PH25 Wildlife Ecotoxicology II
Exhibit Hall
8:00 AM - Thursday
(PH300) Lead shot availability to birds in the North Platte River adjacent to a trap and skeet range.
Dickerson, K.1, Farag, A.2, Harper, D.2, Gray, A.1, 1 U.S. Fish and Wildlife Service, Cheyenne, WY, USA2 U.S. Geological Survey, Jackson, WY, USA
ABSTRACT- Most studies involving lead poisoning as a result of lead shot from either hunting or shooting clubs have occurred in wetlands. This unique study was done to determine the potential availability of lead shot to birds utilizing a flowing riverine system. A trap and skeet shooting range gun club is located on the North Platte River, below the Guernsey Reservoir in Wyoming. In 1999, we obtained sediment samples to determine if lead shot from shooting activities was present and potentially available to waterfowl and eagles. We collected 25 sediment samples, each consisting of the upper 10 cm of sediment, every 1.5 m along transects that paralleled the river bank and skeet range. Sediment was sorted using a series of sieves. Ninteen of the 25 samples contained at least one lead shot (range = 1-14 lead shot/sample). Our estimate of lead shot pellets per acre of river bottom may range from 522,700 to 7,300,000. Areas with >20,000 lead shot pellets/acre is the suggested density threshold for lead poisoning problems in waterfowl. In 2003, we intensified our study by taking 300 sediment samples. We also recorded each sample location with a Trimble Pro XRS GPS unit. The data was plotted using Asset Surveyor to show the distribution and density of lead shot. Samples of clay pigions were collected and analyzed for cadmium arsenic, and selenium that can leach from the orange paint used to mark the pigeons. We also collected peripyton, sediment, invertebrates, and fish for metal analyses to determine if dietary items have accumulated metals that might pose a threat to waterfowl and eagles feeding from the river.
Key words: waterfowl, lead shot, riverine, clay pigeons