A total number of 46 samples were collected from the open wells during post monsoon season in and around the Tuticorin city to evaluate the water quality and scrutinize the hydro chemical characteristics. Quality assessment is done by estimating the pH, electrical conductivity, temperature, major cation (Na+, K+, Mg2+, Ca+ ) and major anions (Cl-, HCO3-, PO4-). The irrigation quality parameters like sodium absorption ratio, %Na, residual sodium carbonate, residual sodium bicarbonate, chlorinity index, permeability index and magnesium hazard were appraised.

Present paper summarizes the occurrence of C. riisei in coral reefs of Indian seas, its likely impacts on the indigenous biota and policies for bioinvasion in the Indian context. With the limited information available on marine bioinvasion in tropical countries, especially in India, there is an urgent need of study on the occurrence and impacts of invasive species on the coral reef environment as this ecosystem harbors 25% of total marine biodiversity and contribute 10% fishery production.

Dynamics of heavy metals such as Fe, Mn, Zn, Cr, Cu, Co, Ni, Pb, and Cd in surface water of Mahanadi River estuarine systems were studied taking 31 different stations and three different seasons. This study demonstrates that the elemental concentrations are extremely variable and most of them are higher than the World river average. Among the heavy metals, iron is present at highest concentration while cadmium is at the least.