Pages: (38-68 )
Abstract
The impact of sawmill wood wastes on the distribution and abundance of fish species at Okobaba area of Lagos, Lagos state, Nigeria was investigated from April to September 2021. A total of 791 species were recorded representing eighteen families of twenty three species. Three stations were selected from upstream of the site receiving wood wastes discharge, the impacted site and its downstream, respectively. Physico – chemical characteristics and some metals of Okobaba was also studied. The most abundant species was the blackchin tilapia, Sarotherodon melanotheron. The species’ richness was 0.82. The dominance index for the study period was 0.09, the species Shannon-Wiener Index (Hs) is 1.15, the species equitability index (J) was 0.85 and the species evenness (E) was 0.62. There was a positive correlation between the fish abundance and biomass (r=0.34). The results from the digestion of metals from the stations showed that metals induce stress on fish species and also affect the distribution of the fishes. These metals also alter the biochemical properties of the fishes from the study site. High mean levels of the biochemical profile in the blood samples were recorded at serum triglyceride at 3.50 mmol/l, total serum protein at 110.92g/l, serum albumin at 43.95g/l, AST at 179.60 u/l, ALT at 77.85 u/l, ALP at 24.65 u/l , urea at 4.02 mmol/l, creatinine at 40.98mmol/l, sodium at 155.58 mmol/l, potassium at 24.02 mmol/l, calcium at 2.48mmol/l, and phosphorus at 6.30 mmol/l. High mean levels of antioxidants activities SOD at 5.44 µmol/ml/min/mg, CAT at 30.84 µmol/ml/min/mg, GSH at 72.77 µmol/ml/min/mg and MDA at 6.11µmol/ml/min/mg indicating an adaptive and protective response in fish towards exposure to an oxidative inducing xenobiotic. The findings of the present study have emphasis that wood wastes from sawmills pose negative impacts on the health of aquatic biota and ecological receptors.
Keywords: Pollution, Oxidation, Trauma, biochemical-examination, biodiversity,