1. INTRODUCTION
India has a long coastline of 8,129 km and of this 6,000 km is rich in estuaries, creeks, brackish water, lagoons and lakes. The southeast coast of India is an important stretch of coastline, where many major rivers drain into the Bay of Bengal and they are also richer in marine fauna than the western coast of India. The Chennai coastal region is a distinctive example for numerous recreational and commercial activities that not only degrade the quality of coastal water but also pose a serious health hazard to marine biota and man (Tran et al.,2002; Beiras et al.,2003; Palanisamy et al.,2006).
Estuarine areas are complex and highly changing environments at the interface between freshwater and marine aquatic ecosystems. Despite
The ChennaiMetropolitan Area (CMA) can broadly be divided into three parts. The northern part lies above the Cooum River,middle region is between Cooum and Adayar Rivers and the southern portion is below Adayar River. Due toencroachment along the banks of these rivers and non-enforcement of the laws pertaining to protection of water bodiesand fragmentation of responsibilities amongst the agencies, the effect of flooding tends to be severe. Developmentalactivities along stream channels can reduce the capacity of the channel to convey water and can raise the level of flow.This results in flooding due to heavy rains with the water overflowing and inundating surrounding habitations (Suriya and Mudgal,
These groups have in common a shell whose outline is elongated and asymmetrical compared with other edible clams, which are often more or less rounded or oval. The word “mussel” is most frequently used to mean the edible bivalves of the marine family Mytilidae, most of which live on exposed shores in the intertidal zone, attached by means of their strong byssal threads (“beard”) to a firm substrate. A few species (in the genus Bathymodiolus) have colonised hydrothermal vents associated with deep ocean ridges (Beth et al.,2004; Subba Rao,