Journal of the Marine Biological Association of India

Macrozooplankton biomass in the deep scattering layer of the Indian EEZ

Volume 51 Issue 1

P. K. Karuppasamy, S. Balu and Vimala Persis

Abstract

The surveys conducted on board FORV Sagar Sampada during 1998-2002 on the Deep Scattering Layer (DSL) revealed a wide spectrum of macrozooplankton in the sonic layers of the oceanic and pelagic realms from surface to 750 m depth. The macrozooplankton biomass was 6.83 and 9.21 g/1000 m3 in the Arabian Sea and 2.14 and 2.61 g/1000 m3 in the Bay of Bengal, respectively, in the day and night hauls. Bathymetric studies showed that the plankton biomass was high at 0-50 m depth. Out of 19 groups of zooplankton from the Arabian Sea, medusae dominated the catch in day (35.6%) and night (31.4%) hauls. Out of 20 groups in the Bay of Bengal, medusae (36.8%) predominated in the day and euphausiids (32.0%) in the night. This paper shows the distribution and abundance of macrozooplankton along the various depths and seasons, including their diurnal vertical migration.

Keywords

Deep scattering layer, macrozooplankton, biomass, diurnal vertical migration

Date : 27-08-2009