The total effects of the physical as well as the biotic factors on the ecosystem is discussed. During the wet season, the salinity drops appreciably while during the dry season it is high again and reaches in places to 35%. During the rains water temperature increases and during the winter period it falls. Hekton, plankton, phytoplankton and zooplankton grow in abundance. The higher and lower levels during the rainy season and the wet period respectively have positive effects in influencing the environment. The coastal water is affected by the interaction of the terrestrial mangrove forest and the sea. The coastal water of the Bay of Bengal is subjected to constant water pollution and is the region where the ecosystem is jeopardized. The chlorinated hydrocarbon concentration is higher in the sea water than in the south eastern cost. There is an abundance of snails and oysters in the south eastern cost than in the south eastern waters. Human activities, land cultivation and the continued use of various chemical fertilizers threaten to pollute the waters of the bay. The oil spills in the southern part of the bay and the industrial wastes of the coastal zones may also be similar threats to its water. The study was made to monitor, assess, and investigate this aspect of the bay.

The following types of pollutants were discussed: (1) oil pollution from oil spills and oil slicks; (2) industrial wastes; (3) solid waste and garbages; (4) domestic sewage discharge; (5) insecticide pollution; (6) nutrient pollution; (7) heavy metal pollution; (8) river discharge silt; and (9) the extent of pollution. To control marine pollution, suitable monitoring system, coastal guard system and some other measures were recommended.