USA: Nevada: Ash Meadows National Wildlife Refuge Desert Spring Restoration

Project Stage:
Implementation

Start Date:
1997-04-01

End Date:
2007-12-21

Primary Causes of Degradation

Degradation Description

Historical land use has altered the landscape and habitat of these springs. Agricultural activities, road-building, and earth removal for water diversions and dams have resulted in large-scale disturbance to surface soil and vegetation, as well as large-scale hydrologic changes. In addition, this disturbance has allowed the proliferation of invasive species. Of particular concern for the native fishes has been the introduction of non-native fish species such as mosquitofish, and sailfin molly, which have preyed on native fish larvae and/or competed for habitat. Non-native crayfish have also preyed on native fish larvae. Non-native plant species, such as tamarisk, also compete with native species for the scarce water resources within the Refuge, and have drastically altered the habitat.

Reference Ecosystem Description

Ash Meadows NWR supports at least 24 endemic plants and animals – the highest density of endemic species in the United States. Ash Meadows NWR is inhabited by six endangered and eight threatened species, the majority of which are found nowhere else in the world. In addition, the refuge supports numerous organisms that are characteristic of desert riparian habitats of the American southwest. Therefore, it is of extraordinary value to biodiversity and to the preservation of unique habitats.

Listed species in the refuge include an endangered plant, the Amargosa niterwort (Nitrophila mohavensis); six threatened plants, the spring-loving centaury (Centaurium namophilum), Ash Meadows ivesia (Ivesia eremica), Ash Meadows blazing star (Mentzelia leucophylla), Ash Meadows milkvetch (Astragalus phoenix), Ash Meadows sunray (Enceliopsis nudicaulis var. corrugata), and Ash Meadows gumplant (Grindelia fraxino-pratensis); a threatened invertebrate, the Ash Meadows naucorid; and four endangered fishes, the Devils Hole pupfish, Warm Springs pupfish (Cyprinodon nevadensis pectoralis), Ash Meadows Amargosa
pupfish (C. n. mionectes), and Ash Meadows speckled dace.

Project Goals

Ash Meadows NWR has a recovery goal of ecosystem and species restoration. Recovery criteria for meeting this goal involve restoration of the natural distribution of habitats, as well as self-sustaining populations of all species throughout the Refuge. In 1990, a recovery plan was written for Ash Meadows NWR, which listed the recovery needs for 12 listed species. It also identified tasks necessary to down-list/de-list these species. Although emphasis was placed on endangered species, the plan recognized the necessity for recovery of the ecosystem processes on which these species depend. The Recovery Plan identified the following objectives in the service of down-listing/de-listing endangered fish:

1. Eradicate all non-native species from essential habitat.
2. Protect the Ash Meadows aquifer.
3. Reestablish flow to historic channels.
4. Protect essential habitat from human disturbances.
5. Restore historic fish distributions.
6. Create and maintain refugial populations of the Devil’s Hole pupfish.
7. Maintain populations of Devil’s Hole pupfish at a minimum of 300 in winter and 700 in summer.

Monitoring

The project does not have a monitoring plan.

Stakeholders

Lead agency: U.S. Fish and Wildlife Service
Project partners: Otis Bay Ecological Consultants, Nevada Conservation Corps, Exotic Plant Management Team (EPMT) from Lake Mead National Recreation Area

Description of Project Activities:
To date, restoration work has been completed on Kings Spring and Jackrabbit Spring.  As funding allows, more restoration work is planned on other springs on the Refuge. Kings Spring Restoration actions at Kings Spring included reconstruction of the spring pool and outflow channel.  Local rock was used to create rock shelves in order to create breeding and foraging habitat for the Ash Meadows pupfish (Cyprinidon nevadensis mionectes). Reshaping Kings Pool required a reduction to the size of its original perimeter, an increase in the slope of its bank, and the armoring of the bank with slabs of caliche rock, in order to limit re-establishment of cattail. The Kings Spring outflow channel was designed and constructed to accommodate the discharge from Kings Spring as well as the occasional flooding due to overland flow from an adjoining alluvial fan.  The restoration of the connection of the alluvial fan to the outflow channel was critical for the delivery of coarse sediment which is the preferred substrate for the endangered Ash Meadows naucorid (Ambrysus amargosus).  In addition, the occasional channel scour associated with flooding from the alluvial fan is critical for the maintenance and creation of spring channel habitat at Kings Spring.  Three ephemeral washes, which were historically part of the Kings Spring watershed, were reconnected to the Kings Spring channel by removing the berm that blocked their access and regrading the washes to their original slope. A mesquite-ash dominated system was re-established by placing excavated topsoil, then transplanting and seeding native vegetation along the stream banks and floodplain. Nursery-grown trees and shrubs were also planted in the floodplain. Jackrabbit Spring The first 1,500 feet of channel downstream from the spring source was semi-natural as historical channelization for irrigation was abandoned and the channel began to adjust toward sinuosity after maintenance of the ditch ceased.  The channel had a low width-to-depth ratio with a slope which allowed higher-velocity channel flow - conditions favorable to native Ash Meadow speckled dace. Given this, the reach was used as a general reference for the channel reconstruction design downstream.   The channel reconstruction took place on 1,500 additional feet of stream channel, beginning approximately 1,500 feet downstream from the spring source.  "¨"¨Channel reconstruction began with draining of agricultural impoundments, removal of berms, filling of the impounded areas with coarse material, and recontouring the site to its natural topography "” the approximate slope of the upstream reference reach.  Design objectives for the channel reconstruction were to create a narrow (18- to 24-inch-wide), swift (1-1.5 feet per second), and deep (6- to 18-inch) channel - dimensions similar to other channels in which Ash Meadows speckled dace had thrived.  The higher velocity was also important in preventing the channel from filling in with vegetation.  Confining the channel was important in preventing sheet-flow, maintaining the thermal load of the stream, and minimizing the development of cattail marsh.  Coarse sediment has been added to the excavated channel, and rock and log structures were installed to create riffles and pools, allowing for drift-feeding stations for the Ash Meadows speckled dace.  "¨"¨Restoration efforts also included mechanical removal of salt cedar, revegetation within the outflow channel corridor, and culvert replacement.  The previous pipe culvert was approximately 2,500 feet downstream from the reconstructed channel.  It was undersized and had a 12-inch drop at the outlet, which created a barrier to upstream movement of speckled dace. The new concrete box culvert was installed to improve fish passage and to reduce the amount of cattail marsh created by the backwater effect of the former culvert. "¨"¨Vegetation restoration was completed on 1,120 acres within the burned area around Jackrabbit Spring Creek.  It included control of non-native invasive weeds using herbicide and mechanical treatments, and planting of native species. Noxious weeds, including Russian knapweed, salt cedar, Maltese star-thistle, Russian olive and hoary cress were chemically treated. In April 2006, mechanical removal of invasive salt cedar and chemical treatment of five-hook bassia and Russian knapweed took place. Removal of salt cedar was done by SWEAT. "¨ Native grasses/forbs, shrubs and trees were planted within the perimeter of the burned area during September through October 16, 2006. A total of 250 acres were planted and seeded.  Plants were propagated from native seeds.  Cuttings were collected from the Refuge during Fall 2005 and Spring 2006, and grown by the Community College of Southern Nevada in Las Vegas. Seed which was not used for plant propagation was spread in disturbed areas to enhance natural recovery of native plants. Velvet ash, willows, mesquite, bunch grass, and salt grass represented the bulk of the species planted.

