Deep sea benthos of the western and central Indian Ocean

Abstract

Quantitative investigations on deep sea benthos from 112 stations between lat. 21 degrees N-21 degrees S and long. 51 degrees E-94 degrees E and in the depth range of 1500 to 6000 m, revealed a rich biota having relatively low species diversity in the western and the Central Indian Ocean. Mean population density varied from 23322 m-2 in 1500-1999 m depth zone to 50269 m sup(-2) in 5500-5999 m depth zone. Both macro- and meiobenthos decreased in abundance with increasing water depth. The rate of decrease in faunal abundance as assessed from regression coefficient was high in deeper depths and low in relatively shallow depths. Diverse but rich benthic fauna and high values of standing crop are dependent on high organic production in the overlying water column of the western and the Central Indian Ocean. Correlation between biomass of organic matter in the water column and the benthic standing crop was statistically significant