Quantitative studies on benthic macrofauna of north-eastern Arabian Sea shelf

Abstract

Quantitative distribution of macrobenthos of the north-eastern Arabian Sea shelf (between lat. 24° and 16° N and long. 74° and 66 ° E) has been studied. Mean value of benthic biomass in this region is 7 gm-2. Distribution of biomass shows a gradual decrease with depth. A decline in benthic biomass is also noticed in a north-south direction. Nine different faunal elements of macrobenthos exhibit patchey distribution in relation to depth and area. Polychaetes followed by bivalves form an important faunal assemblage. Dominance of sestonophages on the inner shelf and of detritophages along the middle and the outer shelf indicates a greater abundance of food. Some environmental factors such as nature of substratum, dissolved oxygen and suspended organic matter, seem to play an important role in the distribution of macrobenthos.