Horizontal and vertical distribution of organic contaminants in deep-sea fish species

Polychlorobiphenyls (PCBs) and pesticides are persistent, semivolatile contaminants whose global circulation is now well established. One of their ultimate sink is the bio- and geo-phases in the deep-sea. We have investigated the distribution of selected PCBs and pesticides with depth and longitude in various deep-sea fish, namely black scabbardfish (Aphanopus carbo), orange roughy (Hoplostethus atlanticus), roundnose grenadier (Coryphaenoides rupestris) and Bathysaurus ferox from Madeira, Sesimbra, the Meriadzec Terrace and Rockall Trough in the North Eastern Atlantic at 1000 m depth, and at 2000 m depth where available. In most species, males presented higher levels of contamination than females. This pattern was probably due to the females eliminating contaminants through egg production. Roundnose grenadier presented higher levels of contamination (mainly p,p′-DDE, CB 153, 138, 180, ∑CB(24) and p,p′-DDT) in fish caught at 2000 m than at 1000 m depth. Similarly, B. ferox, which is found deeper than the other species studied, showed much higher levels of most CBs and pesticides (lipid normalised) than the other species. Concentrations were up to 10 times higher, and showed differences between water masses.