PERSISTENT ORGANOCHLORINE RESIDUES IN SMALL CETACEANS FROM THE EAST AND WEST COASTS OF SOUTHERN AFRICA

Organochlorine pollutant levels in the blubber of small cetaceans and ratios between concentrations of compounds, such as DDE/tDDT and tDDT/ PCB, were used to identity the chronology of input of DDT and PCB into the coastal waters along the west and east coasts of southern Africa. Although regression analyses, with time as the only independent varia ble, do not show a statistically significant decline in tDDT from 1980 to 1987 in the common dolphin from the east coast of South Africa, th ere is a fairly strong indication that tDDT concentrations did not inc rease or even stay constant with time. tDDT concentrations in the bott lenose dolphin declined significantly from 1980 to 1987 (P < 0.05). Th e regression analyses for PCB in the bottlenose dolphin from the east coast show no decline (P > 0.05). The data from this study illustrate that it would take a long time in the coastal waters and open ocean be fore the restriction and prohibition on the production and use of orga nochlorines will take effect.