Biodiversity of fauna and heavy metal assessment in selected areas of University of Lagos Akoka Campus, Lagos, Nigeria

Abstract

The biodiversity of terrestrial fauna and assessment of some heavy metals - cadmium (Cd), chromium (Cr), cobalt (Co), lead (Pb), nickel (Ni) and manganese (Mn) concentrations in soil samples were investigated in selected areas of the University of Lagos Akoka campus. Atomic Absorption Spectrophotometer (AAS) was used for heavy metals analysis and biodiversity index was calculated with Margalef, Shanon- Weiner and Simpson index. On the basis of the Shanon- Weiner index, Zoological garden had the highest species richness (2.75) while High-Rise (1.71) had the lowest species diversity. On the basis of the Simpson index (1-D), Faculty of Science had the highest species diversity (0.95) while High-Rise had the lowest diversity (0.75). Formicidae (21.60%), Gecarcinidae (13.77%) and Libellulidae (13.51%) were the families with the highest relative abundance in the
University of Lagos while Cercopithecidae (0.26%), Elapidae (0.34%) and Gryllidae (0.34%) were the families with least relative abundance. The result of the soil texture (particle size) of the various sampled zones indicated that sand is the dominant component with a mix of loam. Heavy metal mean concentrations of the soil samples from the University of Lagos indicated the presence of Pb (0.17 - 29.67 mg/kg), Ni (0.59 - 6.63 mg/kg), Mn
(72.72 - 398.63 mg/kg), Cr (0.01 - 16.23 mg/kg), Cd (0.20 - 0.87 mg/kg) and Co (0.17 – 6.52 mg/kg). All heavy metals detected were below Federal Ministry of Environment (FMEnv) and European Union (EU) permissible limit for heavy metals in soils except Mn. Though, Mn is biologically important with low toxicity, there is need for consistent monitoring of the heavy metals so as not to pose a threat to the biodiversity of the study area.

Keywords: Biodiversity, Heavy metals, Diversity indices, University of Lagos