Spatial distribution and abundance of zooplankton communities in Lake Victoria, Kenya

Abstract

The study was conducted between January and March 2015 in the Kenyan waters of Lake Victoria. Duplicate composite vertical samples of zooplankton were collected from the water column using 50μm plankton net of 30 cm diameter and preserved with 5% formalin prior to identification in the laboratory. Water quality parameters were also measured in-situ. Cyclopoid copepods (64.7%) dominated the zooplankton community while Rotifers (1.7%) were the least abundant in the lake. A total of 20 zooplankton species were identified under the taxa 9 Rotifer, 6 Cladoceran, 4 Cyclopoid and 1 Calanoid. Multiple comparisons by Tukey test showed no significant difference in zooplankton density among the stations (p>0.05). The highest values of water quality parameters recorded were turbidity 70.52 mgL-1, conductivity 158.72 μS/cm, temperature 27.38oC, Dissolved Oxygen 5.25 mgL-1 and pH 8.06, with corresponding lowest values of 11.09 mgL-1, 93.26 μS/cm, 25.74oC, 4.35 mgL-1 and 7.41. The observations from the study could be linked to the habitat degradation and pollution causing changes in the zooplankton community in Lake Victoria.