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Show fluctuations. These areas are critical to Snowy plovers for nesting and provide foraging and staging areas for numerous shorebirds, including tens of thousands of Avocets and Stilts. The associated shoreline supports a robust population of brine flies which is a significant avian food source. The transitory nature of this habitat type introduces a constant dynamic state so that emergent vegetative stands are constantly shifting between early and late serai stages as the water levels advance and recede. A rich mosaic pattern of habitat types is the result. Some examples include Farmington Bay, Howard Slough and the areas west of existing WMAs and TNC's Layton Wetlands Preserve. There are numerous ephemeral pools that are associated with the mudflats and playas. They are resultant of slight changes in topography and precipitation, overland flow ( runoff), wind tides from the main lake and receding lake levels. Small pools create critical habitats for waterfowl and shorebirds and create unique places for food production of invertebrates and vegetation species. Salinity Variations Salinity varies around the main body of the lake due to geographic location, geology and the presence of human- made structures. A variety of plants and invertebrates are dependent on these differing saline habitats. Each species has an optimum range of preferred salinity levels, and this wide spectrum of salinities provides unique and critical habitat for wildlife. Brine shrimp play a significant role in the GSL ecosystems and, along with brine flies, are the keystone species supporting many of the water and shorebird species that frequent the lake. A primary reason for the hemispherically important bird numbers at GSL is the lake's capacity to produce millions of pounds of easily foraged protein at the appropriate times for staging and molting migratory birds. Generally, the north arm ( Gunnison Bay) is extremely saline and only supports brine shrimp when the lake is at very high elevations. The west and south shores are moderately saline, and support brine shrimp at high to average lake elevations. The northeast, east and southeast sides of the lake are less saline and support brine shrimp and other invertebrates during average and lower lake elevation years. These open lake and littoral zones are exceptionally important to phalaropes, Franklin and California gulls and Eared grebes. The east shore of the lake has many productive habitats due to the freshwater deltas of the Jordan, Weber and Bear Rivers, and numerous smaller Wasatch Front streams. The water from all these drainages has been totally or partially diverted through natural or managed wetlands adjacent to the lake. The historic Jordan and the Weber River Deltas have been abandoned and receive little or no natural flow. These are very productive areas for waterfowl, colonial nesters and many shorebirds, including Dowitchers, Yellowlegs, Godwits, Avocets and Stilts. Managed Wetlands Managed wetlands have created unique habitats with dikes, levies, headgate systems and diversion structures. These systems enhance the opportunities for active management by changing water depths, temperature and water dispersion patterns and by controlling nutrient flows over time. These managed wetland areas accommodate seasonal use and the needs of migrating and breeding water birds. 80 |