Planned Restoration of the Crystal Spring Outflow Ecosystem at Ash Meadows National Wildlife Refuge

Authors: Ambre Chaudoin, Michael Bower, Shannon Hurn, Christa Desroberts

Year: 2024

Abstract

Crystal Spring, the largest spring in terms of discharge and area of influence at Ash Meadows National Wildlife Refuge, is the target of a planned restoration project. The project will build on an earlier restoration of the springhead and initial outflow reach in 1996. Downstream of the restored reach the spring outflow currently enters a series of irrigation ditches that feed Crystal Reservoir and other areas. A nomination for Southern Nevada Public Lands Management Act funding was approved in 2023, making restoration of the remainder of the outflow ecosystem possible. The project’s primary goal is to restore the ecological function of habitats and support the unique array of native and endemic fish, wildlife, and plants the wildlife refuge was created to protect. Visitor access and interpretation enhancements including a new trail segment and overlooks are being incorporated to increase opportunities for environmental education and enjoyment of the unique setting. Restoration plans include reclamation of irrigation ditches and dikes, decommissioning of Crystal Reservoir, creation of natural spring outflow habitats, treatment of priority invasive plants, and eradication of non-native sport fishes. Several science collaborations have been initiated to inform restoration design and adaptive management of sensitive resources that may be impacted during implementation. These include 1) a hydrological investigation to determine water sources supporting endangered Amargosa niterwort (Nitrophila mohavensis) populations below Crystal Reservoir, 2) development of an Amargosa niterwort habitat suitability model, 3) experimental propagation and planting trials in vacant Amargosa niterwort habitats, 3) a focused eDNA surveillance and active control effort to eradicate green sunfish (Lepomis cyanellus), 4) development of additional eDNA assays for invasive fish surveillance and monitoring of fish population status, and 5) a pilot study to test and refine formal methods for fish and aquatic invasive species monitoring. An overview including the history of habitat alteration and restoration in the Crystal Spring system, conceptual designs for restoration of the lower Crystal Spring system, the many collaborations being developed to support the project, and an implementation timeline will be shared.