An excellent overview of the ecological setting, waterbird biology and habitat management of the Great Salt Lake and the surrounding wetlands is provided in "Avian Ecology of Great Salt Lake" by Tom Aldrich and Don Paul in Great Salt Lake: An Overview of Change. (Edited by J. Wallace Gwynn, Ph.D., Special Publication of the Utah Department of Natural Resources, 2002.) The following description of Gunnison Bay is from this article: Gunnison Bay is the second largest expanse of open water. The north arm is bounded by salt playas and the Locomotive Springs WMA on the north; by the Promontory Mountains on the east; by the Hogup Mountains on the west; and by the Southern Pacific Railroad causeway on the south. It is also the most remote and xeric region of the lake and, perhaps more importantly, the most saline. Salinity ranges between 240 and 280 ppt. Gilbert Bay is presently a hypersaline system dominated by halophytic bacteria; it is too salty for brine shrimp and brine flies to persist. Currently, it appears to be a salt trap with possibly 3 to 5 vertical feet (1 to 1.5 meters) of salt precipitate on the lake floor. It possesses several minor wetlands that function to support small populations of unique birds. Gunnison Island has provided a nesting habitat for an impressive number of American white pelicans (Pelecanus erythrorhynchos) and California gulls (Larus californicus) before, and since settlement of the area by Anglo-Americans. For birds choosing to nest on this remote island, the tradeoff is a predator-free nesting environment for marathon flights to forage and gather food for young.

Ornithological Summary

Gunnison Bay is recognized as a Globally Important Bird Area.

This status is based on three species. The American White Pelican breeds at Gunnison Island with total numbers that can exceed 20,000, or over 11% of the North American population. California Gulls breed at Gunnison Island with numbers that can exceed 23,000 or over 3.7% of the estimated North American population. The Long-billed Curlew is a Global Species of Conservation concern. The global criteria has been set at 30 breeding individuals and counts at Locomotive Springs and Salt Wells Flat show counts of over 60 breeding individuals. Partners in Flight priority species that use Locomotive Springs and Salt Wells are American Avocets (with counts over 400) and Black-necked Stilts (with counts over 180). Also these two areas are used by Snowy Plover (with counts over 370), which is listed as a Utah Wildlife Action Plan priority species,

Three survey sites within Gunnison Bay also met IBA qualifications based on avian congregation numbers. Specifically, the site qualified based on significant numbers of wading birds including the American White Pelicans detailed above, 165 White-faced Ibis at Locomotive Springs and Salt Wells, significant numbers of California Gulls at Gunnison Island plus counts of over 4,000 California Gulls at Locomotive Springs and Salt Wells and significant counts of shorebirds due to breeding numbers of American Avocets, Black-necked Stilts, Snowy Plovers and Wilson?s Phalaropes.

Conservation Issues

Although Gunnison Island is isolated, there are major concerns about maintaining this isolation so American White Pelicans will continue to use the area. Pelicans are very sensitive to disturbances during the nesting season. The primary threats come from proposals for landfills, energy development, and mineral extraction. There is a major concern over adequate water for Locomotive Springs, due to the drawing down of the water table for agricultural uses in the area. Another on-going concern is the restricted water exchange with the rest of the Great Salt Lake due to the railroad causeway, thus affecting water chemistry.

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