FWS/OBS-77/62 September 1977 AN EVALUATION OF THE STATUS, LIFE HISTORY, AND HABITAT REQUIREMENTS OF ENDANGERED AND THREATENED FISHES OF THE UPPER COLORADO RIVER SYSTEM By Timothy W. Joseph, Ph. D. James A. Sinning, M.S. ECOLOGY CONSULTANTS, INC. 1716 Heath Parkway Fort Collins, Colorado 80526 Co-authors Robert J. Behnke, Ph. D. Colorado State University Paul B. Holden, Ph. D. Biowest Western Water Allocation Project Funds Interagency Agreement Number Contract Number EPA-IAG-D7-E685 14-16-0009-77-012 Mr. Clinton Hall, Director Carl Armour, Project Officer Energy Coordination Staff Western Energy and Land Use Team Office of Energy, Minerals 2625 Redwing Road and Industry Fort Collins, Colorado 80526 Environmental Protection Agency Washington, D. C. 20460 This study was conducted as part of the Federal Interagency Energy/Enviromlntal Research and Development Program U.S. Environmental Protection Agency Performed for Western Energy and Land Use Team Office of Biological Services Fish and Wildlife Service U.S. DEPARTMENT OF THE INTERIOR TABLE OF CONTENTS Page PREFACE ACKNOWLEDGEMENTS viii INTRODUCTION 1 I. ABIOTIC COMPONENTS 7 Introduction 7 Annual Discharge 9 Depletions 9 Irrigation Use 11 Transmountain Exports 12 Reservoir Evaporation 14 Other Uses 17 Analyses of Historic Records 18 Salinity 28 Sediment 29 Temperature 32 pH 33 Dissolved Oxygen 34 Other Water Quality Parameters 35 II. BIOLOGICAL COMPONENTS 42 Introduction 42 Primary Producers 42 Invertebrates 44 Fishes 45 III. SPECIES DESCRIPTIONS 47 Introduction 47 Colorado Squawfish 54 Humpback Chub 61 Razorback Sucker 65 Bonytail Chub 70 Colorado River Cutthroat Trout 74 Kendall Warm Springs Dace 80 Roundtail Chub 82 Piute Sculpin 86 Mottled Sculpin 87 Flannelmouth Sucker 88 Mountain Whitefish 90 Speckled Dace 91 Mountain Sucker 92 Bluehead Sucker 93 iii IV. RIVER BASIN DESCRIPTIONS 94 Yampa River Basin 96 Green River Basin 103 White River Basin 111 Upper Colorado River Basin 116 San Juan River Basin 123 Dolores River Basin 129 Gunnison River Basin 132 V. MAJOR FACTORS INDUCING ENVIRONMENTAL CHANGE 137 Livestock Grazing 137 Parasites and Diseases 140 Dams 141 Introduced Fish Species 144 Hybridization 147 Industrial and Municipal Pollution 151 Logging 152 Water Depletions and Flow Requirements 154 VI. URGENT NEEDS AND RECOMMENDED RESEARCH PRIORITIES 156 LITERATURE CITED 163 APPENDIX A 174 iv LIST OF TABLES Page Table 1.1 Water Budget for the Upper Colorado River Basin, 1975 (Figures computed from U.S. Water Resources Council, 1976). Table 1.2 Water uses by hydrologic subregions, 1975, Upper Colorado River. Table 1.3 Main stem reservoirs of the Upper Colorado River Basin and their initial storage dates, contents for September, 1975 and annual evaporative losses for 1975 (U.S. Department of Interior, 1977: U.S. Geological Survey, 1975). LIST OF FIGURES Figure 1.1 The upper Colorado River Basin and its three hydro- logic subregions Figure 1.2 Annual discharge and depletion of the upper Colo- rado River at Lee's Ferry, Arizona (Data from the Bureau of Reclamation, Salt Lake City, Utah, 1977.) Figure 1.3 Water exported from the three hydrologic subregions of the upper Colorado River basin via transmountain diversions (1914-57) from Iorns, et al. 1965; the remainder from Upper Colorado Region State - Federal Inter-Agency Group, 1971; U.S. Water Resources Council, 1976. Figure 1.4 Five year averages of monthly flow of the Yampa River at Maybell, Colorado, water years 1917 to 1974. Figure 1.5 Five year averages of monthly flow of the White River at Watson, Utah, water years 1924-1977. Figure 1.6 Five year averages of monthly flow of the San Juan River at Bluff, Utah, water years 1915-1977. Figure 1.7 Five year averages of monthly flow of the Gunnison River at Grand Junction, Colorado, water years 1897- 1974. Figure 1.8 Five year averages of monthly flow of the Colorado River at Cisco, Utah, water years 1914-1977. Figure 1.9 Five year averages of monthly flow of the Green River at Green River, Utah, water years 1897-1977. Figure 1.10 Five year average May depletions in four upper Colorado basin rivers. vi PREFACE The upper Colorado River system has become the focus of much concern. The presence of endemic species and their threatened and endangered status, coupled with a manifest pressure to reduce the already over-allocated water resources for additional agricultural, domestic, mining and industrial uses, and for the development of some of the largest fuel deposits (coal, oil, oil shale, uranium) in the United States, has produced a situation of potential conflict between develop- ment and environmental maintenance. There exists today a significant amount of information concerning many aspects of the upper Colorado River ecosystem. This large basin encompasses more than 109,000 square miles and has a unique resident fish population, for more than two-thirds of the native fish are endemic. This document represents part two of a more comprehensive three-part study of the status, life history, and habitat requirements of endan- gered and