Lead shot incidence in sediments and waterfowl gizzards from Merrymeeting Bay, Maine

Lead shot in bottom sediments from Merrymeeting Bay, Maine, averaged 99,932 shot/ha. More shot (P < 0.05) was present in silt sediments than in sand sediments. Number 6 size shot was the most abundant in all 6 river deltas sampled. Ingested lead shot occurred in gizzards of 6 of 10 waterfowl species. Lead shot occurred in 5.9-8.1% of the black ducks (Anas rubripes) sampled during the hunting seasons of 1976-80. A comparison of 3 gizzard examination methods showed that visual examination of gizzard contents and x-ray examination of contents did not differ in accuracy, but fluoroscopic x-ray examination of intact gizzards was not satisfactory for detecting ingested shot. Projected waterfowl mortality and the effectiveness of the steel shot regulation in reducing lead deposition into the environment are discussed.