Distribution and source apportionments of polychlorinated biphenyls (PCBs) in mariculture sediments from the Pearl River Delta, South China

► Mariculture sediments had higher concentrations of PCBs than natural sediments. ► The average enrichment percentage was 62.0% and 42.7% in surface and core sediments. ► Fish feed input was probably the main source for the enrichment of PCBs.