Long-term variations in benthic macroinvertebrate assemblages off Bombay, India

Abstract

Changes in composition, number, and biomass of macrobenthic infauna in relation to environmental deterioration in the coastal zone of Bombay, India were followed between 1974 and 1983. A time-dependent impoverishment in population density and faunal composition, with total depletion at many sites, was observed. Of the environmental parameters, dissolved oxygen concentration in the near-bottom water and organic matter composition of bottom deposits exhibited major changes, with deleterious effects on the biota. Macroinvertebrate infauna were comparatively more stable in offshore and deeper regions than in nearshore shallow areas. Polychaeta, a dominant taxon in offshore regions, was the only infaunal component of the most heavily affected nearshore region. The gradual deterioration of environmental quality resulting from the ever-increasing anthropogenic perturbation has endangered the marine life