Impact of water and sediment qualities on the benthic communities of Punnakayal, Roche park and Thirespuram coastal waters of Tuticorin South east Coast of India

Tuticorin is an industrial city located in the south east coast of India and it receives untreated sewage and industrial effluents. The present investigation was carried out to find out the changes in physico-chemical and biological parameters including fecal coliforms of Thirespuram coastal waters, Roach Park and Punnakayal estuary of Tuticorin coast to assess its impact on the benthic communities of these areas. Among the various parameters, salinity was low during monsoon at certain stations due to the river run off. Turbidity, TSS and fecal coliforms were high in water and sediment samples, dissolved oxygen and benthic population were lower, at certain stations where the discharge of untreated sewage and domestic waste disposal were found to be abundant. Untreated sewage and domestic waste have been observed to increase the turbidity, TSS, nutrients and induce fecal coliform growth and reduced dissolved oxygen. These factors are found to affect benthic population of the study sites in the Tuticorin coastal region.