Ecological study on planktonic dinoflagellates in inshore of Northern Yellow Sea

The data collected in two surveys in Jun. and Sep.,1998 were analysed. The results show that the number of planktonic dinoflagellates species in the water of Northern Yellow Sea is less than expected , only 8 species .The amount of planktonic dinoflagellates is 50.45% of total phytoplankton in June.The amount of planktonic dinoflagellates is neither positive nor negative correlation with IN and IP. In the water with less contents of nitrogen and phosphorus, some planktonic dinoflagellates are more prosperous than that of planktonic bacillariophyta.