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FOREWORD Clarence A. Carlson The rare native fishes of the Upper Colorado River System have been the subject of considerable interest and contention for decades, but research on them intensified in the 1970's and early 1980's. Because many research efforts had recently culminated or were nearing completion, a committee consisting of Bill Miller, Darrel Snyder, Ed Wick, and I began early last year to arrange a series of papers on these fishes for presentation at the 1981 meeting of the American Fisheries Society. Our in- tent was to focus attention on a subject of major in- terest to western fishery biologists, concentrating on research conducted after 1975 on fishes of the in- termediate and lower (large-river) habitat zones in the Upper Colorado River Basin. Our objectives were to: (1) present basic information about these fishes, (2) identify critical needs for recovery or con- tinued existence of rare fishes, (3) emphasize life history and status of rare and endangered fishes, and (4) consider impacts on fishes of past human ac- tions and anticipate future impacts as water use in- creases. A secondary goal was to provide a basis and opportunity for discussion regarding what can be done to preserve the native fishes of the Upper Col- orado River System in light of human needs, legal constraints, and political realities. Participation of a diverse group of experts was obtained, and written versions of their presenta- tions comprise these proceedings. Eileen Carlson and I have provided background and introduced the Upper Colorado River System and its fishes through a brief literature review. Bob Shields presented a summary of biological and political problems en- countered by resource agencies responsible for water management and endangered species in the Upper Basin. He introduced the Colorado River Fishery Project and the Conservation Plan ap- proach to resolving conflicts. Harold Tyus spearheaded a cooperative effort to summarize cur- rent data on fish species in the Upper Colorado River System, including a breakdown on numbers of native, introduced, endemic, and rare fishes. Tyus and his co-authors also charted fish distribution, relative abundance, and preferred habitats in rivers and their incidence in reservoirs. Bob Jacobsen discussed energy and mineral development, water development, and transporta- tion expansion in the Upper Basin. These activities, associated with massing of people, are expected to result in fish and wildlife habitat losses and other adverse effects, which will require cooperative ef- forts to minimize their impacts. Mike Prewitt and Clair Stalnaker suggested establishment of habitat and population-enhancement programs based on modeling of flow regimes. Ron Lambertson stated that mitigation tradeoffs are not acceptable for en- dangered species under Section 7 of the Endangered Species Act, but a comprehensive effort by resource agencies should allow protection of natural ecosystems (and listed fishes) while responsible economic growth and development proceed. Reed Harris and his co-authors discussed natural flows in Upper Basin streams, the extent of present water use, and legal constraints on use of Upper Basin water. Some rather surprising estimates of future flows as a percentage of natural flows were presented. Flexibility in methods of using water will decrease with water supply, and more compromises will be necessary. Bob Behnke fully recognizes the inevitability of compromise and doubts that en- dangered fishes will be protected at the expense of economic "benefit". He concluded his presentation by proposing creation of an independent agency to study and monitor effects of habitat alterations. This agency would be funded by taxes on benefits from human activities that alter the environment. Kent Miller described the Colorado River Fishes Recovery Team and summarized its philosophy, ac- tivities, and methods of accomplishing recovery plan goals. Paul Holden, Rich Valdez, Ed Wick and their co-authors emphasized new data on the life histories of the rarest endemic fishes of the system and discussed reasons for declines and prospects for sav- ing these fishes from extinction. Little optimism was expressed about the future of the Colorado squawfish, razorback sucker, humpback chub, and, especially, the bonytail chub in the Upper Colorado River Basin. A panel consisting of Bob Behnke, Paul Holden, Ron Lambertson, Bill Miller, Phil Sharpe, and Clair Stalnaker presented additional information and ad- dressed audience concerns. The discussion was ably led and summarized by Dick Wydoski. Bill Miller's closing remarks concluded the symposium. V