326 



Inlcnor West — Our Living Rtsoiirci's 



For further information: 



Gordon Mueller 



National Biological Service 



PO Box 25007 D-8220 



Denver, CO 80225 



chemical contaminants were introduced and 

 have changed the river's delicate ecosystem. 



The dramatic dechne prompted the listing of 

 the bonytail as endangered in 1980. and a simi- 

 lar listing for the razorhack sucker followed in 

 1991. Although both fishes are federally pro- 

 tected and recovery programs began over 15 

 years ago, these species continue to edge toward 

 extinction. The problem lies in the complexity 

 of the environmental and legal issues, combined 

 with possible contlicts in land-, water-, and fish- 

 eiy-management philosophies. Controversy and 

 debate have slowed, stalled, and complicated 

 recovery effort. While sociopolitical issues of 

 recovery are debated, old relict populations are 

 not being aggressively protected through man- 

 agement and they continue to die off. 



Recovery and Management 



The goal of recovery is to reestablish species 

 or enhance their ability to maintain self-peipet- 

 uating populations in native habitat, which may 

 require both physical and biological habitat 

 restoration. Many scientists believe recovery of 

 bonytail and razorback sucker will take an 

 aggressive and long-term commitment. 

 Recovery efforts in the upper river are being 

 intensified to restore adequate spring flows and 

 develop nursery habitat. Stocking of bonytail 

 and razorback sucker is being postponed until 

 these habitat changes are made, and guidelines 

 for stocking recreational species and possibly 

 reducing their populations are being negotiated. 

 Whether these actions will be sufficient to 

 recoser these fish is unknown. 



While bonytail and razorback sucker are not 

 being stocked in the upstream recovery pro- 

 gram, they are being stocked farther down- 

 stream. A 10-year stocking program reintro- 

 duced razorback sucker into Arizona streams, 

 but although nearly 15 million razorbacks were 

 stocked between 1981 and 1990. the effort 



failed because most small suckers were believed 

 to have been eaten by catfish and other non- 

 native fishes. This emphasizes the need for 

 predator removal or the stocking of larger fish. 



Removal of non-native species is virtually 

 impossible and sometimes undesirable. Larger 

 bonytails and razorback suckers are being 

 stocked by the Native Fish Work Group to 

 attempt to maintain the Lake Mohave popula- 

 tion by replacing the old population with young 

 adults that exhibit the genetic characteristics of 

 the remnant population. Bonytail and razorback 

 suckers are being raised in isolated coves where 

 other fish have been removed. Fish grow to 

 about 30 cm (12 in) in length in a year and are 

 then released into the reservoir. At this size, 

 many should escape predation and could poten- 

 tially survive 40 to 50 years. 



Stocking is not an alternative to recovery, 

 but if done properly, it can be used to maintain, 

 expand, or reestablish long-lived endangered 

 fish populations. Lake Mohave is not pristine 

 habitat: however, maintenance of its population 

 can help preserve genetic diversity, enhance 

 species diversity in the reservoir, help ensure 

 against catastrophic loss of hatchery brood 

 stocks, and provide opportunities to study these 

 fish in the wild. 



Aggressive management of remaining popu- 

 lations is essential to provide the time to com- 

 plete and test habitat restoration programs. If 

 remnant populations are not saved, we stand to 

 lose important pieces of a very complex ecolog- 

 ical puzzle. 



References 



Dill. W.A. 1941. The fisherv' of the lower Colorado River 

 California Fish and Game 30:109-21 1. 



Miller. W.H.. H.M. Tyus. and C.A. Carlson, eds. 1982. 

 Fishes of the upper Colorado River system: pre.sent and 

 future. American Fisheries Society. Bethesda, MD. 1.^1 

 pp. 



Minckley. W.L., and J.E. Deacon, eds. 1991. Battle against 

 extinction: native fish management in the American 

 West. University of Arizona Press, Tucson. 517 pp. 



Amphibian 

 and Reptile 

 Diversity on 

 the Colorado 

 Plateau 



by 



Charles Drost 



Elena Deshler 



National Biological Service 



The Colorado Plateau region is an area of 

 high uplands, cut by the dramatic canyons 

 of the Colorado River system in northern 

 Arizona, northeastern New Mexico, eastern 

 Utah, and western Colorado (Figure). Habitats 

 within the region range from upland desert in 

 the lower stretches of the Colorado River to 

 small areas of alpine tundra on the highest 

 peaks. The amphibian fauna is relatively small 

 and dominated by species adapted to dry condi- 

 tions such as toads (genus Bufo) and spadefoot 

 toads (genus Scaphiopiis). Reptile species are 

 more numerous and varied, with the spiny 

 lizards (Sceloporus), whiptail lizards {Cneini- 

 dophorus). and garter snakes (Thamnophis) 

 well-represented. The reptiles and amphibians 



of the area have not been well-studied, although 

 several species are known or suspected to have 

 suffered recent declines. 



As part of an overall project to assess the 

 completeness of biological inventory informa- 

 tion on National Park Service lands (Stohlgren 

 and Quinn 1992), we compiled information 

 from species lists, literature reports, and limited 

 field work to prepare a preliminary data base of 

 amphibian and reptile occurrence on 25 park 

 areas in National Park Service lands on the 

 Colorado Plateau. 



Status and Trends 



The quality and completeness of amphibian 



