Journal de la biodiversité et des espèces menacées

Influence of Sediment Composition, Total Organic Carbon on Benthic Organisms at Pulicat Lagoon: A Case Study

Abstract

Sivaranjani V, Santhanam H and Natesan U

Benthic environments are dynamic habitats where the sediments, the functional building blocks of the habitat, are continually structured by both the organisms living in and on the seabed as well as by the local physical regime. Benthic animals are an important component of the marine ecological realm and play a large part in marine food chains, organic production and the turnover of sediments and nutrients on the ocean floor. Because the sub-littoral seabed is less subject to variations in tides, swell and wind driven surface currents, the soft sediments of this environment are relatively stable (i.e., unchanging) compared to intertidal and shallow near shore substrates. Similarly, their populations are also more stable and diverse. These biological processes are also inextricably linked with physical variables, thus benthic communities are very susceptible to both natural and anthropogenic changes in the topography and sediment matrix.

Inorder to understand the association between environmental variables and benthic communities, the distribution of benthic organisms in the dynamic mixing zone of Pulicat and the surrounding coastal waters has been studied. The sediment samples obtained from Pulicat were analyzed for sediment composition and total organic carbon. Further the benthic organisms were sorted, enumerated and grouped into different communities. Based on the analysis; it was found that the distribution of benthic organisms varied with the differences in sediment composition and total organic carbon. The mixing of wastewaters from Buckingham canal with the waters of the dynamic zone of Pulicat could be a significant factor influencing the distribution of benthic communities.