BBC: Scientists were surprised by the relatively high concentrations of pollutants like PCBs and PBDEs in deep sea ecosystems. by Paul Rincon
'Used widely during much of the 20th Century, these chemicals were later found to be toxic and to build up in the environment.
'The team led by Dr Alan Jamieson at the University of Newcastle sampled levels of pollutants in the fatty tissue of amphipods (a type of crustacean) from deep below the Pacific Ocean surface.
'The animals were retrieved using specially designed "lander" vehicles deployed from a boat over the Mariana and Kermadec trenches, which are over 10km deep and separated from each other by 7,000km.'
"Bioaccumulation of persistent organic pollutants in the deepest ocean fauna" by Alan Jamieson, et al, here