Heavy metal concentrations in surface water, sediments and fish and their potential toxicity in highly degraded multipurpose peri-urban Eleyele Lake, Ibadan City, Oyo State, south-western Nigeria

Beaven Utete,Bernadette T Fregene,Philip Louis Staddon

doi:10.1080/23311843.2020.1785137

Abstract

Metal concentrations in water, sediments and gills and edible stomach muscle tissues of two fish species, African Sharptooth mud catfish (Clarias gariepinus) and the Nile Tilapia (Oreochromis nilot...

Highlights

Artificial lakes located within their catchments tend to be highly degraded, polluted and have reduced water ecosystem services to sustain livelihoods and aquatic biodiversity (Rosenberg et al, 2000)
The objectives of the present study were to i) assess the spatial and temporal variations in the concentrations of selected metals consisting of iron (Fe), copper (Cu), zinc (Zn), cobalt (Co), cadmium (Cd), lead (Pb), nickel (Ni) and mercury (Hg) in water, sediments and the gills and edible stomach muscle tissues of two commonly consumed fish species, African Sharptooth mud catfish (Clarias gariepinus) and the Nile Tilapia (Oreochromis niloticus), and ii) evaluate the potential ecological risks posed by metals to aquatic organisms in Eleyele Lake located in Ibadan City, Oyo State in south-western Nigeria
Electrical conductivity was high at E1 in April (733.23 ± 100.23 μS/cm) though all recorded values were within acceptable standards (Table 1)

Summary

Introduction

Artificial lakes located within their catchments tend to be highly degraded, polluted and have reduced water ecosystem services to sustain livelihoods and aquatic biodiversity (Rosenberg et al, 2000). Leeward location of lakes within their catchments exposes them to high levels of pollution especially in highly populated and industrialised urban and peri-urban areas (Bernot & Dodds, 2005; Wetzel, 2001). Most urban and peri-urban anthropogenic activities such as manufacturing and agricultural industries discharge highly polluted effluents which pose a hazard to aquatic systems (Magadza, 2003; Thornton, 1990). Among such effluents are highly toxic, persistent and non-biodegradable heavy metals and radicals which tend to be cumulative within the aquatic ecosystem (Alloway, 1990). Eleyele Lake is further exposed to pollution from the various anthropogenic activities such as cassava processing occurring in its watershed (Akinyemi et al, 2014)

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Discussion

Conclusion