Relict Dace Restoration Project

Relict Dace in hand

The Relict Dace is the only fish species native to Ruby Lake National Wildlife Refuge where its population has been dramatically reduced.  Today, Relict Dace only remain in a few isolated Refuge springs.  The mission of the National Wildlife Refuge System is to conserve, manage, and restore fish, wildlife, and plant resources and their habitats, therefore, a project to protect and expand Relict Dace populations has been developed.  The Relict Dace Restoration Project is a multi-phase project that involves state, federal, private, and academic partners.  Together, this partnership has worked to locate and inventory remaining dace populations and identify/restore habitat that can be used for future translocations in an effort to bolster populations of this small fish.

The earliest documented fish survey of Ruby Valley, conducted in the 1940s, indicated that the Relict Dace (Relictus solitarius) was the only species present.  It was also discovered that Relict Dace existed only in freshwater marshes, streams, and springs in northeastern Nevada.  These rare fish average two-four inches in length and rely on clean, cool water and healthy aquatic vegetation for cover and spawning.

It was also in the 1940s when Largemouth Bass were stocked at Ruby Lake National Wildlife Refuge for sportfishing.  Rainbow Trout, Brown Trout, and Brook Trout were later stocked to provide additional fishing opportunities.  Largemouth Bass populations soared in the marsh and the area became popular and well known for excellent fishing.  Relict Dace were easy prey for bass and trout and populations declined markedly.  This prompted the introduction of the non-native Speckled Dace to replace the vanishing Relict Dace in providing forage for the larger sportfish.

Concerns over the fate of the Relict Dace resulted in the development of a multi-phase, multi-partner restoration project.  Refuge staff, in partnership with the Nevada Department of Wildlife (NDOW), secured grant funding for the project through the Southern Nevada Public Lands Management Act.  Otis Bay Ecological Consultants (OBEC) was hired in 2011 to implement the project utilizing their extensive experience with fish and wildlife habitat restoration in Nevada.

Because interbreeding between Relict and Speckled Dace was suspected, the first step was to determine if any genetically pure Relict Dace persisted on the Refuge.  A genetic analysis of tissue samples from dace located in several springs and ponds on the Refuge was conducted at Brigham Young University in Utah.  The results showed that three springs did in fact still hold genetically pure Relict Dace.

Newly constructed Relict Dace pondOBEC, NDOW, and Refuge staff then proceeded to identify which springhead pools and ponds were still suitable for Relict Dace.   A suitable translocation site was one that was, or could be, isolated from other waterbodies containing sportfish and provided suitable habitat.  The team also determined which sites required habitat restoration and located several new sites where suitable habitat could be created.  Several ponds required not only the removal of Speckled Dace, but also the introduced Signal Crayfish, an invasive species known to threaten dace populations elsewhere.

In September and October 2011, OBEC constructed five new ponds and modified five existing ponds for the Relict Dace.  Modifications included expansion and re-grading of ponds and the installation of downstream fish barriers.  Two additional existing springhead pools were identified as being suitable for dace without modification.  A total of 12 ponds and pools were made available as protected habitat, however, some of these required time for aquatic plants to develop prior to the actual translocation of Relict Dace.

Release of Relict DaceThe final phase of the project began in spring of 2012 with population counts of Relict Dace found in the three springs.  No more than 10% of each population was to be removed for translocation.  Therefore, eight Relict Dace were removed from one springhead, and 75 were removed from each of the other two pools.  These fish were carefully moved to nearby ponds that were created or enhanced for their specific needs.

Refuge staff, in partnership with NDOW fisheries biologists, will continue to monitor the Relict Dace populations in the years to come.  It is hoped that the dace will thrive and that additional translocations can be undertaken to further expand the population into all 12 project sites.  The success of this project is critical to the protection of Relict Dace in Ruby Valley.