 |
| Moapa Valley National Wildlife Refuge |
Clark, Nevada |
Primary Project Type: Instream Restoration
Secondary Type: Riparian Restoration |
 |
| |
The Warm Springs area of Moapa Valley is an oasis within the Mohave Desert with ... |
|
|
 |
Primary Problem: Channel Alteration, Loss of Fish Habitat
Secondary Problem: Channel Alteration |
| Main Restoration Action(s): Channel reconstruction, Habitat enhancement |
| Native Fish Focus: Moapa dace |
Is this project part of a watershed scale restoration? No
|
| Project Dates: 2002 to Ongoing |
| |
Initial Monitoring:
Restoration Implementation:
Follow-up Monitoring: |
|
Lead Agency:
U.S. Fish and Wildlife Service
|
| Project Partners: |
|
| Project Location:
The Moapa Valley National Wildlife Refuge (NWR) is located in the Warm Springs area of the upper Moapa Valley. It occupies 117 acres in northeastern Clark County, approximately 60 miles north of Las Vegas, Nevada, and 9 miles west of the town of Moapa.
|
| |
Project Description:
The Warm Springs area of Moapa Valley is an oasis within the Mohave Desert with numerous thermal springs that empty into the Muddy River. Several of these springs surface at various places on the Moapa Valley Refuge and combine to form three major streams – Pedersen stream, which has an average discharge of 3.6 cubic feet per second (cfs), the Plummer stream, which has an average discharge of 3.1 cfs, and the Apcar stream, with an average discharge of 2.9 cfs. At the point of discharge, the springs have an average annual water temperature of 90 degrees Fahrenheit. Once found throughout the headwaters of the Muddy River system, the Warm Springs system is the last remaining habitat in the world for the endangered Moapa dace (Moapa coriacea), a fish dependent on warm-spring habitat for reproduction.
In the late 1800s, the Moapa Valley became populated by Mormon settlers, and the streams were diverted and channelized for domestic and agricultural uses as development increased. Despite the development, the Moapa dace populations continued to thrive through the early 1900s. In 1963, the population rapidly declined after the introduction of the shortfin mollie, a non-native fish. By 1967, the Moapa dace was federally listed as endangered. Prior to listing, both the Pedersen and Plummer springhead areas were developed and operated as a resort in what is now the refuge, with snack bars and recreational vehicle hook-ups. The springs and outflow channels were chlorinated and developed into concrete swimming pools, spas and bath houses. By 1979, no Moapa dace were left on the site, and previous attempts to transplant this species to other habitats failed. In 1979, the first parcel of land was purchased by the U.S. Fish and Wildlife Service to establish a refuge with the purpose of protection and recovery of the endangered Moapa dace. |
| Project Goals: The primary management objectives of the refuge are to restore the Plummer, Pedersen and Apcar channels to as near a natural condition as possible and to optimize available stream habitat for recovery and delisting of Moapa dace. |
| Project Methods:
Habitat restoration restoration on the Moapa Valley Refuge began in 2002 on the Pedersen unit, resuming in January 2006 on the Plummer unit, and has consisted of the removal of the former swimming pool, other structures and, non-native vegetation, construction of the stream outflow channel, and construction of an aquatic habitat viewing chamber within the Plummer spring complex. The viewing chamber was constructed in order to increase public awareness of the rare species that occur within the refuge and to improve habitat for the Moapa dace and other native aquatic species. The main components of the fish viewing facility are the windows, which show the stream channel and aquatic habitat in profile view, and trails that lead the public to and away from the viewing chamber. Trails guide visitors over and along the outflow channels, past the viewing chamber, and through the surrounding rolling terrain. Restoration efforts have also included removal of a dominant vegetative stand of non-native palm trees (Washingtonia filifera and Phoenix dactylifera), which are a fire hazard and constrict stream and spring outfow channels encroaching upon Moapa dace spawning, nursery, and adult foraging habitats.
For more information on project methods, click here.
|
 |
| |
In addition to early-settler stream channelization for domestic and agricultural... |
|
|
|
|
|
|
| Monitoring Data and Collection
Methods: In February 2007, the Southern Nevada Water Authority, Nevada Department of Wildlife, and the U.S. Fish and Wildlife Service, Ecological Services conducted their annual snorkel surveys for the fishes of the Muddy River system, primarily the Moapa dace. The surveys included springs on the Moapa Valley NWR. A total of 1,172 Moapa dace were counted during the surveys — 395 in the Peterson stream and 170 in the Plummer stream of the Moapa Valley NWR. Although Moapa dace were found downstream from the refuge in the Apcar stream, no Moapa dace were found in the Apcar stream on the refuge. Shortfin mollies and gambusia were in large numbers throughout the Muddy River system, including in streams on the Moapa Valley refuge.
|
Was this project effective
and how was this determined? Efforts are continuing on the Moapa Valley National Wildlife Refuge to create and improve habitat in both the Pedersen and Plummer stream systems for all life stages of Moapa dace. Restoration efforts on the Plummer outflow channel are largely complete, and Moapa dace have already been observed inhabiting the new arrangement of pool, riffle, and run habitats. Non-native mosquitofish (Gambusia affinis) and shortfin mollies (Poecilia mexicana) do inhabit the new spring pools and channel; however, the newly designed channel promotes native fish habitat over non-native fish. The refuge manager is seeking additional options to manage these non-native fishes. At this time, Moapa dace are extirpated from the upper Apgar unit. A recent purchase of 45 acres on the Apcar unit has provided an opportunity restore Moapa dace populations back to this spring system, beginning with removal of a dense stand of non-native palm trees.
Aquatic plants such as Chara and other algae, spike rush (Eleocharis spp.), water nymph (Najas spp.), watercress (Nasturtium spp.), and pondweed (Potamogeton spp.) are now abundant in the spring pools and channels. Several palms around the Plummer unit bear the scars of the 1994 wildfire. However, with on-going removal of non-native species, salt cedar (Tamarix spp.), and young palm trees, a ground cover of salt grass (Distichlis spicata) has established, and native riparian species have begun to return — including ash trees (Fraxinus velutina), honey mesquite (Prosopis glandulosa), and screw bean mesquite (P. pubescens).
The Moapa Valley NWR is currently closed to the public as public use facilities are constructed and the newly-constructed fragile dace habitat is given time to stabilize. Other opportunities exist for habitat management and barrier construction to protect the Moapa dace population — most of those opportunities exist on private land, which is adjacent to the refuge. The refuge manager is pursuing discussions with the land owners for cooperation in protecting this rare species.
|
 |
| |
The newly constructed outflow channel.... |
|
|
|
|
|
|
| Confounding Effects/Additional
Information: |
| Project
Specs (all specs are estimates): |
| |
Overall Estimated Cost:
$75,000 for stream restoration. $1.5 million with all the public use facilities being constructed.
|
|
| For more information on this project
contact: |
| |
Amy Sprunger, Refuge Manager, U.S. Fish and Wildlife Service, Email: Amy_Sprunger@fws.gov
|
| This information
was collected by: Kristin Keith |
| Project last updated on: 5/1/2007 |
|
 |
|