threatened fishes of the upper Colorado River system. The complete report consists of the following: Part 1 - An Indexed, Annotated Bibliography of the Endangered and Threatened Fishes of the Upper Colorado River System. Part 2 - An Evaluation of the Status, Life History, and Habitat Requirements of the Endangered and Threatened Fishes of the Upper Colorado River System. Part 3 - Detailed Distribution Maps, Keyed to the Literature, of Endangered and Threatened Fishes of the Upper Colorado River System. This report (part two) is an evaluation of the status, life history, and habitat requirements of the threatened and endangered fishes of the upper Colorado River system. The focus is, of course, the threatened and endangered fishes of the upper Colorado River system; and a full appreciation would not be possible without an adequate knowledge and familarity with the ecosystems in which they live and reproduce. This report attempts to present the total picture of both the endangered fishes and the upper Colorado River system. The report is organized vii into six major sections. A brief description of each section is pre- sented below to enable the reader to move directly into those areas of particular interest. Section I. Abiotic Components Changes in water quantity and quality represent one of the major reasons for the population decline of many fish species. This section deals with physical and chemical aspects of the Colorado River system which directly affect the well being of its fishes. Section II. Biological Components This section represents a brief description of the biological components of the Colorado River, the role each plays in the environment, and their relationship to the important fishes. Section III. Species description This section presents a detailed discussion of the threatened and endangered fishes of the Colorado River as well as other important fishes of the system. Past and present distribution of each species and their life history are described in as much detail as the literature would allow. This section contains the most inclu- sive discussion of the fishes dealt with in the report. A dis- cussion of speciation introduces the section. Section IV. River Basin Descriptions The focus of this section is on the major sub-basins that comprise the upper Colorado River drainage basin. The history and character of each basin are described in detail as is the distribution of fishes within each. Section V. Major Factors Inducing Environmental Change This section is a general discussion of those factors that have brought about declines or alterations in the population of the endemic fishes of the upper Colorado River system. Mechanics of their effects are discussed as well as the results. Section VI. Urgent Needs and Recommended Research Priorities This section summarizes what the authors feel are the important issues which need to be answered concerning the status of viii endangered and threatened fishes of the upper Colorado River system. Areas which need to be mitigated are identified as are the recommended research methods. This report represents the efforts of a number of individuals including known experts in the field of endangered and threatened fishes of the upper Colorado River system (see acknowledgments). It is impor- tant to note, however, that the contents of this report do not neces- sarily reflect a consensus of all authors and/or co-authors. It should also be mentioned that, because of the sensitive subject matter, this report is based on factual data whenever possible; due to the lack of a comprehensive data base and the limits placed on the existing literature, speculation and professional opinion represent a significant part of the conclusions. It is the feeling of the authors that without this specu- lation and professional judgment the report would be incomplete. Obviously the reliability of projections of future situations based on sometimes realistic, sometimes nebulous assumptions is always open to debate. A great degree of effort has been expended in trying to view each situation as realistically as possible and to avoid emotional or non-professional interpretations. ix ACKNOWLEDGMENTS We wish to acknowledge the contributions of those individuals who assisted in this study. Dr. Robert J. Behnke of Colorado State University provided his exceptional expertise concerning status and overall ecology of the warm and cold water fishes of the upper Colorado River system. Dr. Behnke also was instrumental in technical editing. Dr. Paul B. Holden was a key contributor in assessing the status of warm water fishes of this system. These individuals were instrumental to this study in providing insight and professional judgments; their contributions were critical. We also feel it is appropriate to extend our appreciation to the U. S. Department of the Interior, Office of Biological Services, Fish and Wildlife Service, Western Energy and Land Use Team, for identifying the need and allowing us to undertake such an important study, and particularly to Dr.