Effects of environmental variables on Phytoplankton distribution in Kusalla reservoir, Nigeria

Abstract

The effects of physico-chemical factors on the composition, distribution and abundance of phytoplankton of Kusalla reservoir were studied. Water and phytoplankton samples were collected and analysed using standard methods for a period of one year. Data collected was subjected to analysis of variance, which shows that the phytoplankton has significant seasonal and spatial variation. Correlation analysis show that phytoplankton has significant positive correlation with temperature, conductivity, dissolved oxygen and the nutrients. The phytoplankton was dominated by the Chlorophyta followed by the Cyanophyta. Baccillariophyta and Dinophyta. The lake is adjudged to be tending towards deterioration of water quality. The abundance, composition and distribution of the phytoplankton in Kusalla reservoir is affected by the environmental variables. The physicochemical parameters to a large extent determine the seasonal and spatial patterns of the phytoplankton. The numerical dominance of the Cyanophyta in the reservoir is an indication that autochtonous and allochtonous inputs into the reservoir are decreasing the water quality.