Spatial and Temporal Variation of Zooplanktonic Fauna Composition and Distribution in the Jakara-Getsi River System, Kano, Nigeria

Abstract

This study aimed at assessing the spatial and temporal variation of zooplanktonic fauna composition and distribution in the Jakara-Getsi River system, Kano. Sampling was conducted monthly for 12 months (January, to December, 2009). Three sampling sites were selected, they are: Sampling Site A: Jakara River, Sampling Site B: Getsi River and Sampling Site C: Magami (Confluence). Zooplankton Samples were collected using plankton net by vertical haul. Samples were put into labeled 100mL bottle. Water physicochemical parameters determined were temperature, pH, transparency, dissolved oxygen (DO) and 5-day biochemical oxygen demand. Electrical conductivity (EC) were conducted according to standard operating procedures, readings obtained were recorded and consequently analysed. Results showed highest species richness of 20 spp recovered at site A, with higest zooplankton density of 691.28 org/L, while lowest species richness was recorded at site C, 13 species with zooplankton density of 443.19 org/L. Species richness accrdig to taxa showed highest was highest among the Protozoa with 12 spp., with lowest species richness of one specie each among the Rotifera, and nematode. There is observed bimodal fluctuation in zooplankton density at the three sites. At site A, double maxima were recorded in the months of February and December, 199.3 org/L and 109.77org/L respectively. At site B, there were observed maxima in the months of February and April, 138.22 org/L and 60.97 org/L respectively. Kendall’s tau-b correlation between physico-chemical parameters was positive between DO and transparency at P≤0.05 (2-tailed). There was negative Kendall’s tau-b correlation EC and pH at
P≤0.05 (2-tailed). There was also positive correlation in zooplankton density between sites A and B at P≤0.05 (2-tailed), likewise between sites A and C at P≤0.05 (2-tailed).

Keywords: Jakara-Getsi, physico-chemical, spatial, temporal, zooplanktonic fauna