Dexter National Fish Hatchery and Technology Center 's (Dexter NFHTC) mission is to assist in recovery and long-term sustainability of endangered North American fish fauna by avoiding imminent population extinction and permanent loss of unique genetic resources. Dexter achieves its mission through improved propagation methods, maintenance of genetic refuge populations, development of captive broodstocks, fish production for reintroduction and research, applied research investigating important life history requirements and ecological factors limiting recovery, technical training, information exchange, and public education .

Abundant and widespread before the turn of the century, many native western fishes are now endangered. Entire fish communities and their habitats in this arid environment are at risk. With trends in population distribution and abundance declining, the status of many desert fishes is precarious, their long-term sustainability questionable. Land use and water development have reduced availability and quality of native fish habitats. Dam construction, in particular, is associated with elimination of spawning and nursery areas. Dams also block natural migratory corridors restricting fish movements required for gene exchange and recolonization. Continuous introduction of nonnative fishes into remaining habitat has further compromised survival of rare and threatened native fishes through competition, predation, new diseases, and genetic contamination. In response to threats to our natural flora and fauna, Congress passed the Endangered Species Act of 1973. Language in the Act requires the U. S. Fish and Wildlife Service to identify, list, recover, and protect threatened and endangered plant and animal species, including fishes .

The inability of a fish population to reproduce in its natural environment is a red flag warning that extinction is inevitable unless action is taken. Captive propagation offers an immediate intervention strategy to address this serious problem. Recovery programs for listed species have identified genetic conservation and captive breeding as essential components of long-term management programs. Shortly after passage of the Endangered Species Act of 1973, the Service began searching for a refuge facility to propagate imperiled fishes of the American Southwest and northern Mexico. In 1974 Service personnel in Albuquerque selected an old warmwater fish hatchery in southeastern New Mexico as the first location for this visionary enterprise.

Dexter National Fish Hatchery was constructed in 1931 and 1932 to produce warmwater game fish for stocking into federal and state waters throughout the Southwest. Ironically, many of these bodies of water were the result of the Federal government's efforts to develop water resources in the arid west for irrigation, flood control, power generation, and recreation. As water was developed, desert habitat was destroyed or altered. The indigenous fishes began to disappear. By 1978 Dexter's transformation from sport fish production and distribution was complete. Dexter's new mission reflected its new focus - recovering endangered fishes. Currently, no other facility has such a concentration of rare and endangered fish species with the responsibility to maintain, produce, and study such an array of unique native fishes for recovery purposes.

Dexter NFHTC is located in the Pecos River Valley of southeastern New Mexico. The facilities are near the small, agricultural community of Dexter in Chaves County, about 20 miles south of Roswell. Dexter NFHTC, perched at the northern edge of the Chihuahuan Desert, is devoted exclusively to the study, preservation, propagation, and reintroduction of threatened and endangered fishes. Indeed, Dexter's mission is crafted to support implementation of the Service's Action Plan for Fishery Resources and Aquatic Ecosystems, particularly, recovery and restoration of imperiled fishes of western North America. For high priority fish populations, Dexter provides artificial genetic refuge facilities, gene bank, and repository for frozen sperm and tissues. Dexter's propagation program is designed to maintain genetic integrity, physiological health, and behavioral characteristics of high priority fishes targeted for recovery. Fish produced at Dexter NFHTC have served many functions. Dexter provides fish of various sizes to reintroduce into suitable habitat as required by recovery and management programs. Acquisition and protection of suitable habitat is coupled with production and stocking healthy offspring from genetically sound broodstock. Not only have the fish raised at Dexter been stocked to restore and augment extirpated and depleted populations, they have also been used to establish genetic refuges at other locations, in research, as laboratory and museum specimens, and as educational aids in public schools, aquariums, zoos, and universities. As part of the National Fish Technology Center System, Dexter's applied research program is designed to develop, improve, and evaluate breeding, rearing, and maintenance strategies, methods, protocols, and equipment to meet quantitative and qualitative fish production and management goals.

Dexter's ecosystem responsibilities address management, research, and technology development needs for a number of ecosystems in the western United States and northern Mexico. The following ecosystems reflect 90% of Dexter's efforts and are listed in relative order of their priority - Upper and Lower Colorado, including the San Juan, the Virgin, and the Gila/Salt/Verde River systems; the Upper and Middle Rio Grande, including the Pecos and Mimbres River systems; and the Rio Yaqui of Sonora, Mexico.

Maintain genetic refuge populations and develop captive broodstocks of threatened and endangered fishes from western North America, including Chihuahua and Sonora Mexico.

