Spatial-Dynamics of Trace Metals Accumulation and Physicochemical Characteristics in Ikpukulu-Ama Creeks, Rivers State, Nigeria

Abstract

The study examines the spatial-dynamics variability of water parameters and trace metal concentrations between January and June 2023 at the Ikpukulu-Ama sites of the Bonny River, Nigeria. Key parameters analyzed include temperature, salinity, pH, transparency, dissolved oxygen, and trace metals (Ni, Pb, Cd, Cu, Zn) across three sites. The highest temperature, 32.56°C, was recorded at Site 2, indicating potential thermal stress. Salinity peaked at Site 1 (16.23 ‰), reflecting a stronger marine influence, while Site 2 had the highest pH level (6.87), indicating mildly acidic conditions. Transparency was greatest at Site 2 (90.33 cm), indicating lower turbidity. Site 2 also had the highest lead (Pb) levels (0.63 mg/kg). Dissolved oxygen levels were highest at Site 1 (4.55 mg/L), suggesting better water quality. Strong correlations among trace metals suggest common industrial sources. Elevated biochemical oxygen demand (3.6 mg/L) and total dissolved solids (500 mg/L) at Site 2 indicate significant organic pollution and high levels of dissolved substances. Pb concentrations were notably higher at Site 2 (0.63 mg/kg in sediment and 0.33±0.13 mg/L in water). Site 1 showed the highest levels of nickel (Ni) (5.63±1.92 mg/kg in sediment and 0.34±0.05 mg/L in water) and zinc (Zn) (6.15±0.74 mg/L in water), while Site 3 had the lowest Pb and Ni concentrations. Cadmium (Cd) levels were consistently low across all sites. The bioaccumulation and bioconcentration of heavy metals in C. gasar from Site 2 pose ecological and health risks, necessitating continuous monitoring and control of pollution.