Investigations on selected ecological parameters of Tuticorin Bay, Gulf of Mannar, south-east coast of India with emphasis on suitability for mariculture

Abstract

A study was conducted for a period of two years from 2017 to 2018 to assess the health of Tuticorin Bay, south-east coast of India. Water and sediment quality parameters, total clam density, heavy metal content in the sediment and clam tissue samples from four sites were used as the criteria for health assessment. High values of parameters like salinity (38.3±5.04 ppt) and ammonia (0.09±0.04 mg l-1) were observed at the station close to the thermal power station and high nitrite (0.688±0.13 µg l-1) and total suspended solids (380.3±0.04 mgl-1) were observed at the station close to Koramballam freshwater creek. Most of the water quality variables were within the standard limit prescribed for aquaculture activities. The organic matter content in the sediment of the bay ranged from 0.26 to 5.17%. Comparatively low heavy metal concentration was observed both in the sediment and clam tissue samples. The metals were found accumulated in the order of Fe>Mn> Pb>Cu>Ni>Cd in the sediment samples and in the order Fe>Pb>Mn>Cu>Cd>Ni in clam tissue samples. The estimated levels were also within the permissible limits for most of the metals. The study indicated that Tuticorin Bay is suitable for mariculture activities.

Keywords: Clam density, Heavy metal concentration, Tuticorin Bay, Water and sediment quality parameters