The investigations on the cell abundance, chlorophyll a concentrations and primary production were carried out in the Sanmenwan Bay during the summer of 1994The results showed that there were remarkable characteristics of the regional distribution in the Sanmenwan Bay due to the differences between the geographic environment and the hydrological conditionsThere were higher concentrations of chlorophyll a in the upper area of the bay than those in other regions of the bayChlorophyll a concentrations decreased slowly from the upper area of the bay to outside of the bay Results of the study indicate that primary production in the Sanmenwan Bay is likely regulated by the phosphate and light condition Distributive characteristics of the primary production is similarly to those of chlorophyll a The average chlorophyll a of the surface water was (318±141)μg/dm3Primary production was (2297±1139)mg/(m2·d)The average concentrations of chlorophyll a in the daytime were higher than those in the nighttime at the fixed
