UPTAKE OF ORGANOCHLORINES (CHLOROBIPHENYLS, DIELDRIN, TOTAL PCB AND DDT) IN BOTTLE-NOSED DOLPHINS (TURSIOPS-TRUNCATUS) FROM CARDIGAN BAY, WEST WALES

High concentrations of organochlorine compounds (particularly PCB and chlorobiphenyls) have been found in three bottlenose dolphins from the vicinity of New Quay in West Wales. Although few in number, the anima ls ranged in age from 10 months to 23 years. The occurrence of high co ntaminant concentrations in ah of these animals suggests that a high l evel of uptake of these compounds occurs in food after weaning as well as by transfer from mother to calf. In order to investigate this furt her we have tried to model the uptake using a bioenergetics-based appr oach. Using estimates of feeding rate we have calculated the concentra tions of these contaminants in average prey items necessary to maintai n the dolphin's body burden during the juvenile growth th stage. The d ata available to date are too few for a rigorous test of this approach , however these preliminary studies suggest that the contaminant conce ntrations in local food items analysed to date are not sufficiently hi gh to explain the high concentrations found in dolphin blubber. Furthe r information is needed on the contaminant burdens of bottlenose dolph ins in Cardigan Bay, and of their relationships and diet (including se asonal and migratory components), in order to validate this approach.