Some aspects of the limnology of Nguru lake, northeastern Nigeria

Aspects of physico-chemical factors and zooplankton of Nguru Lake were studied for a period of twenty four months between May 2006 and April 2008.With the aim of acquiring the necessary knowledge for management of lakes in semi arid areas of Nigeria. Using standard methods.  Nguru Lake, which is part of the Hadejia-Nguru Wetlands, is a natural lake, with an area of about 58,100 hectares and depth of between 1.5m to 7m. Of all the physico-chemical parameters studied only temperature, pH and sulphate concentration showed significant seasonal variation (P<0.001). However all the physico-chemical parameters exhibited highly significant spatial variations (p<0.001). The concentration of metals was in the following order Mn> Zn> Fe> Ca> Mg> Cu. Pearson’s product moment correlation coefficient between conductivity and other physical properties of the lake indicated a highly positive significant correlation. The zooplankton of Nguru Lake was made up of four groups, Cladocera (41%), Copepoda (24%), Rotifera (27%) and Protozoa (18%). There was a total of 16 species with Moina and Keratella dominating the fauna. The zooplankton showed significant seasonal and spatial variation (P<0.001).The lake is gradually tending towards eutrophication.