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 2006triangular in A. peruvianum andrectangular with a left extension inA. ostenfeldii, the presence of thesepeculiar toxins in both species couldbe an indication of a possiblesynonymy.PO.15-29Development of real-time PCRassays for the detection ofCylindrospermopsis raciborskiiSession: PO.15 - MonitoringM S Fuentes, J J Rick, J L Noel, J ABaezaUniversity of Louisiana at Lafayette,LAFAYETTE, United States of AmericaBlooms caused by toxic blue-greenalgae have repeatedly producedepisodes of wild and domesticanimal illness and death. Since2002 the toxin producingCylindrospermopsis raciborskii isfrequently abundant from summerto fall in the Caernarvon/BretonSound Estuary in Louisiana, posinga potential risk of a bloom of thisspecies in that area. Recently(10/04) the species was detected inabundant biomasses in the wholeAtchafalaya Basin. Monitoring theseareas for the presence ofCylindrospermopsis is essential inassessing the potential for bloomformation. However, detection andquantification of Cylindrospermopsisis sometimes problematic,especially if individual chains lackthe characteristic terminalheterocyst.To circumvent this problem wedeveloped a real-time PCR assayfor rapid detection of the species. Inthis assay, detection of amplifiedtarget DNA requires annealing offluorescent-labelled probes,resulting in added level of specificitycompared with assays based ontraditional PCR methodology. Thissensitive technique detects evenlow densities of this speciesinstantly, allowing the creation ofreal-time species abundancedistribution maps, enablingmanagers to respond immediatelyto increases in biomass of thisharmful species and for timelynotification of possible health risksto the publicPO.13-57Summer Alexandrium catenellabloom and the impact on fishfarming, in the XI region, ChileSession: PO.13 - Regional eventsClaudio G Fuentes Grünewald, AAAguilera Belmonte, A Clément DíazPlancton Andino LTDA., CASTRO, ChileDuring the summer of 2005 and2006 a bloom of Alexandriumcatenella was observed in thenorthern inland sea of the XI region.This species is well known as aPSP producer. Unusual behaviourof caged salmon and high A.catenella abundance, more than356 cells/mL in surface waters atthe fish farm, indicated damage tothe fish gill and caused a serioussalmon kill at the site.The cells were distributed mainly inthe upper surface layer, numbersdiminishing with depth. At one sitelocated in the GuaitecasArchipelago (ca. 44º lat. South) themaximum concentration was 961cells/mL, representing 86 % of thetotal phytoplankton community. Thebloom began in December 2005,and the maximum abundance of A.catenella was observed during the2nd and 3rd week of January. At allsites with positive presence of thedinoflagellate the sea temperaturewas higher than 12.0 ºC.175