Macrobenthos Off Versova (Bombay), West Coast of India, in Relation to Environmental Conditions

Abstract

Hydrographic conditions in the nearshore areas indicated coastal pollution around Versova. Marine environment towards offshore was relatively unpolluted. Benthic macrofauna was chiefly composed of the dominant groups Foraminifera, Polychaeta and others like Crustacea and Pelecypoda. Pennatularia, Nemeritini, Sipunculoidea, fish larvae, etc. were occasional inhabitants and restricted to the offshore unpolluted zone. Biomass was poor and species composition was inhibited in polluted regions, while population density showed fluctuating trend. Similarity coefficient for polychaetes was high (0.81) towards unpolluted offshore regions. Diversity index (H) was greater for both foraminifera and polychaetes at st 1, which was under more pollution stress. The faunal diversity was more in unpolluted clean zone. High population density and biomass of macrofauna were recorded (excluding foraminifera) during postmonsoon. Foraminifera showed preference to sandy or silty substratum while polychaetes preferred muddy (clayey-silt) bottom.