First report on OH-PAHs in South African Clarias gariepinus bile from an urban impacted system

Abstract

The concentrations of selected hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) were determined in the bile of the African sharptooth catfish Clarias gariepinus from impoundments in the urban impacted Klip River system in Soweto, South Africa. Fish were sampled from three impoundments (Lenasia, Fleurhof, and Orlando dams) during the early high-flow season (September/October) of 2013. Biliary OH-PAHs were analysed using a high-pressure liquid chromatograph coupled to a tandem mass spectrometer (HPLC-MS/MS). Seven of the thirteen targeted metabolites were present in the fish of Soweto. The ΣOH-PAHs ranged between 0.1 and 1 876 ng ml⁻¹, with greatest ΣOH-PAH mean at Orlando (947 ng ml⁻¹) followed by Fleurhof (371 ng ml⁻¹). The most dominant metabolite in the sampling area was 2–,3–OH fluorene, ranging between not detected and 1 429 ng ml⁻¹, with the greatest mean at Orlando (709 ng ml⁻¹). PAH metabolites quantified in C. gariepinus most likely originated from the sediments. The hepatosomatic index of the C. gariepinus increased proportionally with the biliary OH-PAH concentrations. To the authors’ knowledge this data on biliary OH-PAH for fish is the first for South Africa.

Keywords: Freshwater toxicology, Klip River, sharptooth catfish, Soweto