Enhancing Habitat for Rare Endemic Fish on the Amargosa River
The Amargosa River south of the town of Tecopa is a green island oasis in the middle of one of the driest and hottest regions in the Western United States. Summer temperatures often rise above 120 degrees and rain seldom reaches this part of the Mojave Desert, but the Amargosa River, fed by deep carbonate springs, peaks above the parched desert landscape year round. This isolated island of green provides a home to many sensitive plant and wildlife species.
Two of these species, the endemic Amargosa Pupfish and Amargosa Speckled Dace, occur nowhere else on earth. In recognition of its uniqueness, this part of the river was designated as an Area of Critical Environmental Concern (ACEC) by the Bureau of Land Management in 2002 and designated by congress as a Wild and Scenic River (WSR) in 2009.
Based on fish surveys conducted this last fall, these two species appear to be doing fairly well, however, the fish face several challenges to their continued existence. River flows have decreased over the years due to ground water pumping in California and Nevada, the flow pattern has been altered by development, and habitat has been degraded by the introduction of non-native predatory animal species such as the red-swamp crayfish, bullfrogs, and mosquito fish. Climate change may also play a factor with water availability for the species.
One of the major threats to fish habitat has been the introduction of the non-native salt cedar which removes water from the system through transpiration and shades the river, decreasing food resources within the waterway
In order to address the salt cedar issue, the Barstow Field Office of the Bureau of Land Management launched a salt cedar removal program within the range of the Amargosa Pupfish and Amargosa Speckled Dace two years ago. Since the program began, over 75 acres have been treated with plans to treat another 100 acres over the next two years. Funding, labor and ongoing monitoring for this habitat restoration work was completed with a partnership between the Desert Fish Habitat Partnership and the BLM Apple Valley Fire Department.
The salt cedar treatment is also improving the habitat for other sensitive species including the endemic Amargosa Vole and federally listed Least Bell’s Vireo. Salt cedar treatment is an integral part of the management of the Amargosa River system and is vital to the health of the regional ecosystem. The BLM looks forward to continuing to work with our partners to improve the integrity of the Amargosa River.
-- Chris Otahal, Wildlife Biologist, BLM Barstow Field Office, California (March 2015)