BISHOP, Calif.— The Center for Biological Diversity petitioned the U.S. Fish and Wildlife Service today to protect three populations of speckled dace in the Death Valley region under the Endangered Species Act. These small, minnow-like fish live in freshwater streams and springs in the desert and dry environments of Amargosa Canyon, Long Valley and Owens Valley, California.
“The fragile desert rivers and springs that support dace are also important to many other wildlife species and people, so federal protection is crucial,” said Jeff Miller, a senior conservation advocate at the Center. “We need to rein in excessive groundwater pumping and make sure these unique fish populations don’t wink out forever. We can’t afford to lose any more of California’s unique freshwater fish species.”
The stream habitats of the Amargosa Canyon speckled dace, located in the Amargosa River and its tributaries south of Tecopa, are under imminent threat of dewatering due to excessive groundwater extraction.
The last population of Long Valley speckled dace in the wild, a hot spring near Mammoth, may no longer exist, leaving but one population in a managed refuge. And Owens speckled dace no longer occur in most of the small streams and springs they used to inhabit in the Owens Valley. They are now only found in irrigation ditches and one natural habitat near Bishop.
Background
Recent genetic analyses reveal that speckled dace populations in Amargosa Canyon and Owens Valley are the same subspecies as the Ash Meadows speckled dace (Rhinichthys osculus nevadensis) in western Nevada, which has been listed as a federally endangered species since 1984. The Long Valley speckled dace has been identified by genetic analysis as a separate subspecies, which scientists have yet to formally describe.
Amargosa Canyon speckled dace are confined to the Amargosa Canyon reach of the Amargosa River and its tributary Willow Creek. Their range has been constricted by excessive groundwater extraction for agriculture, rural residential development, and urbanization, which reduces surface flow in the Amargosa River.
Long Valley speckled dace formerly occurred in warm springs throughout the isolated Long Valley volcanic caldera, just east of Mammoth Lakes. Geothermal energy development in Long Valley subsequently altered the hydrology of hot springs. Dace have been eliminated from Hot Creek, Little Alkali Lake, and various isolated springs and ponds in Long Valley. The sole remaining population in Whitmore Hot Springs was thought to be stable in 2009, but 2019 surveys failed to locate any of the fish.
Owens speckled dace historically occupied most small streams and springs in the Owens Valley, but groundwater extraction eliminated many spring habitats. Speckled dace persist in three locations in northern Owens Valley, including irrigation ditches in Round Valley and near Bishop, but the only native habitats they still occupy are several isolated springs in Fish Slough. Further groundwater depletion threatens the springs at Fish Slough.
Other threats to these speckled dace include habitat alteration for agricultural use, river channelization, vegetation clearing, livestock grazing, off-road vehicles, and recreational development of hot spring water sources. Introduced fish, crayfish and bullfrogs prey upon on and compete with speckled dace, and invasive plants such as saltcedar are severely altering spring and riparian habitats along the Amargosa River.
Changes in precipitation, snow and runoff in the Death Valley region due to climate change will result in reduced stream flows and inadequate aquifer recharge to sustain many of the ephemeral streams and springs which speckled dace rely on.
Last month the Center petitioned to protect the related Santa Ana speckled dace, which inhabits the Santa Ana, San Jacinto, San Gabriel, and Los Angeles river systems of Southern California.
More than 80% of California’s native freshwater fishes are in decline, an indication of the degrading quality and quantity of freshwater habitats throughout the state. Thirty-three California freshwater fish species are formally listed as threatened or endangered, and seven of the state’s native fish species have already gone extinct.
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June 08, 2020 at 11:05PM
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Endangered Status Sought for Death Valley Region Fish - Center for Biological Diversity
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