WSP04426 - Laserfiche WebLink

Home Browse Search

6578 Federal Register ,'Vz:jS8, No, 18 , Friday. January 29, "993 ,-)ropoSad Rules - DEPARTMENT OF THE INTERIOR Fish and Wlldllle Service 50 CFR Part 17 RIN 1018-AB91 Endangered ancl Threatened Wildlife and Planta: Proposed Determination 01 Crllleel Habitat lor the Colorado River Endangered Flahea: Razorback Sucker, Coloredo Squewtleh, Humpbeck Chub, and Bonytell Chub AGENCY: Fish and Wildlife Service, Interior. ACTION: Proposed rule, SUMMARY: The Fish and Wildlife Service (Service! proposes to designate critical habitat for four species of endemic Colorado River Basin fishes: Razorback sucker (Xyrnuchen texanusl. Colorado squawfish (Ptychocheilus lucius), humpback chub (Gila cypha), end bonl~ail chub (Gila e/egans). These species are listed es endangeied under the Endangered Species Act (Act) of 1973, as amended (16 U,S,C, 1531 et seq,), Historically, these four species occurred throughout the Colorado River system from Wyoming to Mexico, The Service is under court order to publish a proposed rule for critical habitat for the razorback sucker by January 25, 1993, usiag presently available information. Tha Service proposes to designeta a total of 3,370 kilometers (2,094 miles) of critical habitat for the four Colorado River endangered fishes, There is considerable overlap in areas designated for the four species, The designation for all four species includes portions of Colorado, Utah, New Maxico, Arizona. Nevada, and California, The Service proposes 2,935 kilometers (1,824 milesl of critical habitat for the razorbad: sucker (52 percent 0/ its historical range); ),843 kilometers (1,148 miles) for the Colorado squaw fish (29 percent of the historical range): 610 kilometers (379 miles] for the humpback chub (28 percent o/the,historical ranga); and 544 kilometers (344 miles) for the bonytBll chub (13 percent of the historical range). This proposed critical habitat designation. when made final, would result in additional consultation and conference requirements under section 7 of the Act with regard to Federal agency actions which are likely to destrov or adversely modify critical habitat. The Service is soliciting data and comments /rom the public on all aspects of this proposal. including information on the impacts and benefits oftha designation. OATES: Comments on this proposed rule will be accepted untii March 30, 1993, AOORESSES: Infonnation, comments. or questions conceming this proposed rule may be submilled to the Utah State Supervisor, Ecological Services, U,S, Fish and Wildlife Service, 2060 Administration Building, 1745 West, 1700 South, Selt Lake City, Utah 84104, The complete file for this rule is available for public inspection, hy appointment, dUring nonnel busin..s hours et the above eddress, FOR FURTMER INFORMATION CONTACT: Robert D, Williams, Utah State Supervisor, at the above address, telephone 801/975-3630, SUPPLEMENTARY INFORMATION: The Fish and Wildlife Servica (Service) has had limited time to prepare a proposed rule, Because of this. an economic analysis. B biological support document, and a complete evaluation of the effects of the critical habitat designation are not now available, The economic enalysis and a hiological support document ere cw;rently in preparation, Once completed, e notice will be published in the federal Register, announcing their availability and the dates and locations of public hearings, A comment period will/allow publication of the documents: this will allow public review of the economic analysis and the biological support document, The Service will hold public hearings on this proposed rule in Phoenix, Arizone: Denver, Colorado: and a site to be detennined in southern Californie, The dates and specific locations for these hearings will be published in the Federal Register at least 15 days prior to the first hearing. Any detenninations on exclusions of areas proposed as critical habitat will be published in the final rule, The biological support document will contain detailed discussion 0/ the process used to select critical habitat reaches, This will include a summary of known life history and ecological requirements for these species. presentation of the infonnation used to develop the primary constituent elements, and a discussion of the biologicial basis for selection of proposed river reaches, Additionally, a discussion of activities which affect or may be affected by critical habitat designation will be included, The economic analysis will contain an evaluation of costs and benefits resulting from this proposed designation. The information that will 06 contained in the economic analysis are detailed under the "Considerations of Economic and Other Factors" section within this document. The economic analysis will be used by the Service during the exclusion prosess, The exclusion process will detennine whether the benefits 0/ such exclusion outweigh the benefits of specifying such area as pert of the critical habitat unlesa it ia determined that the failure to designate such area as critical habitat will result in the extinction of the species concerned. Background The Colorado River Basin (Basin) encompasses portions of seven Western States, The Upper Basin consists 0/ portions of the States of Colorado, New Mexico. Utah, and Wyoming, Tha Lower Basin consists of portions of the States of Arizona, California, and Nevada, The Basin drains epproximately 627,000 square kilometers (242,000 square miles) within the United States, An additional 5,000 square kilometars (2,000 square miles) of the Basin lies within Mexico. Historically, the native fish fauna of the mainstream Colorado River was dominated by native minnow. (cyprinids) and suckers (catostornids; Minckley et al, 1986), However, four of these, the razorback sucker (Xyrnuchen texonus), Colorado squawfish (Ptychochellus lucius), humpback chub (Gila cypha), and bonytail chub (Gila degans), are now listed as endangered specie., These fishes are threatened with extinction due to the combined effects of habitat loss (including regulation of natural flow, temperature, and sediment regimes); proliferation of introduced fishes; and other man- induced disturbances (Miller 1961; Minckley 1973; U,S, Fish and Wlldlifa Service (USfWS) 1987; Carlson and Muta 1989), Native Colorado squawfish stocks survive only in the Upper Basin, where lbeir numbers are relatively high only in the Green River basin oCUtah and Colorado (Trus 1991), Razorback sucker and bonytail chub steeks consist predominately of old adult fish, and they remain only because 0/ the longevity inherent in these species (USFWS 19900: Minckley et al. 1991), Humpback chub populations in the Little Colorado River and at Black Rocks in tha Colorado River appear relatively stable in number of fish, but declines have been apparent in other locations (USFWS 1990b). Conservation of these four species will require the identification and management of water resources and habitat areas that are considered important to any fish species, such as spawning areas and nursery grounds, However, because the four endangered fishes are present in such low numbers.