Zooplankton Variability in Polluted and Unpolluted Waters off Bombay

Abstract

Zooplankton abundance in the waters around Bombay was studied at Versova, Bombay Harbour (less polluted), Mahim and Thana (highly polluted) from October 1977 to December 1978. A rich zooplankton population was observed throughout the period of study especially during the low tide with peaks in October/November and March/April. Mean zooplankton dry weight at the different stations were 8.7 mg/100 m3 (Thana), 5.8 mg/100 m3 (Versova), 4.04 mg/100 m3 (Harbour) and 3.84 mg/100 m3 (Mahim). Eventhough numerically Mahim station sustained the maximum population of zooplankton, the recorded mean biomass was the lowest for the area studied. No correlation was found between the population density peak of either the high or low tide of any month among the four stations. Group diversity of zooplankton was relatively more in unpolluted waters than in polluted waters