RELATION BETWEEN DIVERSITY OF PHYTOPLANKTON AND ENVIRONMENTAL FACTORS IN WATERS AROUND NANRI ISLAND

Based on the investigation in waters around Nanri Island in spring and autumn of 2011, we analyzed spatial and temporal changes in species, abundance and diversity index of phytoplankton, and explored the relation between phytoplankton community structure and environment. The result showed that 106 species of phytoplankton, in 48 genera were identified, wherein diatom was the dominant species in abundance. Abundance in spring was significantly higher than that in autumn, ecological groups feature eurythermal and warm water species. Investigation showed that the heterogeneity of the marine environment of was high, and phytoplankton species diversity was low. Salinity and nutrients, as two major factors that influenced temporal and spatial variation of phytoplankton distribution abundance, were significantly correlated with phytoplankton abundance in spring. Compared to islands survey data during 1990-1991, dominant species were mainly few species, which succeed from domination of both dinoflagellate and diatom to domination of diatom.