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 2006Channel area. Field data from the2004 and 2005 bloom seasons arepresented. These data sets provideevidence to show that the interannualvariability of these blooms isdirectly related to the physicalregime, namely temperature andlight levels within the water columnand tidal dilution. Results oflaboratory experiments investigatingthe effects of both temperature andlight on the growth rates of A.minutum and A. tamarense, speciesthat co-exist within the NorthChannel, are presented. Thecontrol by tidal dilution in the NorthChannel varies substantiallybetween spring and neap tides. It isthe balance between the maximumgrowth rates, as determined bytemperature and light, and the tidaldilution, as determined by the timeof year, that dictate the initiation,intensity and duration of theobserved blooms.O.18-02Eutrophication and HABs- aglobal change perspectiveSession: O.18 - Ecology & Oceanography 1Presentation time: 09:30 - 09:50PM Glibert 1 , S Seitzinger 2 , RWHowarth 3 , JM Burkholder 41 Horn Point Laboratory, CAMBRIDGE, MD,United States of America2 Instit. of Mar. and Coastal Sci, Rutgers,NEW BRUNSWICK, NJ, United States ofAmerica3 Cornell University, ITHACA,NY, UnitedStates of America4 NC State University, RALEIGH, N.C.,United States of AmericaEutrophication-related HABs aregrowing in frequency, duration andtoxic impacts in many parts of theworld. The past several decadeshave witnessed a dramatic increasein the availability of nutrients onland, in the atmosphere and in theocean. This increase is the result ofrapid growth in world population,and in the use of syntheticfertilizers, the development ofconcentrated animal andaquaculture operations, and thecombustion of fossil fuels. Thisincrease is especially apparent fornitrogen, as rates of application ofnitrogen fertilizers have increasedmuch faster than those ofphosphorus, and has led to anaccelerated nitrogen cycle globally.Although there are multiple reasonsfor the global expansion in HABs,and relationships betweeneutrophication and HAB proliferationare complex and not equallyapplicable to all species, thepatterns of proliferation of manyHAB species mirror the increase inapplication on, and export of,nitrogen from many regions of theworld. Of increasing concern arethe projections that 1) humanpopulation growth will bedisproportionately in many coastalregions, and 2) global climatechanges will lead to increasedprecipitation in many of thesenitrogen-rich regions, increasingnitrogen export and thus thepotential for further HAB blooms.O.18-03Thin layers of Pseudo-nitzschiaspp and the fate of Dinophysisacuminata during an upwellingdownwellingcycle in a GalicianriaSession: O.18 - Ecology & Oceanography 1Presentation time: 09:50 - 10:10B Reguera 1 , L Velo 1 , S González-Gil 1 ,P Gentien 2 , M Lunven 2 , C Bechemin 2 , LFernand 3 , R Raine 41 Instituto Español de Oceanografía, VIGO,Spain2 IFREMER, BREST, France3 CEFAS, LOWESTOFT, United Kingdom4 The Martin Ryan Institute, NUIG,GALWAY, Ireland70