1 BIOLOGICAL INDICATORS IN RELATION TO COASTAL POLLUTION ALONG KARNATAKA COAST, INDIA

Marine pollutants in relation to planktonic and benthic organisms were examined at two locations along Karnataka coast, one at Kulai (740 47.74 ” E and 120 55.16 ” N) receiving huge amount of industrial effluents from fertilizer, petroleum and chemical plants along with the sewage discharges. The other site Padubidri (740 45 ” E and 130 10 ” N) is located 20 kms away, which is a typically agricultural and fishing village having no stress of industrial discharges. Although the concentrations of dissolved oxygen (DO), nutrients and trace metals in water and sediment showed marginal differences at these two locations, the concentration of petroleum hydrocarbon (PHC) remained exceptionally high with a maximum of 1523 µg/l at Kulai which is 10 times higher than that at Padubidri (144 µg/l). Biomass and population of phytoplankton and zooplankton showed that the seasonal differences were more conspicuous rather than the regional changes. Macro and meiobenthic population remained high at both the locations during the two seasons. Phytoplankton species indicated that centric diatoms such as Rhizosolenia, Leptocylindricus, Chaetoceros, Thalassiosira and Coscinodiscu