Meiobenthos of polluted and unpolluted environments of Versova, Bombay

Abstract

Quantitative distribution of meiobenthic faune of Varsova (Bombay, Maharashtra, India) waters was studied at four stations during November, 1979 to December, 1980. The nearshore areas represent a typical polluted environment while stations towards offshore represent relatively unpolluted regions because of their effective dilution and mixing processes. A gradual increase in mean biomass values from nearshore towards offshore was evident. The fauna was constituted mostly by nematodes (52.90%), foraminifera (33.97%), polychaetes (4.05%) and crustaceans (6.15%). Other groups, viz., Radiolaria, Turbellaria, Kinorhyncha, Pycnogonida, Pelecypoda and Gastropoda were occasional inhabitants of the area. During pre-monsoon, higher population density and biomass were obtained from all stations excepting station 2. In monsoon, higher abundance of foraminifera at station 2 contributed to the maximum biomass and population density. Group diversity of meiobenthos gradually increased from nearshore towards offshore. Substratum was clayey-silt generally, except at station 1, where it was almost sandy. At station 1 and 2, a shift in substratum during monsoon was associated with a change in distribution of foraminifera. High values of organic matter were associated with clayey silt bottom