The deep-sea as a final global sink of semivolatile persistent organic pollutants? Part I: PCBs in surface and deep-sea dwelling fish of the North and South Atlantic and the Monterey Bay Canyon (California)

The understanding of the global environmental multiphase distribution of pe rsistent organic pollutants (POPs) as a result of the physico-chemical prop erties of the respective compounds is well established. We have analysed th e results of a vertical transport of POPs from upper water layers (0-200 m) to the deepwater region (>800 m) in terms of the contamination of the biop hase in both water layers. The contents of persistent organochlorine compou nds like polychlorinated biphenyls (PCBs) in fish living in the upper water layers of the North Atlantic and the South Atlantic, and at the continenta l shelf of California (Marine Sanctuary Monterey Bay and its deep-sea Canyo n) are compared to the levels in deep-sea or bottom dwelling fish within th e same geographic area. The deep-sea biota show significantly higher burden s as compared to surface-living species of the same region. There are also indications for recycling processes of POPs - in this case the PCBs - in th e biophase of the abyss as well. It can be concluded that the bio- and geo phase of the deep-sea may act similarly as the upper horizons of forest and grasslands on the continents as an ultimate global sink for POPs in the ma rine environment. (C) 2000 Elsevier Science Ltd. All rights reserved.