Genetically identify, characterize, and maintain samples and data bases on all Southwestern threatened and endangered fishes.

Develop technology for short and long-term gamete storage of threatened and endangered fishes.

Develop genetics management methods and culture techniques to minimize hatchery influence on post-stocking behavior of reintroduced threatened and endangered fishes.

Produce fish for reintroduction, research, and other recovery activities.

Tiersch, T. R., W. R. Wayman, J. H. Williamson, O. T. Gorman, G. J. Carmichael, and C. R. Figiel, Jr. In Press. Cryopreservation of sperm of endangered Colorado squawfish. Cryobiology.

Morizot, D. C., J. H. Williamson, and G. J. Carmichael. In Press. Biochemical genetics of wild and hatchery Colorado pikeminnow. Transactions of the American Fisheries Society.

Jensen, B. L., J. Campoy-Favela, D. S. Cobble, J. E. Brooks, and F. Abarca. In Press. Status of the Native and Introduced Fishes of the Upper Rio Bavispe, Chihuahua and Sonora. In Proceedings of the Desert Fishes Council, La Paz, Baja California Sur.

Williams, C.M. In Press. Woundfin, Ich. and temperature. Proceedings of the Desert Fishes Council, Vol. XXIV.

Tiersch, T. R., C. R. Figiel, Jr., W. R. Wayman, J. H. Williamson, G. J. Carmichael, and O. T. Gorman. 2000. Cryopreservation of sperm of the endangered razorback sucker. pages 117-122 In T. R. Tiersch and P. M. Mazik, editors. Cryopreservation in aquatic species. World Aquaculture Society, Baton Rouge, Louisiana.

Nielsen, J. L., M. C. Fountain, J. Campoy-Favela, K. Cobble, and B. L. Jensen. 1998. Oncorhynchus at the southern extent of their range: a study of mtDNA control-region sequence with special reference to an undescribed subspecies of O. mykiss from Mexico. Environmental Biology of Fishes 51:7-23.

Tiersch, T. R., W. R. Wayman, C. R. Figiel, Jr., O. T. Gorman, J. H. Williamson, and G. J. Carmichael. 1997. Field collection, handling, and storage of sperm of endangered razorback sucker. North American Journal of Fisheries Management 17:167-173.

Carmichael, G. J., J. H. Williamson, O. T. Gorman, and T. R. Tiersch. 1996. Field propagation techniques for the endangered razorback sucker. North American Journal of Fisheries Management 16:963-966.

Modde, T., A. T. Sholz, J. H. Williamson, B. G. Haines, B. D. Burdick, and F. K. Pfeifer. 1995. An augmentation plan for razorback sucker in the upper Colorado River basin. Pages 102-111. In H.L. Schramm and R. G. Piper, editors. Uses and effects of cultured fishes in aquatic ecosystems. American Fisheries Society, Bethesda, Maryland.

Platania, S. P., K. R. Bestgen, M. A. Moretti, D. L. Propst, and J. E. Brooks. 1991. Status of Colorado squawfish and razorback sucker in the San Juan River, Colorado, New Mexico, and Utah. The Southwestern Naturalist 36(1):147-150.

Hamman, R. L. 1989. Survival of Colorado squawfish cultured in earthen ponds. The Progressive Fish-Culturist 51:27-29.

Marsh, P. C., and J. E. Brooks. 1989. Predation by ictalurid catfishes as a deterrent to reestablishment of hatchery-reared razorback suckers. The Southwestern Naturalist 34(2):188-195.

Hamman, R. L. 1987. Survival of razorback suckers cultured in earthen ponds. The Progressive Fish-Culturist 49:138-140.

Hamman, R. L. 1986. Induced spawning of hatchery-reared Colorado squawfish. The Progressive Fish-Culturist 48:72-74.

Hamman, R. L. 1985. Induced spawning of hatchery-reared razorback suckers. The Progressive Fish-Culturist 47:187-189.

Hamman, R. L. 1985. Induced spawning of hatchery-reared bonytail. The Progressive Fish-Culturist 47:239-241.

Marsh, P. C. 1985. Effect of incubation temperature on survival of embryos of native Colorado River fishes. The Southwestern Naturalist 300:129-140.

Minckley, W. L., and B. L. Jensen. 1985. Replacement of Sonoran topminnow by Pecos gambusia under hatchery conditions. The Southwestern Naturalist 30(3):465-466.

Hubbs, C., and B. L. Jensen. 1984. Extinction of Gambusia amistadensis, an endangered fish. Copeia 1984(2):529-530.

Hamman, R. L. 1982. Induced spawning and culture of bonytail chub. The Progressive Fish-Culturist 44:201-203.

