Distributional characteristics of surface-layer mesozooplankton in the Bay of Bengal during the 2005 winter monsoon.

Abstract

Present study consists spatial patterns in biomass, abundance and composition of mesozooplankton in Bay of Bengal. Surface samples were collected from a central open ocean transect along 88ºE and western coastal transect during the 2005 winter monsoon. During the sampling period, both sea level- and sea surface temperature anomalies inferred from satellite imagery were the lowest at the southern stations of the western Bay transect. These anomalies coincided with the highest biomass and abundance of zooplankton, of copepods in particular. Western region was richer in biomass and abundance compared to the central waters. Zooplankton community comprised 28 taxonomic groups. Predominant copepod community exhibited low species richness with just 46 identified species. They were evenly distributed over stations and their diversity did not vary much between oceanic and coastal transects. Copepod Undinula vulgaris was common in the oceanic waters and Temora stylifera in the coastal. This study highlights the occurrence of pockets of dense zooplankton biomass in the moderately productive (primary) bay.