A number122