Hamman, R. L. 1982. Spawning and culture of humpback chub. The Progressive Fish-Culturist 44:213-216.

Hamman, R. L. 1981. Hybridization of three species of chub in a hatchery. The Progressive Fish-Culturist 43:140-141.

Hamman, R. L. 1981. Spawning and culture of Colorado squawfish in raceways. The Progressive Fish-Culturist 43:173-177.

Hamman, R. L. 1981. Transporting endangered fish species in plastic bags. The Progressive Fish-Culturist 43:212-213.

Williamson, J. H. In Press. Broodstock development and spawning. In R. Stickney, editor. Fish hatchery management. American Fisheries Society.

Kapuscinski, A. R., C. R. Steward, M. L. Goodman, C. C. Krueger, J. H. Williamson, E. Bowles, and R. Carmichael. In Press (Fisheries Bulletin). Genetics conservation guidelines for salmon and steelhead supplementation. Northwest Power Planning Council Agreement No. 90-037. Portland, OR.

Jensen, B. L. In Press. Fish refugia and captive propagation: A viable aid to conservation and restoration. In Proceedings of the First National Seminar on the Endangered Fishes of India, Allahabad, Uttar Pradish, India.

Williamson, J. H. In Press. Planning guidelines for genetics conservation and management of endangered fishes of the upper Colorado River basin. Recovery Implementation Program for Endangered Fish Species in the Upper Colorado River Basin. U. S. Fish and Wildlife Service.

Jensen, B. L. In Press. Consultation report on fish genetic resource conservation and management of the indigenous fishery resources of India with an emphasis on threatened and endangered species. Winrock International (USAID Agriculture Research Project), 7, Doorvi Marg, Vasant Vihar, New Delhi, 110 057, India. 28pp.

Williamson, J. H., D. C. Morizot, and G. J. Carmichael. 1998. Biochemical genetics of endangered Colorado pikeminnow from the Green, Yampa, Colorado, and San Juan rivers. Final draft report to the recovery program. Project number FY93 #23.

Williamson, J. H., R. S. Wydoski, and L. Visscher. 1994. Genetics management guidelines. Recovery implementation program for listed and candidate fish species in Region 6. U. S. Fish and Wildlife Service. Denver, Colorado.

Williamson, J. H., and R. S. Wydoski. 1994. Genetics management guidelines. Recovery implementation program for endangered fishes in the upper Colorado River basin. U. S. Fish and Wildlife Service, Denver, Colorado.

Abarca, F., K. L. Young, B. L. Jensen, I. Parra, R. H. Battaso, and K. Cobble. 1994. Yaqui River fishes relevant to the Madrean Province; U. S. - Mexico collaborations. In Proceedings of the Symposium on Biodiversity and Management of the Madrean Archipelago, Tucson, AZ.

Hamman. R. L., J. E. Johnson, and H. M. Tyus. 1994. Colorado squawfish. Pages 364-365 In life on the edge - a guide to california’s endangered natural resources: Wildlife Biosystems Books, Santa Cruz, CA. 550pp.

Scholz, A. T., M. B. Tilson, R. J. White, S. A. Holton, B. Haines, B. Jensen, and R. Hamman. 1994. Thyroxine induced chemical imprinting in Colorado squawfish (Ptychocheilus lucius) and razorback sucker (Xyrauchen texanus): Results of 1993 investigations. Eastern Washington University, Department of Biology, Cheney, WA. Colorado River Fisheries Chemoreception Project. Technical Report No. 5. 43 pp. Submitted to: U. S. Department of Interior, Bureau of Reclamation, Salt Lake City, UT. Cooperative Agreement No. 2-FC-40-11830.

Williamson, J. H. 1993. Genetics management guidelines for endangered fish species in the upper Colorado River basin. Recovery implementation program for endangered fishes in the upper Colorado River basin. U. S. Fish and Wildlife Service, Denver, Colorado.

Wydoski, R., J. H. Williamson, and D. Toney. 1993. Coordinated hatchery facility plan. U. S. Fish and Wildlife Service. Presented to Management Committee.

Williamson, J. H. 1993. Planning guidelines for genetics management of endangered fish species in the upper Colorado River basin. Presented to Propagation Subcommittee.

Burdick, B. D., and R. L. Hamman. 1992. A study to evaluate several tagging and marking systems for Colorado squawfish, razorback sucker, and bonytail. Report to the Recovery Implementation Program, U. S. Fish and Wildlife Service. Denver, CO. 66 pp.

