The population of the federally protected species grew by 14 percent over the past year, from 574 to 654, the U.S. Fish and Wildlife Service reported. But the finger-length fish with a black spot on its tail still has a long way to go before it will be considered safe from extinction.
"The fish are responding to the restoration efforts that have been done," Amy LaVoie, manager of the 117-acre Moapa National Wildlife Refuge told the Las Vegas Review-Journal. "We knew in general if we improved the habitat, the fish would respond."
The count last month continues an upward trend for the dace, after an unexplained die-off about five years ago. The population also seems to be spreading after a July 2010 wildfire seemed to concentrate the fish in one small stretch of stream on the refuge.
"They're in more reaches now than they were before the fire," Fish and Wildlife Service spokesman Dan Balduini said. "They've spread out more, and that makes them a little tougher to count."
Biologists swimming with goggles in the shallow headwaters of the Muddy River count the fish twice a year. The February counts are lower than the August ones because the dace does a lot of its spawning in the spring and food is more plentiful. Both sets of numbers have been going up since 2008.
The dace has been under federal protection for more than 40 years. It is expected to remain on the endangered species list until at least 75 percent of its historical habitat has been restored and its population holds steady at 6,000 adult fish.
A single valley in northern Clark County is the only place in the world where the Moapa dace is found. Its entire habitat is confined to the refuge, some adjacent private land and the Warm Springs Natural Area, a 1,218-acre tract the Southern Nevada Water Authority bought for $69 million in 2007.
The wholesale water supplier for the Las Vegas Valley agreed to help protect the dace under a 2006 federal agreement that cleared the authority to pump groundwater from nearby Coyote Springs.
Recent preservation work has drawn criticism from neighboring residents, especially when it came to cutting down hundreds of palm trees that give the area the feel of a desert oasis.
A work crew hired by the water authority to clear trees and brush accidentally sparked the 2010 summer wildfire that spread onto neighboring property. Several homes and other structures burned, including much of the Warm Springs Ranch, a private, 72-acre recreational area for members of the Mormon church. Damage was estimated at $2.5 million.
Authority officials have said they are done clear-cutting palm trees and are developing some trails and information kiosks so they can start opening parts of the Warm Springs Natural Area to the public.
At the Moapa National Wildlife Refuge across the road, workers finished installing interpretive signs and building new trails.
LaVoie said refuge staff members plan to hold an open house for Moapa Valley residents this month. The refuge is open to the public from sunrise to sunset on Fridays, Saturdays and Sundays through the end of May, when it will close for the summer.