Polychlorinated biphenyl and organochlorine pesticide contamination signatures in deep-sea fish from the Mediterranean Sea

Polychlorinated biphenyl (PCB) and OCP concentrations were determined in the livers of two deep-sea fish species, roughsnout grenadier and hollowsnout grenadier, from the Adriatic Sea. In both species, contaminant concentrations were in the following order: PCBs>DDTs>>HCB. Contaminant load was higher in roughsnout grenadier (PCB: 12,327 ng g−1; DDTs: 5357 ng g−1; HCB: 13.1 ng g−1) than in hollowsnout grenadier (PCB: 1234 ng g−1; DDTs: 763 ng g−1; HCB 6.3 ng g−1). PCB patterns were dominated by higher chlorinated congeners (hexa-CBs: 50.3–52.1%, hepta-CBs: 29.6–35.5%, penta-CBs: 8.0–11.1% and octa-CBs :5.2–5.4%). PCBs 138, 153 180 and 187 were the most abundant. Regarding the DDT pattern, p,p′-DDE was prevalent in both species (roughsnout grenadier: 99.7%, hollowsnout grenadier: 90%), suggesting no recent DDT input. In both species, the total 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalent (TEQ) concentrations (roughsnout grenadier: mean 43.77 pg/g, hollowsnout grenadier: mean 20.49 pg/g), calculated from non- and mono-ortho PCBs, reached those encountered in marine organisms at higher levels in the trophic chain.