Assessment of water quality, macroinvertebrate biomass and primary productivity of small water bodies for increased fish production in the Lake Victoria basin, Kenya

Abstract

AbstractThis study investigated the suitability of small water bodies (SWBs) in the Lake Victoria basin, between November 2010 and October 2011 for increased food production through aquaculture. Sampling sites were stratified in terms of water availability and altitude. Low‐altitude sites were represented by Yenga and Mauna dams in Siaya County, while high‐altitude sites were represented by Kesses and Kerita dams in Uasin Gishu County. Variations in selected water quality parameters, nutrients, primary productivity (PP) and macroinvertebrate biomass of SWBs were investigated. The measured biological and water quality parameters measured in this study included PP of phytoplankton, macroinvertebrate biomass of the most abundant taxon, temperature, dissolved oxygen concentration, biochemical oxygen demand, pH, total nitrogen concentration and total phosphorus concentration. Descriptive statistics of mean and standard error of the mean were conducted for water quality parameters and nutrient levels. The general linear model was used to test for significant difference in nutrients and physicochemical parameters, both within and between the SWBs. anova was used to test for any significant differences in both PP and biomass within and between the dams. PP and macroinvertebrate biomass were sufficiently high to support fish production, while all water quality parameters and nutrients were within acceptable ranges to support the life of the mostly cultured species. Based on the results of this study, the stocking of phytophagous and benthophagous fish is recommended as a means of exploiting the food resources and increasing fish production in these areas.