Water quality and zooplankton of the Ogba River, Benin City, Nigeria

Abstract

Water quality and zooplankton were investigated using standard methods at four stations in the Ogba River, Benin City, Nigeria, from January to April 2008 (dry season) and from May to August 2008 (rainy season). Nigerian water quality standards were used to assess the water quality. There were elevated values of flow velocity, BOD5, sulphate, phosphate, nitrate and sodium concentrations at Station 2, the municipal wastewater entry point, in relation to other stations. Fourteen zooplankton species, including five cladocerans, eight copepods and one rotifer, were recorded, with the quantitative distributions in the order Copepoda > Cladocera > Rotifera. Station 2 had the highest values, 10 taxa and 114 ind. l–1. The water quality parameters were within the acceptable limits of the Nigerian water quality standards, and the zooplankton was normal in abundance and diversity for such an environment.

Keywords:

• abundance
• anthropogenic activities
• composition
• diversity