Changes in water quality parameters and their effect on zooplankton distribution in a shallow bay of Lake Victoria, Kenya

Abstract

Lake Victoria’s shallow bays are increasingly becoming vulnerable to degradation whose effects are manifested ecologically. The influence of water quality parameters on zooplankton distribution in four stations at Kisumu Bay of Lake Victoria in Kenya was estimated. Selected physic-chemical parameters were measured in-situ, while water samples for Chlorophyll a determination were collected. Zooplankton was sampled using conical plankton net. The shoreline station 1 exhibited significantly higher mean zooplankton species diversity and abundance (H’=2.23; 12.65±25.21 ind. L-1 respectively) compared to the offshore stations. Copepoda were the most abundant zooplankton across all the sampling stations while Rotifera constituted the highest species diversity with 14 species followed by Cladocera with 7 species. There were significant relationships between zooplankton abundance and water quality parameters. This study indicated that the water quality conditions observed may have resulted in suppression of some zooplankton species and favored species-specific abundance at the same time.