Primary Productivity of the Bay of Bengal During August-September 1976

Abstract

Primary productivity was measured at 29 stations in the Bay of Bengal during the south-west monsoon of 1976 together with related parameters like phytoplankton counts, chlorophyll a, pheophytin, particulate organic carbon, inorganic phosphate and nitrate. Primary productivity in the offshore area (219.79 mg C/m2/day) was relatively less than in the shelf (294.8 mg C/ m2/day) and slope (315.43 mg C/ m2/day) areas. At all the stations (except No.115) the productivity at the surface was maximum relative to the sub surface layers. The season under study was move productive compared to the premonsoon season. Concentration and distribution of pheophytin (6.45 mg/ m2) and particulate organic carbon (11967 mg/ m2) from the Bay of Bengal were reported for the first time. Phytoplankton analysis showed that diatoms contributed 70%, flagellates 23% and dinoflagellates 7% to the biomass at the surface.