Virgin Spinedace Restoration in the Santa Clara River below Gunlock Reservoir

Authors: Martin Schijf, Rick Fridell, Christian Edwards, Melinda Bennion, Erik Woodhouse, Kody Callister, Sarah Siefken

Year: 2022

Abstract

The Virgin Spinedace, Lepidomeda mollispinis, is a minnow endemic to the Virgin River Basin. In 1994, the species was proposed for federal listing under the Endangered Species Act (ESA) due to population declines resulting from habitat loss and degradation. At the time of the listing proposal, Virgin Spinedace distribution had declined to approximately 60% of its historic distribution within the Virgin River Basin. In response to the proposed federal listing, the Virgin Spinedace Conservation Agreement and Strategy (VSCAS) was initiated in 1995. The VSCAS was critical in establishing collaborative partnerships to provide resources and cooperative efforts to conserve and enhance Virgin Spinedace populations throughout their range. The VSCAS outlines conservation actions intended to reverse declines and enhance Virgin Spinedace by protecting and expanding extant populations and reestablishing extirpated populations. One of the primary goals of the VSCAS was to increase the range of Virgin Spinedace from 60% to at least 80% (~ 185 km; 115 mi of linear riverine habitat) of its historically occupied habitat by protecting and expanding extant populations and re-establishing extirpated populations. The U.S. Fish and Wildlife Service determined that full implementation of management actions outlined in the VSCAS would alleviate the factors that led to the decline in Virgin Spinedace populations, and eliminate the necessity for an ESA listing. Restoration of population maintenance flows to reestablish viable Virgin Spinedace populations in dewatered or depleted stream reaches is a primary objective in the VSCAS. The Santa Clara River below Gunlock Reservoir was identified as a key Virgin Spinedace restoration reach. Our presentation outlines the success of collaborative efforts implemented by VSCAS signatories and other key partners to restore population maintenance flows and Virgin Spinedace populations in the Santa Clara River below Gunlock Reservoir.