Comparative assessment of bioaccumulation of some heavy metals in water and mudskipper (Periophthalmus barbarous) of Woji Creek, Port Harcourt, Nigeria

Abstract

The indiscriminate discharges of anthropogenic effluents containing heavy metals from the surrounding residential buildings and industries into Woji Creek are alarming and of environmental concern. This research thus aimed to compare the bioconcentrations of Lead (Pb), Cadmium (Cd) and Chromium (Cr) in the water and mudskippers (Periophthalmus barbarus) of Woji Creek to ascertain their suitability for human consumption. Samples of  water and mudskippers were analyzed for these heavy metals using Atomic Absorption Spectrophotometer between October 2019 and September 2020.  Water and P. barbarus samples were collected from three locations and transported to the laboratory for heavy metals analyses. The results showed that  Pb, Cd and Cr concentrations (mg/L) in water were 0.741±0.550, 0.80±0.034 and 2.867 respectively, while that of fish (mg/Kg) were 3.554±0.91, 2.083±0.91  and 4.987±0.60 respectively. All the heavy metal concentrations studied exceeded the permissible limits of FMEnv and WHO. The hierarchy of heavy metal  concentrations in both water and fish was Cr>Pb>Cd. All the metals studied exhibited significant (P<0.05) higher values in water in the dry season  than wet season except Cr, while in fish, all were higher in the wet season than in the dry season except Pb. The bioconcentration factor showed that P.  barbarus has a high potential to concentrate heavy metals in their body. The study showed that Woji Creek is under stress, and its P. barbarus is heavy  metal-contaminated and unsuitable for human consumption. The study, therefore, recommends that there should be proper biomonitoring to avoid  indiscriminate anthropogenic activities in the area.