Heavy Metals Concentration in Water, Sediment, Plant and Bathygobious soporator from Ologe Lagoon, Lagos State, Nigeria

Ologe Lagoon serves as a major source of drinking water, transportation, agricultural activities and fishing in Lagos State, Nigeria. Since there is no formal control of industrial effluents discharged into the river, it is important to monitor the levels of metals contaminants in it, thus assessing its suitability for domestic and agricultural use. In order to determine this, some physicochemical parameters (Alkalinity, Salinity, pH, Turbidity and hardness) and the levels of five heavy metals (Zn, Fe, Cu,Cd and Pb) of water, sediment, plant and a commercially important fish, Bathygobious soporator from six water bodies namely; Agbara, Ologe, Era, Imude, Morogbo and underbridge was studied. The study was conducted for a period of six months (June 2018 to November 2018) spanning the six sampling stations and also both wet and dry season. Hardness showed significant (p<0.05) seasonal variation while hardness and turbidity showed significant (p<0.05) spatial variation. Fe and Cu exhibited significant (p<0.05) Spatial and seasonal variation respectively in the water column. It was observed that the heavy metal content of the water, fish and sediment have increased over time when compared with previous study of the environment. The spatial and seasonal concentrations of the metals varied significantly (p<0.05) in some of the metals. It was observed that the heavy metal content in the sediment is higher than that in the water, plant and fish which indicates that the sediment serves as a reservoir for heavy metals as reported by previous studies. Most of the values of the physicochemical parameters and heavy metals were within the limit recommended by World Health Organisation, Nigeria’s Federal Environmental Protection Agency and United States Environmental Protection Agency. This study shows that the water quality variables of the water bodies can still sustain fish and the heavy metal content is not harmful to fish and man yet.