Distribution of zooplankton in relation to water movements in Kakinada bay, east coast of India

Plankton collections were made from three stations in the bay to study the annual variations in distribution of zooplankton in relation to temperature, salinity, turbidity, pH and dissolved oxygen. The annual mean value of biomass and numerical abundance at three stations were 1.79, 1.80, 2.91 ml.m(-3) and 38482, 39269, 38447 no. m(-3) respectively at three stations. The prevailing northerly and southerly currents along the coast also influence the distribution of the planktonic organisms. In spite of these wide fluctuating conditions we can distinguish characteristic populations within the bay region which show regular annual cycles and colonization. Marked depletion in the number of species was observed during the last 2-3 decades on account of deterioration of water quality of the bay, which is known to receive effluents from the adjacent industries and city.