Nutrients input into Ekulu River, Nigeria: Implications on Algal Bloom

Abstract

This study investigated the potential of nutrients input into Ekulu river to cause unwanted growth of algae that could adversely affect the aquatic ecosystem. The concentrations of nitrogen, silicon and phosphorus in the water column of Ekulu river were determined in addition to determining the pH, electrical conductivity, total dissolved solids, total organic carbon, dissolved oxygen, biochemical oxygen demand and chemical oxygen demand following standard procedure by APHA (1998). The results show that there was increase in concentration of phosphorus, nitrogen and silicon in the rainy season. The N/P ratios varied from 6.2-15.7 indicating the possibility of nitrogen being the limiting nutrient as ratio values are less than the optimum value of 16. The Si/N ratio for both dry and wet seasons varied from 2.7-9.1 indicating that Si input into the river is adequate and favourable to the growth and development of diatoms rather than non-diatom phytoplankton species such as dinoflagellates. Consequently, there is no significant risk of eutrophication at the present level of nutrients and silicon in Ekulu river.