Diel variations of zooplankton at Kavaratti Atoll (Lakshadweep)

Abstract

Occurrence, abundance and diel variations of major groups and species of zooplankton at 2 stations at Kavaratti Atoll (Lakshadweep) during October 1971 were studied. Zooplankton and water samples, for the environmental parameters, were collected at every 2 hr interval covering the entire tidal cycle. Diel variations in the environmental parameters were not significant except for dissolved oxygen content in the lagoon. Average zooplankton biomass values were higher (140.8 g/1000 m³) for the station outside the coral reef than for the lagoon station (104.7 g/1000 m³). Nocturnal abundance of zooplankton was observed at both stations. Swarms (31496.0/10 m³) of the luminescent ostracod, <i>Cypridina</i> sp. resulted in high zooplankton abundance particularly in the night samples. Faunistic composition was more diverse at sea than in the lagoon.