Relationship of DDE/ΣDDT in Marine Mammals to the Chronology of DDT Input into the Ecosystem

Abstract

The DDE/.SIGMA.DDT (.SIGMA.DDT = DDT + DDE + DDD) ratios in the blubber of North Atlantic pinnipeds and odontocete cetaceans, as determined by several scientists and surveys, were compiled to obtain a biannual mean series. Conversion of DDT to DDE was interpreted as being due not only to the marine mammals but also to the overall detoxifying activity of the North Atlantic marine biota. The change of these ratios during 1964-1981 was examined and a strong correlation between these ratios and time was found in both groups, which demonstrated that such an index can be tentatively used when assessing the chronology of pollutant input into the ecosystem. An equilibrium value may be reached at the beginning of the next century when the ratio reaches a value of .apprx. 0.60, provided that no new inputs of contaminant into North Atlantic waters exist.