Brooks, J. E., S. P. Platania, and D. L. Propst. 1991. Effects of Pecos River reservoir operation on the distribution and status of Pecos bluntnose shiner (Notropis simus pecosensis): preliminary findings. Report for Bureau of Reclamation, Salt Lake City, UT and Albuquerque., NM, and U. S. Fish & Wildlife Service, Albuquerque., NM. 14 pp.

Johnson, J. E., and B. L. Jensen. 1991. History and operation of endangered species hatcheries. Pages 197-217. In Battle Against Extinction - Native Fish Management in the American West, W. L. Minckley and James E. Deacon, Eds. The University of Arizona Press, Tucson.

Minckley, W. L., P. C. Marsh, J. E. Brooks, J. E. Johnson, and B. L. Jensen. 1991. Management toward recovery of the razorback sucker. Pages 303-357. In Battle Against Extinction - Native Fish Management in the American West, W. L. Minckley, and James E. Deacon, Editors. The University of Arizona Press, Tucson.

Jensen, B. L. 1990. Colorado squawfish reintroduction efforts in the lower Colorado River basin. Endangered Species Update, 8:(1), School of Natural Resources, The University of Michigan, Ann Arbor.

Brooks, J. E., and M. K. Wood. 1988. A survey of the fishes of Bitter Lake National Wildlife Refuge, with an historic overview of the game and nongame fishes. U. S. Fish and Wildlife Service, Albuquerque., NM. 20 pp.

Echelle, A. A., A. F. Echelle, and D. R. Edds. 1988. Genetic structure of three species of endangered desert fishes. Final Project Report - U. S. Fish & Wildlife Service, Albuquerque., NM. 97 pp.

Papoulias, D. 1988. The effect of food availability on growth and mortality of larval razorback sucker, Xyrauchen texanus. Final Report. U. S. Fish and Wildlife Service, Albuquerque., NM. 32 pp.

Papoulias, D. 1988. Survival and growth of larval razorback sucker, Xyrauchen texanus. Arizona State University. Master thesis. 83 pp.

Brooks, J. E. 1986. Status of natural and introduced Sonoran topminnow (Poeciliopsis o. occidentalis) populations in Arizona through 1985. U. S. Fish and Wildlife Service, Endangered Species and Fishery Resources, Albuquerque., NM. 33 pp.

Rinne, J. N., J. E. Johnson, B. L. Jensen, A. W. Ruger, and Roger Sorensen. 1986. The role of hatcheries in the management and recovery of threatened and endangered fishes. Pages 271-285. In Fish Culture In Fisheries Management, Proceedings of a Symposium on the Role of Fish Culture in Fisheries Management, Richard H. Stroud, Editor. Fish Culture Section and Fisheries Management Section of the American Fisheries Society, Bethesda, Maryland.

Minckley, W. L. 1985. Evaluations and suggestions concerning personnel, facilities, and programs at Dexter National Fish Hatchery. Report for the U. S. Fish and Wildlife Service. 15 pp.

Inslee, T. D. 1983. A study of the fisheries on Bitter Lake NWR. U. S. Fish and Wildlife Service, Albuquerque., NM. 12 pp.

Inslee, T. D. 1983. Spawning and hatching of the Colorado squawfish (Ptychocheilus lucius). U. S. Fish and Wildlife Service, Dexter NFH, Dexter, NM. 17 pp.

Jensen, B. L. 1983. Culture techniques for selected Colorado River imperiled fishes. Proceedings of the Thirty-Fourth Annual Northwest Fish Culture Conference, Moscow, Idaho. 12 pp.

Hamman, R. L. 1982. Induced spawning and culture of the humpback chub and bonytail chub hybrids. Pages 129-136. In Final Report of the U. S. Fish and Wildlife Service and U. S. Bureau of Reclamation, Part 3. Colorado River Fishery Project, Salt Lake City, UT.

Hamman, R. L. 1982. Spawning and culture of Colorado squawfish in a raceway environment. Pages 137-144. In Final Report of the U. S. Fish and Wildlife Service and U. S. Bureau of Reclamation, Part 3. Colorado River Fishery Project, Salt Lake City, UT.

Hamman, R. L. 1982. Spawning and culture of humpback chub. Pages 159-167. In Final Report of the U. S. Fish and Wildlife Service and U. S. Bureau of Reclamation, Part 3. Colorado River Fishery Project, Salt Lake City, UT.

Hamman, R. L. 1982. Induced spawning and culture of bonytail chub. Pages 169-175. In Final Report of the U. S. Fish and Wildlife Service and U. S. Bureau of Reclamation, Part 3. Colorado River Fishery Project, Salt Lake City, UT.

