Water Birds at Risk from Heavy Metals in the Great Salt Lake

Eared Grebe. Photo: Dave Herr, USDA Forest Service

A Report on the Great Salt Lake, Utah, presented at the 10th International Conference on Salt Lake Research on May 12, indicated that selenium and mercury inputs to the lake are resulting in elevated levels that are killing brine-shrimp in some areas. Selenium and mercury are becoming concentrated in birds wintering or breeding on the lake at very close to toxic levels. The selenium and mercury find their way into the lake from public water treatment, industrial, and mining operations.

The Great Salt Lake is an Important Bird Area that has some of the highest waterbird concentrations in the world. It is the largest migration stop over site for Wilson’s Phalaropes, has most Snowy Plovers, and has the world’s largest California Gull and White-faced Ibis colonies. The lake supports between 2 and 5 million shorebirds, as many as 1.7 million Eared Grebes, and hundreds of thousands of waterfowl during spring and fall migration. Because of its importance to migratory birds, the lake was designated a part of the Western Hemisphere Shorebird Reserve Network in 1992. The lake and its marshes provide a resting and staging area for the birds, as well as an abundance of brine shrimp and brine flies that serve as food.

Snowy Plover. Photo: Greg Lavaty

The Utah Division of Water Quality is poised to make a decision on selenium limits that may be allowed to be discharged into the lake, but a prominent U.S. Fish and Wildlife Service expert, Joe Skorupa, has stated that the standards will not be protective of all bird species that feed and breed in and around the region. Skorupa has recommended a standard of five parts per million (ppm) in bird eggs, about twice as restrictive as the standard recommended by a committee that is made up of representatives of industry, environmental groups, governmental agencies, and others.

American Bird Conservancy believes that setting a standard that will protect all bird species is warranted, and that the data indicate that a five ppm standard should be adopted. No schedule has been proposed for a mercury standard, which may be more complicated than a selenium standard, because selenium and mercury interact, and the effects on toxicity are not completely understood.