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 2006has remained closed due toinsufficient sampling. Due to timelyand effective state responses andthe assistance given by FDA andNMFS, there were no human PSPillnesses despite remarkably hightoxicity in the unmarketed product.PO.06-02Dinoflagellate diversity andabundance in seven Belizeancoral reef-mangrove lagoons: atest of Margalef's MandalaSession: PO.06 - Population dynamicsMA Faust 1 , SR Kibler 2 , RW Litaker 2 ,MW Vandersea 2 , PA Tester 31 Smithsonian Institution, WASHINGTONDC, United States of America2 NOS/National Oceanic AtmosphericAdminis, BEAUFORT NC, United States ofAmerica3 National Oceanic Service, BEAUFORTNC, United States of AmericaToxic and non-toxic dinoflagellatesare abundant in the waters of theBelizean Central Lagoon, AtlanticBarrier Coral Reef MangroveEcosystem. Dinoflagellates arecostal and off shore planktonic, andbenthic species. Most often bloomforming dinoflagellate observed are:Bysmatrum caponii, Dinophysiscaudata, Gonyaulax grindleyi,Peridinium quinquecorne,Gonyaulax polygramma, Gonyaulaxspinifera, Lingulodinium polyedrumand Pyrodinium bahamense var.bahamense. Nineteen bloomformingspecies, and half of thoseidentified are known toxinsproducing species. Network of coralridges of semi-enclosed ponds oftypological diversity and complexecology limit water exchange fromthe lagoon. The unusualhydrography of the mangroveembayments, and nutrient inputfrom natural sources enhancedevelopment of blooms. Bloom ofG. polygramma may reach celldensities of 1-3 x 10 6 l -1 . Dissolvedammonium is the naturallyproduced nutrient at 0.1-6.0 µmol L -1 maintains the blooms ofdinoflagellates. The aboveconditions influence the ability ofcells to concentrate and proliferateinto species-specific blooms thatfavor dominance towarddinoflagellate species. MargalefMandela predicted that marineenvironments with low turbulenceand high nutrient inputs would favordinoflagellates. As a consequencethis species shift may cause alteredfood web dynamics and theprevalence of toxins in the microbialfood chain.PO.07-17Advection, stratification andharmful algal bloom developmentin the southern Benguelaupwelling systemSession: PO.07 - Ecology andoceanographyAL Fawcett 1 , G.C. Pitcher 2 , S.Bernard 1 , A. du Randt 2 , T.A. Probyn 21 University of Cape Town, CAPE TOWN,South Africa2 Marine and Coastal Management, CAPETOWN, South AfricaThe west coast of South Africaexperiences problems associatedwith harmful algal blooms (HABs),which are typically attributed todinoflagellate species. Wind-drivenupwelling, which is a feature of thesouthern Benguela, plays a criticalrole in the algal dynamics of theregion. Physical processesimportant to bloom situations aremixing and stratification, whichaffect species selection; andadvection, which affects bloomtransport, retention and shorelineimpact. Data from a multi-sensor171