Studies On The Ecology And Dynamics Of Dinoflagellate Cysts From Daya Bay

Dinofalgellate cysts are an important component of marine palynomorph assemblages, and are useful for the characterization of recent marine environments. The horizontal distributions of dinoflagellate cysts was studied at the three sites of Daya Bay to investigate temporal changes of water quality. The temporal change in dinoflagellate cyst assemblages in the three sites reflects eutrophication in Daya Bay had taken place long time ago and become more serious in recent years. Abrupt increases in the cysts of Scrippsiella trochoidea strongly suggest that it can be used as a useful indicator to eutrophication in Daya Bay.Dinoflagellate blooms are often linked to encystment and excystment. The encystment and excystment dynamics of Scrippsiella trochoidea was studied in Daya Bay. The seasonal occurrence of vegetable cells, the ratio of empty cysts virus contact cysts, the changes of cysts in surface sediment samples and the cysts formation rate was investigated. The formation rate of Scrippsiella trochoidea resting cyst was controlled by temperature, and low temperature enhance the formation of it. The number of temporary cysts increase with the mass yield of vegetable cells. Cyst germation was inversely related to the number of vegetable cells in the -column and reach it's maximum value in Summer.With the active germination rate in Summer and other favorite factors such as temperature, dissolved oxygen, salinity et al., bloom can occur easily.