Rehabilitation of School Spring, Ash Meadows, Nevada to improve habitat quality for Warm Springs pupfish, Cyprinodon nevadensis pectoralis, and its cohabiting thermal endemic invertebrates

Authors: Robert J. Andress, Sharon D. McKelvey, Cristi R. Baldino, Darrick S. Weissenfluh, Shawn C. Goodchild, Gayton G. Scoppettone

Year: 2008 (xl)

Abstract

School Spring is one of six low discharge thermal springs within the Warm Springs complex, on the Ash Meadows National Wildlife Refuge. Springs within the complex occur within a 500 m radius, and are sufficiently isolated from other Ash Meadows springs, to harbor their own endemic biota, premiere of which is the Warm Springs pupfish Cyprinodon nevadensis pectoralis. This unique biota is imperiled due to habitat alteration and invasion of non-native species prior to the area becoming a National Wildlife Refuge. Ash Meadows National Wildlife personnel have given the Warm Springs complex high priority for restoring its habitat and extirpating non-native species. Rehabilitation of School Spring is an important first step in restoring the Warm Springs complex to a semblance of its historic condition. The rehabilitation goal was to create habitat that would be a strong-hold for C. nevadensis pectoralis and its cohabiting endemic invertebrates while other Warm Spring complex spring systems are being restored. School Spring was selected for rehabilitation because its thermal endemic invertebrates had been previously extirpated and it had been serving as a C. nevadensis pectoralis refuge for the past 25 years. Our rehabilitation efforts included the removal of the deteriorating concrete ponds serving as the pupfish refuge; construction of a semi-natural stream channel in the vicinity of the historical spring outflow channel; improving the hydraulic and thermal conditions to accommodate thermal endemic invertebrates as well as C. nevadensis pectoralis; and eradicating non-native species. Monitoring to date indicates that the red swamp crayfish Procambarus clarkii and mosquitofish Gambusia affinis have successfully been eradicated from the system, and C. nevadensis pectoralis flourish. We are presently working on re-introduction of thermal endemic invertebrates.