Zooplankton studies with special reference to krill Euphausia superba Dana from fishing area 58 of Indian Ocean sector in Southern Ocean

Abstract

Distribution, abundance and species composition of zooplankton collected during the First Indian Antarctic Krill Expedition were studied. Zooplankton biomass values ranged from 9.79 to 303.62 ml 100 m sup(–3) (x bar = 142.14 plus or minus 77.02). High standing stock values were recorded in the study area, where copepods, chaetognaths, euphausiids and salps were dominant taxa. Copepods and chaetognaths formed the major constituents of zooplankton community and comprised more than 70% of zooplankton catch. Swarms of krill and salps were observed during the study period (austral summer), which were the prime cause for high standing stock of zooplankton. The prevailing physicochemical parameters with rich food supply were important factors influencing the geographical distribution of different zooplankton groups. The study revealed that the present investigation site falls under potential krill fishing ground.