The Woundfin (Plagopterus argentissimus) is endemic to the Virgin River in Utah, Arizona, and Nevada and has been federally listed as an endangered species since 1970. Recovery efforts for the endangered Woundfin involve maintaining broodstock and refuge populations, as well as providing production from these stocks to repopulate wild populations in the Virgin River after restoration activities or catastrophic events. Southwestern Native Aquatic Resources and Recovery Center (SNARRC), located in Dexter, New Mexico, has maintained a refuge and broodstock population since the 1970s, with a goal of producing 20,000 Woundfin for annual stocking since the early 2000s. The broodstock also serves as a refuge for Woundfin, providing redundancy in case of population collapse in the wild. A salvage, broodstock, and culture plan was established by the Utah Division of Wildlife (UDWR) in 2000 to ensure conservation and management strategies of Woundfin (Hepworth et al. 2000). The broodstock plan suggested that the captive stock be periodically supplemented (every year if possible) with wild fish, as long as feasible, in order to ensure that natural gene frequencies were unaltered between wild and captive populations (Hepworth et al. 2000). Also, to counter the effects of genetic drift, a study in 2009 by Chen et al., recommended that approximately 300 randomly selected individuals be added to the refuge/broodstock every 2 years as long as removal of these fish does not adversely affect wild populations. Initially, Woundfin from the Virgin River were brought to SNARRC in 1979 to establish a refuge population (Chen et al. 2009). However, no Woundfin collected before 1987 survived in captivity. The current stock is descended from 3,338 founders brought into the hatchery from 1987 to 1989. Between 2002 and 2004, 174 Woundfin were salvaged for broodstock when performing treatments to eradicate red-shiner between the Washington Fields and Johnson diversions. Additionally, 605 Woundfin were collected from seine hauls (n=165) below Palmer Ranch and near the Washington Fields Diversion on November 17, 2005 and were added to the broodstock.

Task 1: Collect and transport wild Woundfin to help bolster the current boordstock population at SNARRC and increase production for stocking efforts. Task 2: Maintain broodstock and propagation efforts and SNARRC to continue production and stocking of Woundfin to ensure the continued existence and recovery of the species.

Woundfin broodstock at SNARRC has not been supplemented with the numbers or frequency recommended by Chen et al. 2009 and Hepworth et al. 2000, due various obstacles/logistics (e.g., limited populations of wild Woundfin available for capture, summer monsoons/high flow events, and travel distance between the collection site and the hatchery). Since the last supplementation of Woundfin at SNARRC occurred almost two decades ago, the Virgin River Program and its partners have prioritized the augmentation of Woundfin broodstock at SNARRC. In July, 2024, wild Woundfin (n=559) were successfully collected from the Virgin River and transferred to SNARRC for broodstock/refuge supplementation. Continued supplementation is critical to maintain optimal genetics and reproductive fitness in the broodstock. In addition, federal funding is uncertain into the future, and maintenance of this broodstock is critical for Woundfin protection and recovery.

Virgin River Fishes Recovery Plan Virgin River Program Document Virgin River Management Plan

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All collections will occur under the Section 6 Cooperative Agreement between the Fish and Wildlife Service and the State of Utah.

This proposal would support additional collection and transportation of wild Woundfin in 2025, to help bolster the current broodstock population at SNARRC and increase production for stocking efforts. The use of captive Woundfin to supplement natural populations represents an important component of recovery efforts for the species. Therefore, until Woundfin populations reach a sustainable level, the continued production and stocking of Woundfin will be necessary to ensure the recovery of these native fish. Fish will be collected by UDWR staff using seines during July and August 2025, as opportunity allows. A holding facility will be established, likely at the water treatment facility at Quail Creek Reservoir until collection is complete. The fish will be transported by air, using state pilot resources. The success of this approach was demonstrated in 2024. The fish will be held in quarantine for a standard amount of time upon arrival at SNARRC.

The fish will be monitored for stress twice a day during their holding period before transport to SNARRC. At SNARRC, hatchery personnel will follow standard procedures to monitor the fish during quarantine. Success will be measured by successful broodstock supplementation with minimal mortality, as well as increased production for stocking in future years.

Wasington County Water Conservancy District Utah Department of Natural Resources Utah Division of Wildlife U.S. Fish and Wildlife Service Bureau of Land Management National Park Service U.S. Forest Service Shivwits Band of Paiutes The Nature Conservancy Washington County Farm Bureau Dixie Conservation District, Southwestern Native Aquatic Resources and Research Center

Collection of wild woundfin for broodstock supplementation should occur as recommended in the 2000 salvage, broodstock, and culture plan, but our ability to do so ultimately depends on ability to capture fish, and thus may need to be conducted opportunistically. Continued support of a captive refuge and broodstock population of Woundfin remains a top priority for the Virgin River Program until the wild Woundfin populations become self-sustaining in Utah.

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