Variation in physicochemical and hydrocarbon concentration in callinectes sapidus and macrobrachium malcolmsonii from Bolo Creek, River State
This study investigated the bioaccumulation of selected heavy metals and petroleum hydrocarbons in two commercially and ecologically important aquatic species, Callinectes sapidus (blue crab) and Macrobrachium malcolmsonii (prawn). Twenty blue crabs and prawns were collected with nets while, water and sediment samples were collected in 250 mL glass bottles and with 10 X 10 cm Eckman Grab from three impacted and one reference sampling locations respectively. Water quality parameters including heavy metals and hydrocarbons contents were analysed using standard methods. Data were analysed with SPSS V. 23.0 software. Mean concentrations (mg/L) of Zn (0.022±0.0039), Cd (0.002±0.0005), Cr (0.001±0.0002), Pb (0.0005±0.0002), Mn (0.0008±0.0003), total petroleum hydrocarbons (TPHs; 32.975±3.932) and total polynuclear aromatic hydrocarbons (ƩPAHs; 6.350±0.808) were lower in water than sediments (17.880±2.261, 1.488±0.259, 1.818±0.265, 3.603±0.662, 0.0275±0.006, 55.133±8.584, 22.749±3.970 mg/kg respectively) at the impacted location. Mean accumulations (µg/g) of Zn (9.00±1.80), Cr (1.14±1.01), Cd (0.13±0.05), Pb (0.03±0.01), Mn (0.33±0.14), TPH (3.62±0.57), PAH (0.11±0.03) and BTEX (0.03±0.01) were higher in combined tissues of C. sapidus at the impacted locations than at the reference locations (1.25±0.09, 0.03±0.01, 0.01±0.001, 0.002±0.001, 0.003±0.001, 0.004±0.001, 0.002±0.001 and 0.001±0.0002 µg/g respectively). Mean accumulations (µg/g) of Zn (10.02±2.97), Cd (2.16±2.02), Cr (0.21±0.052), Pb (0.43±0.01), Mn (0.64±0.05), TPHs (4.41±0.52), PAHs (0.16±0.38) and BTEX (0.05±0.12) were higher in combined tissues of M. malcolmsonii at the impacted locations than at the reference locations (1.33±1.53, 0.43±0.12, 0.01±0.002, 0.001±0.001, 0.003±0.001, 0.003±0.002, 0.001±0.001 and 0.0003±0.0003 µg/g respectively). This underscores the potential long-term health implications of consuming contaminated aquatic resources from Bolo Creek. There is an urgent need for continuous environmental monitoring and effective pollution control strategies in the area to mitigate ecological degradation and public health risks.
Keywords: physicochemical, hydrocarbon, callinectes sapidus, macrobrachium malcolmsonii Bolo Creek, River State.
