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Show Open Water or Pelagic The main area of the lake provides this habitat type. When the surface water is relatively calm, huge numbers of waterfowl raft in these areas. Few disturbances allow birds to rest without molestation. These areas also provide important foraging opportunities. Brine flies are found on floating bits of vegetation, shrimp, and cysts floating on the lake surface. Huge flocks of Goldeneyes and Shovelers have been observed on the lake, presumably feeding on these resources, however research needs to document this information. During the winter there are other species of maritime waterfowl that are occasionally observed on these expansive open waters. These species include Oldsquaws and Scoters. Shorebirds GSL has one of the largest shorebird concentrations in the world. Over 35 species of shorebirds are found in the Western Hemisphere ( Sorensen, 1997). Many of these visit GSL each year and commonly include American avocet, Black- necked stilt and Killdeer. Many of these birds undertake extraordinary migrations with some birds traveling up to 2- 3,000 miles. Over 50 percent of the world population of Wilson's phalaropes ( 500,000), the largest staging population in the world, depends on GSL. The largest population of American avocets ( 250,000) and Black- necked stilts ( 65,000) in the Pacific flyway, and over 10 percent of all Red- necked phalaropes ( 280,000) stop over on GSL. The lake also hosts the world's largest assemblage of Snowy plovers ( 10,000), and the only staging area for Marbled godwits ( 30,000) in the interior of the United States. Observations of over 30,000 Long- billed dowitchers have been made on a single occasion. The GSLEP is cooperating in the development of a national shorebird management plan. When completed, the shorebird plan will be the basis for future shorebird management decisions involving the lake. Habitat Relationships The most significant aspect of the GSL ecosystems is the great diversity of habitats created from the integration or close association of fresh and salt water systems which create a fluctuating " mosaic" of land forms, vegetative cover, water and salinity. Several habitat types, natural and human- made, are described below to illustrate the importance of each micro- habitat. Management and conservation efforts must consider each habitat type and the species that frequent these areas. Estuaries Fresh and salt water interfaces are created where flowing freshwater enters directly into the lake such as the outflows of several small streams along the east shore. These areas provide important foraging areas for breeding, brooding, and staging. These areas also stay ice- free in winter and provide habitat for waterfowl. Playas/ Ephemeral Pools Salt playas, mudflats and other lake interfaces occur at numerous locations throughout the extremely shallow, low gradient GSL Basin. These environments shift seasonally and with lake level 79 |