Abstract

A study pertaining to diurnal variations of water quality parameters were carried out in three different coastal ecosystems Mandapm jetty (MJ), Seagrass meadows (SG) and coral reef (CR) i.e. sites (site1, site 2 and site 3) of Gulf of Mannar (GoM) for the period 24 hours from the month of September 20 to 21, 2016. The various physicochemical parameters like water temperature, salinity, pH and dissolved oxygen of the different environments are the main factors to influence the water quality of the selected study sites. The water temperature (WT°C) varied from 28.44 to 32.30°C, salinity ranged between 35.89 to 40.28 ppt, pH measured as from 7.98 to 8.48 and dissolved oxygen varied from 3.72 to 8.58 mg/l respectively. The recorded value of chlorophyll a ranged between 0.36 to 1.32 mg/m3 from three sites during the study period. From the three different ecosystems, seagrass ecosystem constantly influences the variation of physicochemical parameters from other two ecosystems. The physicochemical variations of coastal region are including wide range of spatio-temporal variations in selected ecosystems (sites).

Keywords: Gulf of Mannar; Physicochemical; Diurnal; Parameters; Ecosystems