Evaluation of the Total Hydrocarbon content of some Seafood and Water from the Great Kwa River in Cross River State

Abstract

Hydrocarbon contamination is of great worry because of its widespread effect on all forms of life. Pollution caused by increasing crude oil exploration is of great concern, as well as inadequate refuse disposal problems. Crude oil and petroleum products are among the most common pollutants in the marine environment. This study was aimed at determining the total hydrocarbon content of water, mud, shrimp and periwinkle from the Great Kwa River in Calabar, Cross River State. The water, mud, shrimp and periwinkle were collected from the Great Kwa River in the Calabar metropolis during the rainy season. Total hydrocarbon content was analysed using ultraviolet spectroscopy. From the results, the total hydrocarbon content varied widely across the biomarkers adopted by this study (water 2.28 - 738.31ng/µl, shrimp 46.28 - 60.39ng/µl, periwinkle 0 ng/µl and mud 1.01 - 422.18ng/µl). The three highest concentrations of hydrocarbon components observed in the water are n-pentadecane 738.31ng/µl, n-hexadecane 584.54ng/µl, and n-tridecane 383.00ng/µl. The three least hydrocarbon components observed in the water are n-hexacosane 2.28ng/µl, n-octacosane 4.22ng/µl, and n-dotriacontane 8.91ng/µl. However, n-nonane 60.39ng/µl, and n-decane 46.28ng/µl as observed in shrimps are the only hydrocarbon components that were biotransferable. From this study, it is observed that the hydrocarbon concentrations in the Great Kwa River are quite significant and some of the concentrations are higher than safe levels (both for ingestion and inhalation), hence regular biomonitoring of the River is recommended to check source pollution. In-depth research into their oxidative stress responses, metallothioneins, oxygen affinity and thus, toxicological effects is also suggested.