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 2006due to pollution from landreclamation and urbanization. Inresponse to growing concerns overthe impact of harmful algal bloomson marine resources, ecosystemsand human health, a survey wasinitiated to study the harmful algaeof the waters of Abu Dhabi Emiratebordering the Arabian Gulf. Aharmful algal bloom was recorded inone of the sampling areas(Mussafah). It had a maximum cellconcentration of 18 x 10 7 cells/L andshowed seasonal variation inspecies dominance: dinoflagellatesduring winter and cyanobacteriaduring summer. The winter bloomwas represented by Prorocentrumspp and the water was brown incolour whereas in summer thebloom was generated byOscillatoria sp., and the water had agreen colour. The hydrographicparameters showed abnormalconditions. Nutrient values weremany folds higher than the normalseawater and confirmed theeutrophic nature. The blooms wereassociated with widespread harmfulimpacts including hypoxic events(0.20mg/L), finfish kills (Nematalosanasus) and subsequent loss ofbenthic organisms. The sources,composition and consequences ofnutrients and bloom formation andspecies dominance in Abu Dhabiwaters will also be discussed.PO.16-01Local importance of resting cystsfor a dinoflagellate bloominitiationSession: PO.16 – Life cyclesS Angles, E Garcés, K van Lenning, AReñé, A PalanquesICM CSIC, BARCELONA, SpainResting cysts are the product ofsexual reproduction ofdinoflagellates and comprise thenormal dormant phase of theseorganisms. Cysts may survive in thesediment for months or even years,and during that time their dispersionand concentration is influenced bymany factors. In the case oflocalized blooms in shallow,restricted embayment or harbours,the coupling between cysts in thesediment and blooms in the water isdirect. Recurrent blooms of the toxicdinoflagellate Alexandrium minutumin the 'Arenys de Mar’ Harbour (NWMediterranean) provided a perfectopportunity to study resting cystdynamics and to evaluate thenumber of cysts that contribute tothe bloom initiation. We quantifiedthe resting cysts of A. minutum andother dinoflagellates in sedimentsamples collected during severalcruises and evaluated their spatialand temporal distribution patternsduring pre- and post-bloomconditions. We also studiedgermination rates of A. minutumcysts at different locations in theharbour. Standard sedimentaryvariables (grain size, coarse andfine fraction, organic and inorganicC, organic N), as well as physicaland meteorological parameterswere considered for interpretation ofobserved variability in cystconcentrations.PO.03-09A water-asssociated dermatitis inSwedish lakesSession: PO.03 - Public healthHeléne AnnadotterUniversity of Lund, LUND, SwedenIn 1999, an outbreak of waterassociateddermatitis in theSwedish Lake Värsjön was found tobe caused by schistosomecercariae using the snail Radix126