Metal concentrations in water column, benthic macroinvertebrates and tilapia from Delimi river, Nigeria

Abstract

Concentrations of some metals in the water, benthic macroinvertebrates and the muscle tissue of the Nile tilapia from river Delimi, Nigeria were investigated from January 1998 to June 1998. Samplings were done monthly at 3 different sites. The concentrations of the metals were determined using the atomic absorption spectrophotometer. With the exception of pH, dissolved oxygen, turbidity and biochemical oxygen demand, values of other water physico-chemical parameters monitored were all significantly the same (P > 0.05) within the 3 sampling sites. Metals encountered during the survey include potassium, copper, lead, zinc, cadmium, iron, manganese, magnesium, calcium and sodium. Values of individual metal encountered within each of the sampling sites were significantly the same (P > 0.05). With the exception of manganese, water sample had the lowest values of metal detected. Zinc, copper, lead and potassium were all below detectable levels in the water sample. The presence of copper, lead, zinc and cadmium in the fish is of serious health concern to human consumers. The environmental implications of the results are discussed.


Key words: Metals, rivers, pollution, tilapia, benthic macroinvertebrates.


Journal of Aquatic Sciences Vol.17(1) 2002: 55-59