Endangered Moapa dace experience healthy population jump
A recent survey shows the Moapa dace
population is on the rise.
According to a recent survey, the population of Moapa dace, a tiny, endangered fish found only in the headwaters of the Muddy River, has nearly doubled.
The February 2013 survey was conducted by the U.S. Fish and Wildlife Service (USFWS) in cooperation with SNWA and Nevada Department of Wildlife (NDOW) and turned up 1,226 Moapa dace. That amount was almost twice the 654 fish recorded the prior year. In February 2008, the population reached an all-time low since surveys began in 1994, with only 459 fish found.
Biologists from SNWA, NDOW and USFWS conducted the snorkel survey of 17 stream reaches located on the Warm Springs Natural Area, Moapa Valley National Wildlife Refuge and private land. The system of springs that feed the Muddy River flows to Lake Mead.
Listed in 1967 under the Endangered Species Preservation Act of 1966, Moapa dace are endemic to the warm waters of the upper Muddy River. They live nowhere else on earth. These fish begin their lives in the area’s warm spring outflows and move to cooler water downstream as adults; adult Moapa dace return to the warm springs to reproduce.
The SNWA, USFWS, and NDOW survey the Warm Springs area twice each year, in February and August. While the February count represents only a slight increase from the 1,181 fish counted last August, Moapa dace populations tend to vary thorough the year and traditionally are higher in summer months. Therefore, the increase in fish this February was unexpected and welcome.
The dramatic sustained population increase demonstrates the value of habitat restoration to sensitive species such as the dace, said Zane Marshall, the SNWA’s Director of Water and Environmental Resources.
"The winter survey’s findings illustrate the spirit of interagency cooperation and stewardship, and show how public entities can work together to achieve positive results for our natural environment,” Marshall said.
A USFWS recovery plan for the Moapa dace set delisting goals at 6,000 fish in five spring systems for five consecutive years, restoration of 75 percent of historic habitat, and effective control of non-native, invasive fish.
To achieve those goals the SNWA, acting as steward for the Warm Springs Natural Area, works with its partners to install non-native fish barriers, eradicate exotic species, restore natural stream flow dynamics and riparian vegetation, and improve connectivity between springs and streams.
The SNWA acquired the 1,220-acre Warm Springs Natural Area, about 60 miles northeast of Las Vegas, in September 2007. The SNWA recognizes the Moapa dace as a key species in its management of water resources in the Muddy River and Coyote Spring Valley due to the fish’s ties to the deep carbonate aquifer and its limited distribution.
