Analysis of Benthic Dinoflagellate Gambierdiscus, Ostreopsis andProrocentrum Density in West Coast of Sumatera Island and Bintan Island Coast in Riau Archipelago, Indonesia

Abstract

Field experiment was conducted in Pulau Pesumpahan and Pulau Pisang Coast ofWest Coast of Sumatera Island and in Malang Rapat and Teluk Bakau Coast of Bintan Island coast, Riau Archipelago to examine the density of benthic dinoflagellate Gambierdiscus, Ostreopsis and Prorocentrum. The density was observed by field experiment using plastic screen. Four field stations (P. Pasumpahan and P. Pisang in the west of Sumatera Island waters, and Malang Rapat and T.Bakau in the east site of Sumatera island waters) were established. The results showed that the role of nutrients toincrease number of dinoflagellates, including Gambierdiscus, Ostreopsis anapat and Prorocentrum is unclear. Increase of dinoflagellate including benthic dinoflagellate Gambierdiscus, Ostreopsis and Prorocentrum may be indirectly as an effect of degradation of coral reefs, and increase of HAB including benthic dinoflagellate may be controlled by macroalgae and seagrasses.