Mountain Sucker (Catostomus Platyrhynchus): a Technical Conservation Assessment
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Mountain Sucker (Catostomus platyrhynchus): A Technical Conservation Assessment Prepared for the USDA Forest Service, Rocky Mountain Region, Species Conservation Project August 23, 2006 Laura Thel Belica1 and Nathan P. Nibbelink, Ph.D.2 with a life cycle model by David McDonald, Ph.D.3 11623 Steele Street, Laramie, WY 82070 2University of Georgia, Warnell School of Forestry and Natural Resources, Green St / DW Brooks Drive, Athens, GA 30602-2152 3University of Wyoming, Department of Zoology, 1000 University Ave, Dept 3166, Laramie, WY 82071 Peer Review Administered by American Fisheries Society Belica, L.T. and N.P. Nibbelink. (2006, August 23). Mountain Sucker (Catostomus platyrhynchus): a technical conservation assessment. [Online]. USDA Forest Service, Rocky Mountain Region. Available: http:// www.fs.fed.us/r2/projects/scp/assessments/mountainsucker.pdf [date of access]. ACKNOWLEDGMENTS We thank the many biologists and managers from Colorado, Nebraska, South Dakota, and Wyoming and from the national forests within Region 2 who provided information about mountain sucker populations, status, and management in their jurisdictions. We also extend our appreciation to David B. McDonald at the University of Wyoming for the population demographic matrix analysis he provided. We especially thank Richard Vacirca and Gary Patton of the USDA Forest Service for their review of this species assessment and help in bringing this report to completion. We also thank Dr. Edward J. Peters, Professor Emeritus of the University of Nebraska-Lincoln and an anonymous reviewer for their comments and suggestions. AUTHORS’ BIOGRAPHIES Laura Thel Belica received her Master of Science Degree in Zoology and Physiology from the University of Wyoming in 2003 (as L. A. Thel). Her research interests center around the ecology of fishes, hydrology, and watershed management, especially as these are related to the management of aquatic ecosystems and native fishes. Nathan P. Nibbelink received an M.S. in Limnology and Oceanography from the University of Wisconsin- Madison and a Ph.D. in Zoology & Physiology from the University of Wyoming. He is currently an Assistant Professor at the University of Georgia’s Warnell School of Forestry and Natural Resources. His Ph.D. work focused on spatially explicit patterns in fish distributions in the Rocky Mountains. His current research focuses on the use of spatially explicit models for investigating the influence of landscape change on animal populations. COVER ILLUSTRATION CREDIT Mountain sucker (Catostomus platyrhynchus). Illustration by © Joseph Tomelleri. 2 3 SUMMARY OF KEY COMPONENTS FOR CONSERVATION OF THE MOUNTAIN SUCKER Status The mountain sucker (Catostomus platyrhynchus) is found throughout much of western North America, ranging from southern Canada in the north to Utah in the south, and from eastern California in the west to western South Dakota in the east. It is widely distributed in some parts of its range and sparsely distributed in others. In USDA Forest Service, Rocky Mountain Region (Region 2), the mountain sucker occurs throughout Wyoming and in northwestern Colorado and western South Dakota. Information regarding population trends of mountain sucker throughout its range is lacking, but the species appears to be stable in some regions while declining in others. Several state and federal agencies consider the mountain sucker to be a sensitive species, or species of concern, based on its rarity in some areas, apparent population declines, its sensitivity to further habitat loss, and the lack of knowledge of population trends at local and regional scales. Primary Threats The main threats to the mountain sucker generally result from anthropogenic activities, with geographically isolated populations or those that previous anthropogenic activities have adversely affected being the most susceptible to extirpation. Habitat loss due to stream impoundment has been the cause of mountain sucker population declines in some drainages, while habitat degradation from increased sedimentation has also contributed to observed declines in others. Construction of passage barriers, such as dams and culverts, results in population and habitat fragmentation, leaving populations vulnerable to extirpation. Although less well understood, the introduction of non-native fishes also appears to threaten mountain sucker populations, primarily through increased predation, but also via increased competition. Hybridization may be a concern for some populations, but little is known about hybridization between mountain sucker and other sucker species found in Region 2. In the past, fisheries management projects that have used piscicides to control unwanted species have posed a threat to mountain sucker populations. However current practices, which include efforts to salvage native non-game species, have reduced that threat within Region 2. Primary Conservation Elements, Management Implications and Considerations There is insufficient information regarding mountain sucker populations in Region 2 to identify population trends or to assess the impacts of particular land and water management activities on the species. Suggested priorities for conservation and management of the mountain sucker include better documentation of its occurrence in Region 2 and the initiation of long-term monitoring programs for select populations. Coordination with state and other federal agencies would be beneficial in efforts to update mountain sucker distributions at local levels in Region 2 and in establishing monitoring programs. Knowledge of mountain sucker habitat associations and movement patterns, especially dispersal and seasonal movements, is necessary for assessing the impacts of land and water management activities that could result in habitat loss, degradation, or fragmentation. The matrix demographic model suggested that mountain sucker population persistence is vulnerable to variations in survival rates, particularly of young age- classes, age-0 up to the age of female recruitment into the breeding population at around age-3 or age-4. Consequently, a better understanding is needed of mountain sucker habitat requirements, particularly for young and young adults, to understand population persistence in the long term. Considering the limited information available on the mountain sucker, conservation and management efforts should be directed to inventorying populations and maintaining stream habitat quality and connectivity where populations are known to occur on or downstream of National Forest System lands in Region 2. 2 3 TABLE OF CONTENTS ACKNOWLEDGMENTS ..............................................................................................................................................2 AUTHORS’ BIOGRAPHIES .........................................................................................................................................2 COVER ILLUSTRATION CREDIT ..............................................................................................................................2 SUMMARY OF KEY COMPONENTS FOR CONSERVATION OF THE MOUNTAIN SUCKER ...........................3 Status..........................................................................................................................................................................3 Primary Threats..........................................................................................................................................................3 Primary Conservation Elements, Management Implications and Considerations.....................................................3 LIST OF TABLES AND FIGURES ...............................................................................................................................6 INTRODUCTION ..........................................................................................................................................................7 Goal............................................................................................................................................................................7 Scope, Uncertainty, and Limitations ..........................................................................................................................7 Web Publication and Peer Review .............................................................................................................................7 MANAGEMENT STATUS AND NATURAL HISTORY .............................................................................................7 Management Status ....................................................................................................................................................7 Federal Endangered Species Act ...........................................................................................................................7 Natural Heritage Ranks .........................................................................................................................................7 USDA Forest Service ............................................................................................................................................8 Bureau of Land Management................................................................................................................................8 State agencies ........................................................................................................................................................8