The Alaska Department of Fish and Game conducted studies of nearly 600 hunter-shot ducks in upper Cook Inlet during the late 1970s and 1985–1986. Lead pellets in gizzards and elevated lead in liver tissue were found in 27% of mallards and 17% of pintails. Of all birds collected on opening day, 26% contained ingested lead shot. This indicates that shot deposited in previous years is available to spring migrants, local breeders, and young birds raised on these hunting areas. Surveys in other parts of Alaska have found lead in gizzards of 14% of ducks on Minto Flats, high levels of lead in blood of 25% of spectacled eiders and 20% of long-tailed ducks on the Yukon-Kuskokwim Delta, and lead in gizzards of eiders on the North Slope.
Lead shot can be found in ducks at nearly any traditional waterfowl hunting area. Because it does not break down, lead shot persists and continues to harm waterfowl for many years.