Study on the mechanisms of blooming and geographical expansion of toxic dinoflagellates in Southeast Asian waters

点击翻译按钮获取中文摘要

Various research results were obtained through the establishment of a network with scientists of Southeast Asian countries such the Philippines and Vietnam.1. Expansion of blooming area of red tide speciesRed tide causative species in Southeast Asia are Noctiluca scintillans and Pyrodinium bahamense, which is known as PSP toxin producer too. In addition to them Ceratium furca, Prorocentrum minimum and Cochlodinium polykrikoides became common widely. Mass mortality of wild and culture fish occurred due to their blooming. Phylogentical analysis showed that these newly bloomed species have same characters as those occurring in temperate area. Differentiation of red tide by a toxic species from those by a harmful species to aquatic resources, but not to people, became important for management of seafood sustainability.2. Microalgae causing toxin contamination in fish and shellfishIn addition to Pyrodinium bahamense that bloomed widely, several species such as Gymnodinium catenatum and Alex … More andrium minutum have been detected as paralytic shellfish toxin producers recently at various locations. Toxin contamination and poisoning are found at the same area and time of the blooming of these newly found species. Several species of Dinophysis, known as diarrhetic shellfish toxin producer, such as D. caudata are found also in Southeast Asian waters, but their toxin productivity could not be confirmed. Nitzschia navis-varingica, amnesic shellfish toxin producer, collected in Vietnamese and Philippine coast waters, were analyzed on their toxin productivity, and most of them showed positive results. In the preliminary survey distribution of the species was found quite wide in Asian waters.3. Future research directionELISA kits for detection of various types of toxins have been developed and invented recently. Using the kits it became possible for one scientist to analyze biological and chemical property of certain organism simultaneously. This situation makes detection of toxin producer much easier. Less