Macrobenthic Invertebrates as Coastal Ecological Bioindicators of Environmental Health

Abstract

The distribution of zoobenthic organisms in relation to the textural characteristics of the sediments in five stations (Veli, Varkala, Alappad, Neendakara and Cochin) was studied along the southwest coast of India. Sampling was done during the post monsoon of the year 2011 followed by the pre monsoon and monsoon seasons of the year 2012. The importance of zoo benthic communities in pollution studies is well established. Results revealed that the sediment texture for Veli, Varkala, Alappad and Neendakara was in the order sand > silt > clay while in Cochin it was silt > sand > clay. Organic carbon varied throughout the study and was expressed in the sequence Cochin>Alappad>Neendakara> Varkala> Veli. Wide variations in zoobenthic species diversity was also observed. The sinking range of coastal surface water received ·pollutants routed from fresh water input and these were estimated through the evaluation of &ottom water nutrient characteristics. The present study thus focuses on the concept that the seabed acts as a sink for most of the pollutants entering the marine ecosystem, and the more stable sediments along with their inhabitant fauna give a clear picture of the severity of contaminants. The study has identified Littorina scabra, Modiolus metca/fei and Trochida sp as indicator organisms along south west India .