Coastal water characteristics along Tamil Nadu, east coast of India during pre-northeast monsoon period

308-318A study was carried out to characterize the coastal waters along Tamil Nadu during the pre-northeast monsoon period. A significant spatial variation in coastal water characteristics with respect to physico-chemical parameters was observed, indicating the different level of anthropogenic influence at different study sites. Sampling locations near to the mega city Chennai (Ennore and Pattinapakkam) showed relatively high concentrations of almost all the nutrients due to significant anthropogenic inputs in terms of house hold wastes and industrial effluents through the Adyar and Cooum rivers. A clear decreasing trend in nitrate and phosphate was observed from the northern to southern region of the study area, typifying the signature of pollution in the northern regions. Positive correlations among all the nutrients indicated their common source of origin through external input by the river estuaries and backwaters. Cluster analysis clearly established the presence of a polluted zone (near to Chennai), a buffering zone (Kovalam and Kalpakkam) and a least effected environment in the southern region (Marakanam, Poombukar, Pondicherry and Parangipettai) of the study area