Spatial and temporal patterns of phytoplankton composition in Zobe Reservoir, Dutsinma, Katsina State, Nigeria

Abstract

The abundance and distribution of phytoplankton algae in Zobe Reservoir was studied from using (3) sampling stations for a period of eight (8) months.The water was also analysed for Physicochemical attributes which includes Temperature, pH, Dissolved Oxygen, Biological Oxygen Demand, Nitrate-Nitrogen, Phosphate-Phosphorus, Total Dissolved Solids, Transparency and Electrical Conductivity using standard methods. Results showed that the values of physicochemical parameters recorded were of a typical tropical region. Station ‘B’ (middle) has highest number of organisms (284 org/l), followed by station ‘C’ (221 org/l), the least was recorded in station ‘A’ (162 org/l). Physicochemical attributes did not vary significantly among the stations. Four (4) classes of algae were identified which were dominated by Chlorophyta 386(57.87%), followed by Cyanophyta 126 (18.89%), and the least was Bacillariophyta 47(7.05%) represented byTabellaria flocculosa. There were generally high number of algal organisms (Chlorophyta, Cyanophyta, Euglenophyta and Bacillariophyta) observed during the dry season than in the wet season. However, Spirogyra sp.had the highest number of occurrence in all stations (204 org/l) followed by Euglena sp. (109 org/l)and the least was Oscillatoria agardhii (22 org/l). There was positive significant correlation (P<0.05) between algae and physicochemical attributes of the reservoir. The study showed that the reservoir was not polluted and the water is safe for domestic use since the number of harmful algal cells recorded were relatively low which were within the standardof World Health Organization for safe water (WHO, 2003).

Keywords: Phytoplankton, Zobe, Reservoir, Pollution, Cyanophyta.