Polycyclic aromatic hydrocarbons in sediment and tissues of the crab Callinectes pallidus from the azuabie creek of the upper bonny estuary in the Niger delta

Abstract

The accumulation of Polycyclic Aromatic Hydrocarbons (PAH) in sediment and the flesh/carapace of the edible swimming crab Callinectes pallidus from Azuabie creek in the upper Bonny Estuary, Niger Delta and Nigeria were studied. Sediment and crab samples were collected from three sampling stations along the Azuabie creek in July (rainy season) and November (dry season) 2007. These stations were selected to reflect point of abattoir waste input (which includes ash from tyre used for roasting meat) into the creek as well as locations upstream and downstream of the point. Seasonal and spatialvariations were observed in the concentrations of PAH. Significant differences in PAH (p<0.01) were observed between rainy season and dry season samples. The major classes of PAH found in sediment and C. pallidus were Naphthalene, Benzo (a)pyrene, Benzo (a) anthracene and Phenanthrene which are known to be carcinogenic. The PAHs were higher during the rainy season probably due to run-off of tyre ash from the nearby abattoir. The observations made in this study suggest that C.pallidus from the Azuabie creek might not be safe for human consumption because of the levels of PAHs found in the fleshof samples mostly in the rainy season. The abattoir appears to impact the creek because significantly higher levels of PAHs were recorded at the proximate sampling station. © Maxwell Scientific Organization, 2013.