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 2006with salinity. Other spectral regionsof high variation were identified inthe pool of samples and comparedwith fluorescence peaks in theliterature. Although factors did notcorrelate with cell count or presenceof K. brevis, spatial patterns ofoptical properties and salinity wereused to identify the origins ofcoastal water masses and potentialsources of entrained nutrients.PO.10-38Pseudo-nitzschia along thesouth-central coast of Vietnam:abundance, distribution, T-Scharacteristics, and growth rateof cultures and naturalpopulationsSession: PO.10 - Ecophysiology &autecologyHai Doan-Nhu, Mai Anh T Nguyen,TuongGIA Nguyen-NgocInstitute of Oceanography, NHA TRANG,VietnamPseudo-nitzschia species are widelydistributed along the coast ofVietnam with abundance distributionvarying in time and space. Alongthe southern-central coast,however, they tend to occur in highabundance during the rainy season,when nutrient loading fromland/rivers is high. The seasonalvariation shows local differencesdepending on the hydro-chemicalcharacteristics of each embaymentalong the coast. The Pseudonitzschiaassemblages wereobserved as high as 400.000cells/L, which is close to the level ofshellfish harvesting closure inEurope. Temperature and salinitycompared with cell abundanceindicated that Pseudo-nitzschia mayadapt to a wide range oftemperature and salinities. In NhaPhu Lagoon there were at leastthree different Pseudo-nitzschiaassemblages that grew at (1) lowtemperature and low salinity; (2)high temperature and low salinity;and (3) high temperature and highsalinity, while they were stenohalinebut eurytherm in Nha Trang Bayand the northern coast of BinhThuan waters. Pseudo-nitzschiacuspidata isolated from Nha TrangBay showed the highest growth rateat 35 PSU and 30 °C (1.8 d -1 ), butgrew well at a range from 20-30 °Cand 25-35 PSU. This species maybe a representative of the hightemperature and high salinitypopulations in Nha Trang Bay.PO.13-84Toxicity of Pseudo-nitzschia spp.in estuarine and shelf waters ofLouisiana, USASession: PO.13 - Regional eventsQ Dortch 1 , GJ Doucette 2 , ML Parsons 31 NOAA, SILVER SPRING, United States ofAmerica2 Marine Biotoxins Program NOAA,CHARLESTON, SC, United States ofAmerica3 Marine Science Department, University of,HILO, HAWAII, United States of AmericaPseudo-nitzschia spp. arefrequently widespread and highlyabundant in Louisiana coastalwaters. Seven species have beenidentified, including, P.pseudodelicatissima, P.delicatissima, P. multiseries, P.pungens, P. multistriata, P.subfradulenta, and P. brasiliana.Although several of these areknown producers of domoic acid(DA), no human illness has beenreported. In order to determine ifDA was being produced and, ifpossible, by which species andunder what environmentalconditions, DA content wasmeasured in net tow samples (35164