Comparison of aquatic habitat restoration projects at multiple scales at Ash Meadows National Wildlife Refuge: Recovery of the Ash Meadows Amargosa pupfish Cyprinodon nevadensis mionectes, Warm Springs pupfish, Cyprinodon nevadensis pectoralis, Ash Meadows speckled dace, Rhinichthys osculus nevadensis, and endemic aquatic invertebrate species

Authors: Robert J. Andress, Chad R. Gourley, Sharon D. McKelvey, Cristi R. Baldino, Darrick S. Weissenfluh, Gayton G. Scoppettone

Year: 2010 (xlii)

Abstract

Aquatic habitat restoration associated with the recovery of endemic species including Ash Meadows Amargosa pupfish, Cyprinodon nevadensis mionectes, Warm Springs pupfish, Cyprinodon nevadensis pectoralis, Ash Meadows speckled dace, Rhinichthys osculus nevadensis, and several endemic aquatic invertebrate species has been completed at multiple locations and scales at Ash Meadows National Wildlife Refuge. Each restoration project required a unique approach to design and implementation due to differences in restoration goals, site history, habitat requirements, and project size. While the recovery of federally-listed species was the overarching goal, ecosystem recovery via the restoration of hydrologic processes and native plant communities was the guiding principle behind all projects. The aquatic habitat restoration process to date has focused more on the creation of suitable and sustainable habitat than on replication of pristine habitat. However, consideration of pre-disturbance or pristine conditions, predicting the long term trajectory of created or restored habitat, and eradication of invasive species is always discussed during the planning process and incorporated during implementation when feasible. Aquatic habitat restoration projects completed to date have revealed promising indicators of success while continually informing planning and management efforts. A dramatic shift toward dominance by native fish species over non-native fish species has occurred at Kings Spring and Point of Rocks completed in 1998 and 2002 respectively. Jackrabbit Spring restoration, completed in 2007, resulted in a localized increase of R. osculus nevadensis abundance while ongoing monitoring indicates the increase may have been temporary or due to a change in distribution. Habitat constructed at School Spring in 2008 resulted in at least a 250% increase in C. nevadensis pectoralis abundance and facilitated successful repatriation of endemic aquatic invertebrate species. Results from monitoring the repatriation of R. osculus nevadensis in the recently restored Fairbanks Spring outflow channel (2009-2010) are preliminary but recruitment has been observed. The most critical elements common to each project were a diverse planning group and extensive onsite planning. Overall, each project has been highly successful to date with regard to species recovery and terrestrial and aquatic habitat restoration. However, success can be temporary as changes in habitat conditions or food web may result in the loss of populations that expanded immediately following restoration. Long term commitment, monitoring, and maintenance are required to continue improving restoration methods and ensure success.