Ecological Outcomes Achieved

Eliminate existing threats to the ecosystem:
Proactive restoration efforts in Kings Spring drainage of the Ash Meadows NWR has promoted control of non-native fish populations and a swift return of native fish populations to desirable levels. There was a significant shift in species composition of the channel. Prior to restoration, native fish were only 23 percent of the total fish population. Five years following restoration, native fish were 91 percent of the total population. This percentage is expected to increase once the marshy habitat downstream of the project area is restored. In the Jackrabbit Springs drainage, initial observations show that Ash Meadows speckled dace have moved downstream from the natural channel and are using the reconstructed channel. It is too soon to evaluate the progress and results of weed management and revegetation efforts.

Factors limiting recovery of the ecosystem:
Early observations of the reconstructed channel in Jackrabbit Spring conclude that the channel has widened and become more shallow. In the majority of the stream, the banks have sloughed into the channel due to either insufficient compaction or other characteristics of the soil used. Additional work will be done this winter to narrow and deepen the channel, including adding rocks, logs, and willow wattles for bank stabilization. Juniper and mesquite fenceposts are also being collected from the NWR and used for bank stabilization.

Socio-Economic & Community Outcomes Achieved

Key Lessons Learned

Research provided critical understanding of habitat preferences of native versus non-native fish. Understanding these habitat preferences within the refuge allowed a sound restoration design that promoted native fish over non-native fish. The sailfin molly and mosquitofish, typical invaders of thermal springs of the American Southwest, prefer lentic conditions. The restored channel configuration of Kings Spring drainage included maintaining the spring’s elevated temperature and establishing a conversion of Kings Spring Pool outflow from marsh to warm water lotic habitat.

Long-Term Management

U.S. Fish and Wildlife Service monitoring of Ash Meadows native fish have taken place since 1989. The monitoring protocol has typically involved a single annual sampling run to limit research impacts on fish health, using minnow traps at major springs. Mark-recapture estimation has been repeatedly conducted and has been used to estimate the population size of each target species. In addition, notes on the numbers of non-native fish, crayfish, and other species have been recorded.

Restoring native vegetation at the Kings Spring site and across the Refuge has been a challenge. Non-native species continue to be a concern. A revegetation plan is being written for Kings Spring and additional funding will be sought.

Sources and Amounts of Funding

65,000 (Kings Spring Drainage) USD Restoration work on the outflow channel of Jackrabbit Spring was performed with funds from the Southern Nevada Public Lands Management Act under contract with Otis Bay Ecological Consultants (http://www.otisbay.com).Â

To keep costs down, much of the restoration work done on Ash Meadows NWR is by volunteers.

Other Resources

Sharon McKelvey
Refuge Manager, U.S. Fish and Wildlife Service
Email: Sharon_McKelvey@fws.gov

Shawn Goodchild, Fish and Wildlife Biologist
U.S. Fish and Wildlife Service, Southern Nevada Field Office
Email: Shawn_Goodchild@fws.gov

Publications:
Peer reviewed:
G. Gary Scoppettone, Peter H. Rissler, Chad Gourley, and Cynthia Martinez. 2005. Habitat Restoration as a Means of Controlling Non-Native Fish in a Mojave Desert Oasis. Restoration Ecology: 13(2): 247-256.

Not peer reviewed:
http://wildfish.montana.edu/Cases/browse_details.asp?ProjectID=82
http://www.otisbay.com/projects/nevada/ashmeadows/ashmeadows.html

Primary Contact

Organizational Contact