Lead in the diet and body tissues of dunlins, Calidris alpina, from the Bristol Channel, UK

Lead concentrations were determined in the organs of a shorebird, the dunlin, in its main invertebrate prey, and in sediments collected from five sites in the Bristol Channel. The highest sediment concentrations were found in the Taff Estuary (97 μg g −1 dry mass). The highest concentrations in invertebrates were found in the upper Severn Estuary (45 μg g −1 dry mass in Nereis diversicolor). In dunlins, the highest concentrations were found in the sternum (25 μg g −1 dry mass in males), followed by the beak, legs, kidney, liver and pectoral muscle. Adult males contained significantly higher concentrations ( ca 20%) than adult females, and in some cases adults had significantly higher concentrations than first year birds (36% higher in the case of the sternum). Lead concentrations tended to increase throughout the winter, being 37–115% higher in the spring. Birds were able to purge themselves of a substantial portion of their body lead burdens, probably during the autumn moult.