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rficlcs Table 1. Status of native and nonnative freshwater fishes of the lower Colorado River main stem, southwestern United States. Common and scientific names LCR status ESA status Native species Family Cyprinidae, minnows Humpback chub, Gila cypha Grand Canyon Endangered Bonytail, Gila elegans Lakes Havasu and Mohave Endangered Roundtail chub, Gila robusta Extirpated from main stem Woundfin, Plagopterus argentissimus Extirpated from main stem Endangered Colorado squawfish, Ptychocheiius lucius Extirpated from lower basin Endangered Speckled dace, Rhinichthys osculus Grand Canyon Family Catostomidae, suckers Bluehead sucker, Pantosteus discobolus Grand Canyon Flannelmouth sucker, Catostomus latipinnis Grand Canyon' Razorback sucker, Xyrauchen texanus Primarily reservoirs Endangered Family Cyprinodontidae, killifishes and pupfishes Desert pupfish, Cyprinodon marularius Sonora, Baja, CA Endangered Nonnative species Family Clupeidae, shads and herrings Threadfin shad, Dorosoma petenense Reservoirs Family Salmonidae, trouts and salmons Rainbow trout, Oncorhynchus mykiss Coid-water reaches, reservoirs Family Cyprinidae, minnows Red shiner, Cyprinella lutrensis Mostly riverine Common carp, Cyprinus carnin Ubiquitous Family Ictaluridae, freshwater catfishes Bullhead catfishes, Ameiurus spp. Widespread Channel catfish, Ictalurus punctatus Widespread Flathead catfish, Pylodictis olivaris Lake Havasu and below Family Poeciliidae, live-bearers Mosquitofish, Gambusia affinis Ubiquitous Mollies, platyfish; Poecilia spp., Xiphophorus spp. Lowermost reach Family Centrarchidae, basses and sunfishes Sunfishes, Lepomis spp. Ubiquitous Smallmouth bass, Micropterus dolomieui Localized Largemouth bass, Micropterus salmoides Widespread White crappie, Pomoxis annularis Reservoirs Black crappie, Pomoxis nigromaculatus Reservoirs Family Moronidae, temperate basses Striped bass, Morone saxatilis Widespread Family Cichlidae, cichlids African cichlids, Oreochromis spp., rhapia zilli Localized to widespread below Lake Havasu; one species established in Lake Mead Note. LCR is lower Colorado River (Glen Canyon Dam downstream to the Gulf of California); ESA is the Endangered Species Act of 1973, as amended. a. A reestablished population of flannelmouth suckers also occupies a short river reach downstream of Davis Dam, which impounds lake Mohave. 1991). Progress toward recovery was defined by a series of "reasonable and prudent alternatives" in lieu of jeopardy opinions under section 7 of the ESA (Lochhead 1996). Ex- amples of such alternatives include provision of research funds and purchase of land on which occupied habitat could be developed. Recent examination of the success of the RIP's consensus-based approach suggests that conservation goals have been compromised by a process that relies on funding from water development interests and is focused on achiev- ing bureaucratic procedural goals (Brower et at. 2001). This long-term, multimillion-dollar program has established massive administrative and research infrastructures, but according to some informed observers it has accomplished lit- tle to improve the status of the listed fishes. Concentrating efforts in the upper basilr de-emphasized the lower Colorado River basin (USFWS Region 2), where im- portant humpback chub and razorback sucker populations existed along with the last wild bonytail (Marsh and Minck- ley 1992, Valdez and Carothers 1998). Independent workers nonetheiess proceeded with research and management funded by diverse sources. But native fishes and their habitats con- tinued to decline. "Nonessential" endangered fishes were March 2003 / Vol. 53 No. 3 • BioScience 221