Laserfiche WebLink
<br />~ <br /> <br />~ <br /> <br />No.: <br /> <br />d--5 <br />(for MC use) <br /> <br />RECOVERY J:MPLEMENTATJ:ON PROGRAM <br />FOR ~ ENDANGERED FJ:SB SPECJ:BS <br />J:N ~ UPPER COLORADO RJ:VER BASJ:N <br /> <br />FY-1992 <br />SCOPE-OF-WORK <br />RESEARCH PROPOSAL <br /> <br />Phone: <br />Date: <br /> <br />Utah Wildlife Resources <br />Leo Lentsch <br />1596 West North Temple. <br />Salt Lake citv. UT B4116 <br />IBOll 53B-4756 <br />Mav 14. 1991 <br /> <br />Cateaorv Icheck onel: <br />ongoing project <br />X Requested Dew start <br />Unsolicited project <br />Outside funding <br /> <br />Lead Agency: <br />Submitted by: <br />Address: <br /> <br />I. Title of Proposal: <br /> <br />Aspinal Studies: Flow Effects on Humpback Chub Populations in Westwater <br />and Black Rocks Canyons <br /> <br />II. Relationship to Recovery Program/Ranking Factors: <br /> <br />This study will be conducted cooperatively by Utah Division of Wildlife <br />Resources (UDWR), U.S. Fish and Wildlife Service (FWS), BIO/WEST, Inc., <br />and Larval Fish Laboratory (LFL) as part of the studies to assess the <br />opportunities to re-regulate the Aspinal Unit to benefit endangered fishes <br />in the Gunnison and Colorado rivers. The study focuses on the Westwater <br />Canyon and Black Rocks populations of humpback chubs in the Colorado River <br />40 to 50 miles below the Gunnison River confluence. It is designed to <br />specifically address the effect of high spring flows on successful <br />reproduction and recruitment of humpback chub, as well as the effect of <br />seasonal flow events on the formation of critical habitat and the <br />invasion/proliferation of non-native species. The study will also assess <br />the effects of flows on the invasion of roundtail chubs into Westwater <br />Canyon and Black Rocks and the potential impact of hybridization. <br /> <br />III. Study Goals, Objectives, End Product: <br /> <br />The goal of this investigation is to develop flow recommendations for the <br />Colorado River to protect spawning and nursery habitat of humpback chub in <br />Westwater Canyon and Black Rocks. Currently, there are no flow <br />recommendations for humpback chub in the upper basin. Maintenance of the <br />populations in these areas is vital since these areas support the largest <br />numbers of the species in the upper basin. The objectives of the study <br />are to: (1) Determine spawning and nursery requirements, (2) Determine the <br />extent of larval drift, (3) Identify and describe reproductive isolating <br />mechanisms, and (4) Assess recruitment. The end product will be flow <br />recommendations for spawning and nursery habitat as well as recruitment of <br />humpback chub in Westwater Canyon and Black Rocks. <br /> <br />IV. Study area: <br /> <br />The study area is a 13-km reach of the upper Colorado River (BM 116 -124) <br />within Westwater Canyon, Utah, and a 1.6-km reach (BM 135.6 - 136.6) in <br />Black Rocks, Colorado. <br /> <br />V. Study Methods/Approach: See attachment <br /> <br />VI. Task Description (FY-1992): See attachment <br />