Standing stock of phytoplankton and primary productivity in Penaeus orientalis larval multiplication releasing area of the Xiangshan Bay

The standing stock of phytoplankton (phy.)and primary productivity (pp) in the Xiangshan Bay were observed in 1992.The results showed higher biological parameters in the bay.The average chlorophyll a (chl a) concentration was (3.50±5.93) mg/m³ and the primary productivity (444.5±871.0) mg/(m²·d).The distribution of chl a and productivity showed distinct spatial and temporal patterns in the bay.The continent influence was obvious at the top of the bay, lower seawater exchange and higher stability led to higher standing stock of phytoplankton and productivity.At the bay mouth, seawater and lower standing stock of phytoplankton and primary productivity. The seasonal characters of those parameters were pronounced, in the sequence of spring, summer, autumn and winter.The resups of size-fractionated showed that the average contribution of the nano-and picoplankton(<20μm) to total chl a and productivity were 75% and 87%,respectively, indicating their importance in phyto-plankton community biomass and productivity of the Xiangshan Bay.