Lead and cadmium accumulation in eggs and fledgling seabirds in the New York bight

We measured lead and cadmium concentrations in eggs and in the breast feathers of fledglings of common tern (Sterna hirundo), roseate tern (S. dougallii), Forster's tern (S. forsteri), black skimmer (Rynchops niger), and herring gull (Larus argentatus) nesting in mixed‐species colonies in the New York Bight in 1989. Metal concentrations in fledgling feathers represent in part metals sequestered in the egg by females and accumulation from food brought back to chicks by parents, and thus may be a measure of local metal acquisition. There were significant interspecific differences in lead in eggs, and lead and cadmium in fledgling feathers. Herring gulls had the most lead in eggs (up to means of 6,740 ng/g, dry weight), whereas the terns had the least (mean of 318 ng/g, dry weight). Cadmium concentrations were generally low in all examined eggs (<22 ng/g, dry weight). Lead concentrations were high in fledgling feathers (up to 4,090 ng/g, dry weight) in some populations of all species. Cadmium was highest in fledgling feathers of herring gull and skimmers. Among fledgling terns, the roseate tern (a federally endangered species) had the highest concentrations. For all species except herring gull, the feathers of fledglings had higher levels of metals than did eggs.