Locational differences in metal concentrations in feathers of Australasian gannet (Morus serrator) in New Zealand

Levels of lead, cadmium, mercury, selenium, manganese and chromium were examined in breast feathers of Australasian Gannets (Morus serrator) from New Zealand waters, where they breed on coastal rocky stacks, islands, and occasionally coastal headlands. There were significant differences in the concentrations of all metals except mercury, with gannets from Ninety Mile Beach having significantly lower levels of all metals than those from the other beaches. Ninety Mile Beach is on the northern tip of the North Island, away from urbanization and industrialization, whereas the other beaches are closer to Auckland, the largest city in New Zealand. The levels of most metals were similar or lower than those reported for feathers from elsewhere around the world. Mercury, however, was at the high end, being exceeded only by raptors and gulls from industrialized countries. Several metal levels were highly correlated, indicating that gannets were usually exposed to several metals at once.