2010 Area report for Nevada

Authors: Darrick S. Weissenfluh, Eric S. Miskow, Brian M. Hobbs, Jon C. Sjoberg, Cody Byrne, Jeff Petersen, Mark Pepper

Year: 2010 (xlii)

Abstract

Brief updates on the population status and management of key Nevada native aquatic taxa are presented. The U.S. Fish and Wildlife Service is currently constructing the Amargosa Pupfish Research Station in Ash Meadows National Wildlife Refuge to provide for propagation of redundant populations of the endangered Devils Hole pupfish, Cyprinodon diabolis, in an artificial refuge, and for research support. Also in Ash Meadows, populations of two endangered fish species, Ash Meadows Amargosa pupfish, Cyprinodon nevadensis mionectes, and Ash Meadows speckled dace, Rhinichthys osculus nevadensis, were monitored in November 2009. The population estimates for both species declined from the last estimates in 2007. The U.S. Fish and Wildlife Service completed a 5 year review of C. n. mionectes, and concluded that no change in the listing status was warranted. In the Muddy River Warm Springs complex, ongoing restoration projects and eradication efforts of non-native blue tilapia, Oreochromis aureus, continue to increase suitable habitat for the endangered Moapa dace, Moapa coriacea; the most recent population surveys in August have revealed an increase from the low counts of 2008. In eastern Nevada, the endangered Clover Valley speckled dace, Rhinichthys osculus oligoporus, was surveyed for the second year in a row by NDOW to monitor and evaluate population status. The once thought-to-be extirpated Diamond Valley speckled dace, Rhinichthys osculus ssp., may still be extant; a survey effort by NDOW this past summer found two populations of dace in the Pluvial Lake Diamond. Tissue samples are being examined to determine lineage. In addition to species updates, restoration efforts that enhance habitats for the threatened desert dace, Eremichthys acros, threatened Railroad Valley springfish, Crenichthys nevadae, endangered White River spinedace, Lepidomeda albivallis, and Wall Canyon sucker, Catostomus sp., are discussed. Through successful partnerships with tribal, state, and federal agencies, as well as private landowners, habitat and numbers of C. nevadae, and Dixie Valley tui chub, Siphateles bicolor ssp., were improved. Additionally, cooperative efforts prevented the Amargosa toad, Anaxyrus nelsoni, from becoming listed as the 12 month finding by U.S. Fish and Wildlife Service found it ‘Not Warranted’.