GIS approach in assessing the status of neritic water quality and petroleum hydrocarbons in Bay of Bengal (From Chennai to Nagapattinam, Tamilnadu), India

Neritic coastal water samples, collected onboard in Ocean Research Vessel (Sagar Purvi, NIOT) at a depth of 15m from the shore in August, 2010 at 15 coastal stations (opposite to the river mouths, fish landing centres and nuclear power station) stretching from Chennai to Nagapattinam, Bay of Bengal, Tamilnadu, were analysed for water quality parameters to find the impact of anthropogenic activities/sea based activities on the coastal water. Significant contribution from the present study reveals that the dissolved oxygen content in the neritic waters ranged from 1mg/l to 5.2mg/l which shows a decreasing trend from north to south direction. Kaliveli coastal water is highly polluted with petroleum hydrocarbon (1772.50ug/l) followed by Ponnaiyar river region, Cooum river region and Puducherry coastal area and the wind direction was found to be mostly towards Southwest and West. The higher concentration of petroleum hydrocarbons at Kaliveli coastal area gives a great concern because it is an important bird area, an important point for winter migrants like Storks (Ciconia ciconia ) and crested pochards. There is a lack of awareness about ecological importance and protection of such wetlands among local people. The present study necessitates continuous monitoring and modeling of petroleum hydrocarbons along with prevailing hydrodynamic conditions in the coastal water which will be useful in improving the health status of marine environment, nearby wetland and associated biota.