Journal of the Marine Biological Association of India

Volume 17 Issue 1

Distribution of particulate organic matter in the Bay of Bengal

V. Chalapati Rao and T. S. Satyanarayana Rao

The paper presents an account of the distribution of particulate organic matter  (particulate organic carbon, nitrogen and phosphorus) in the inshore waters of Bay off Bengal off the coast of Waltair for a period of two years (1961 to 1962) and also from the different regions of the Bay of Bengal obtained during March-April, 1933 on board R. V. Anton Bruun in the International Indian Ocean Expedition.

Variations in the monthly average values of the three fractions of the particulate material in the surface water off the coast of Waltair show an almost similer trend. They reveal high values during the peak period of phytoplankton growth in March-April. (Carbon 13.8 µg. at/1, phosphorus 0.15 µg. at/1 in 1961 and 14.8 µg. at/1, 1.0 µg. at/1 , 0.16 µg. at/1 respectively 1962). The somewhat high values of this period are attributed to a minor bloom of phytoplankton as well as to considerable quantity of detritus from river waters brought down to this coast by the southerly current.

During the period of heavy rains along the Waltair  Coast (July and August) there is an indication of an increase in the concentrations of organic carbon and nitrogen but not of  phosphorus. Average values in the surface water of the different region of the Bay of Bengal indicate high content of particulate matter in regions of high productivity for example, off the coast of Burma and the east coast of India during March-April period.

The concentrations of particulate organic matter in general is low in the Bay of Bengal when compared to other fertile areas of the Pacific and the Atlantic thus reflecting perhaps, the low productivity of this region.

Date : 30-04-1975