Inslee, T. D. 1982. Spawning and hatching of the razorback sucker (Xyrauchen texanus). Proceedings of the Annual Conference of the Western Association of Fish and Wildlife. Agencies, 62:431-432.

Inslee, T.D. 1982. Spawning of razorback suckers. Pages 145-157. In U. S. Fish and Wildlife Service and U. S. Bureau of Reclamation, Part 3. Colorado River Fishery Project, Salt Lake City, UT.

Inslee, T. D. 1981. Overwintering Gila topminnows. Poeciliopsis occidentalis. 3 pp.

Kapuscinski, A. R., C. R. Steward, M. L. Goodman, C. C. Krueger, J. H. Williamson, E. Bowles, and R. Carmichael. 1993. Genetic conservation guidelines for salmon and steelhead supplementation. Fishery Bulletin: In Preparation. ( Synthesis paper from Northwest Power Planning Council workshop, January 1991.)

Williamson, J. H. 1993. State of Colorado hatchery feasibility study for endangered fishes in the upper Colorado River basin. Colorado Water Conservation Board; Submitted draft to Biology and Management Committees.

A major project at Dexter is rebuilding the razorback sucker broodfish population. Each year offspring from paired mating of wild razorback suckers from Lake Mohave, on the Colorado River, are brought to Dexter for grow-out, ultimately replacing the current broodfish, which are getting very old. Cooperators are Willow Beach NFH, AZ; Mora NFHTC, NM; Grand Canyon Research Project, Flagstaff, AZ; Louisiana State University, Baton Rouge.

Another project involves development of a Regional genetics laboratory at the Technology Center. The Game and Fish Department of The State of New Mexico, New Mexico State University, the U. S. Geological Survey, Biological Research Division, and private interests all are partnering in this effort.

Genetic status of Colorado squawfish (now pikeminnow) populations was determined by Technology Center personnel and it is anticipate that the Center will need to develop additional broodstock from the Colorado and Green Rivers. Currently Dexter is developing a Colorado mainstem population 91991 year class) of Colorado pikeminnow.

Dexter will soon begin developing a new second generation of bonytail to replace the original hatchery stock developed in 1981. New Chihuahua chub and Yaqui catfish broodstocks are being developed as well.

Dexter is producing advanced fingerling bonytail for recovery efforts in the Colorado River. Fish are spawned at the facility and some are retained and grown out. Additional bonytail are transferred for grow-out to the Willow Beach NFH on the Colorado River below Hoover Dam.

Dexter continues efforts to develop and test diets for endangered fishes in cooperation with Bozeman Fish Technology Center and several field stations in the upper and lower Colorado River basins.

Other refugium populations are being maintained for various species. The number of species maintained at Dexter changes frequently, depending upon need. Dexter is not meant as a final solution to saving endangered fishes. The Endangered Species Act also calls for the protection of the habitat on which listed species depend for their continued existence. Although human activities have tremendously impacted the aquatic ecosystems of the Southwest, these activities played an important role in the economic development of the region. The goal of the U. S. Fish and Wildlife Service is to coordinate development with the needs of fish and wildlife. Hindsight, it is often said, is the best teacher. We can see some of the mistakes we have made in the past and hopefully learn from them. With careful and intelligent planning, loss of our natural resources, including the elimination of species, need not be the price for modern progress.

List and status of species held at Dexter NFH & TC: Species (Acronym); Scientific name; Federal status. [E = Endangered; T = Threatened P = Proposed for listing in Federal Register.

Family Catostomidae: Razorback sucker (RBS) Xyrauchen texanus T; Lost River sucker (LRS) Deltistes luxatus E; Shortnose sucker (SNS) Ghasmistes brevirostris E; Warner sucker (WAS) Catostomus warnerensis E.

Family Cyprinidae: Colorado squawfish (CSF) Ptychocheilus lucius E; Bonytail chub (BTC) Gila elegans E; Chihuahua chub (CCH) Gila nigrescens T; Pahranagat roundtail chub (PRG) Gila robusta jordani E; Virgin River roundtail chub (VRC) Gila robusta seminuda E; Woundfin (WDF) Plagopterus argentissimus E; Guzman beautiful shiner (GBS) Notropis f. formosus T.

Family Ictaluridae: Yaqui catfish (YCF) Ictalurus pricei T.

Family Cyprinodontidae: Leon Springs pupfish (LSP) Cyprinodon bovinus E; Desert pupfish (DEP) Cyprindon macularius E.

Family Poeciliidae: Gila topminnow (GTM) Poeciliopsis o. occidentalis E; Big Bend Gambusia (BBG) Gambusia gaigei E.