The Nature The Arizona Nature Conservancy conservancy 300 East University Boulevard, Suite 230, Tucson, Arizona 85705 (602) 622-3861 Memorandum To: Dan Campbell From: Peter Warren Re: Arizona native fishes Date: 26 August 1987 Here is some general information about the status oi native fish in Arizona and the Arizona Nature Conservancy's role in protecting threatened native fish. The pre-settlement fish fauna of Arizona consisted of 31 species of freshwater fish. Through introduction of exotic species, the number of resident fish in Arizona is now over 100 species. Many of the exotic species are either predatory upon or in competition with native species. A combination of introduced exotic species and loss of perennial stream habitat has sharply reduced the number and size of native fish populations. Of the 31 original native fish, one is extinct and four are extirpated in Arizona. Approximately half of the remaining native fish are currently listed or proposed for listing as Threatened or Endangered. Although recovery measures are being undertaken, the future of several of the endangered fish is by no means secure. For example, Woundfin survives only in a small part of the Virgin River and its small population could be easily destroyed. Major losses of native fish populations continue to occur. We have Just learned that all of the Mexican populations of Desert Pupfish in the Colorado River delta were apparently destroyed during the last three years due to introduction of Tilapia into the populations by floodwaters of 1983. The single most important factor in protecting the remaining native fish populations is preservation of habitat and insuring stable stream flows. In many situations this is a realistic goal because, due to historical land ownership patterns, most perennial streams are in private ownership and the potential exists for acquisition and protection. The Arizona Nature Conservancy has been responsible for protecting a number of key wetlands that support populations of threatened native fish. These are summarized here in three categories: 1) Preserves that TANC has retained ownership and manages, 2)Preserves that TANC acquired and transfered to other management, and 3) Potential preserves for which TANC is currently exploring acquisition and protection alternatives. Site Name Fish species protected Preserves retained in TANC ownership: Muleshoe Ranch Gila Chub Sonoita Creek Gila Topminnow Canelo Cienega Gila Topminnow Hassayampa River Woundfin - Potential reintroduction; Colorado Squawfish, Bonytail chub - Coop with USFWS for nursery in Palm Lake Preserves transferred to other management: Aravaipa Creek Spikedace, Loachminnow, (Defenders of Wildlife) Round-tailed Chub San Bernardino Ranch Yaqui Topminnow, Yaqui Chub (U.S. Fish and Wildlife) Yaqui Sucker, Yaqui Catfish Leslie Creek Yaqui Topminnow, Yaqui Chub, (U.S. Fish and Wildlife) Mexican Stoneroller, Potential Preserves under Investigation: Chevelon Creek Little Colorado Spinedace Little Colorado Sucker Eagle Creek Spikedace San Rafael Valley springs Gila Topminnow Babocomari Cienega Gila Chub, Gila Topminnow Virgin River Woundfin, Virgin River Round-tailed Chub, Virgin River Spinedace Cienega Creek Gila Topminnow, Gila Chub .