Is PCBs concentration variability between and within freshwater fish species explained by their contamination pathways?

► We study PCB contamination pathways to explain within- and between-species variability. ► We test the role played by feeding habitats by an improved SIA approach. ► Only three variables explain 80% of the variability observed in PCB concentrations. ► PCB levels increase with the exploitation of detrital carbon sources. ► What fishes eat is less important in the contamination pathway than where they feed.