Physicochemical characteristics and benthic faunal constituents of a few seagrass and mangrove habitats of Tuticorin coast, Gulf of Mannar

Rapid industrialisation and coastal developmental activities have caused considerable damages to the coastal habitats and their associated fauna and flora of Tuticorin coast. The status of the physicochemical and biological aspects indicating the healthiness of selected seagrass and mangrove habitats of Tuticorin coast was studied during 2013-15. The water and sediment quality parameters and the benthic in-faunal constituents were assessed monthly adopting the standard procedures. Our study indicated that the mangrove habitat was profoundly impacted due to the influence of high saline effluents from neighbouring salt pans. The mean values of most of the water quality parameters like salinity (37.87±1.86ppt); chlorophyll-a (8.2±2.95mg.m-3); TSS (529.6±47.13mg.L-1) ammonia (0.12±0.02µg.L-1); nitrite (1.96±0.92µg.L-1); phosphate (8.67±2.58µg.L-1) were reported abnormal from the mangrove habitats. The seagrass habitat was impacted mainly by the activities of the neighbouring port, causing comparatively higher total suspended solids and dissolved solids in the water. Parameters like, DO, salinity, chlorophyll, TSS, NH3 , NO2 , SiO3 in seawater and coarse and fine sand proportions of sediments were significantly varied between habitats (p<0.05). The lower density and less diverse in-faunal constituents also proved the harshness of the sediments of both the habitats. The study also warrants the need for effective management strategies for conservation and the sustainable utilisation of these resources.