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<br /> <br />000771 <br /> <br />The u.s. Fish and Wildlife <br />Service has designated four <br />different species of fish <br />native to the Colorado River <br />as endangered: Colorado <br />squawfish, razorback sucker, <br />bonytail chub and humpback <br />chub. These fish once were <br />plentiful in the Colorado <br />and its tributaries. However, <br />their numbers have declined <br />dramatically. Listing a. <br />species as endangered indi- <br />cates that the organism is <br />facing extinction in the wild. <br />A<;lditionally, listing provides <br />legal protection from man- <br />caused killing or removal, <br />except in specifically permit- <br />ted circumstances. This pro- <br />tection typically represents <br />additional regulatory require- <br />ments for development of <br />new or operation of existing <br />facilities. <br />The Colorado squawfish <br />is North America'S largest <br />minnow. These fish once <br />grew to lengths of six feet <br />and reached weights of 80 <br />pounds. Ii was the top <br />predator in the Colorado <br />River system. Though the <br />squawfish's diet consists pri- <br />marily of other fish, fisher' <br />men caught them in earlier <br />times by using mice, small <br />birds and even prairie dogs. <br />Once Colorado squawfish <br />were so abundant that they <br />were fished commercially. <br />The razorback sucker is <br />one of the largest suckers in <br />North America. Named for <br />the characteristic keel-edged <br />hump just behind its head, <br />it can grow to more than 13 <br />pounds and reach lengths of <br /> <br /> <br />I <br /> <br />three feet or greater. Once <br />widespread throughout <br />most of the Colorado River <br />Basin from Wyoming to . <br />Mexico, its current range <br />is limited and spotty. <br />The bony tail chub also is <br />a member of the minnow <br />family. With large fins and <br />a streamlined body, the <br />bony tail is the rarest of the <br />four endangered fish. It is <br />nearly extinct; no repro- <br />ducing wild populations <br />are known. Some bonytail <br />have been captured and <br />are held for breeding stock. <br />The humpback chub is <br />so named because of the <br />.ptominent hump behind <br />. its head. They can grow to <br />. 30 inches and may survive <br />more than 30 years in the <br />wild: A population of <br />about 10,000 humpback <br />exist in the Little Colorado <br />River of the Grand Canyon. <br />Smaller numbers are found <br />in the upper Colorado'River. . <br />The squawfish arid razor- <br />back sucker evolved more <br />than 3 million years ago- <br />truly earning them title of <br />"native. " <br />These four fish species <br />have been impacted by <br />several outside influences. <br />Introduced uon'native <br />fish, such as pike, catfish <br />and red shiners, proved <br />superior competitors to <br />the detriment of these <br />native fish. Water develop- <br />ment and use have altered <br />seasonal flow patterns and <br />lowered temperatures, as <br />well as created physical <br />barriers to historic migra- <br />tion patterns. In the mid- <br />1960s, stream segments <br />were poisoned to limit <br />native fish populations and <br /> <br />to prepare for the intro- <br />duction of sport fish. Other <br />factors which may have <br />contributed to the historic <br />decline include pollution <br />and parasites. Among the <br />chubs, hybridization also <br />may be afactor. <br /> <br />CRITICAL HABITAT <br />DESIGNAtIONS <br />Previously thought only to <br />be an upper basin issue, in . <br />March of 1994 critical habi- . <br />tat for these fish were des- <br />ignated by the U.S. Fish <br />and Wildlife Service, and <br />large portions of both the <br />upper and lower basins <br />were included. <br />In the lower basin, the <br />service designated the <br />Colorado River from Lee <br />Ferry to Davis Dam, <br />including lakes Mead and <br />Mohave, and from Parker <br />Dam to Imperial Dam as <br />. critical habitat for. the <br />razorback sucklOr. <br />Stretches "fthe river <br />. from Hoover Dain to <br />Davis Dam, including Lake <br />Mohave, and from the <br />northern boundary of the <br />Havasu National Wildlife <br />Refuge to Parker Dam, <br />including Lake Havasu, <br />were designated as critical <br />habitat for the bony tail <br />chub. A number of tribu- <br />tary reaches were designat- <br />ed as welL <br />Finally, a reach of the <br />Colorado in the Grand <br />Canyon was designated <br />as critical habitat for the <br />humpback chub. <br />In the upper basin, the <br />cumulative designation <br />essentially extends <br /> <br />throughout most of the <br />basin, as specific designat- <br />ed habitats for the various <br />four fish overlap in some <br />cas!,s and 'are distinctand <br />separate in others. <br />In general, the total des- <br />ignated habitats are: The <br />Colorado upstream from <br />Lake Powell to the conflu- <br />ences.ofthe Gunnison and <br />the Green; the Colorado <br />continuing upstream to <br />about Rifle, Colorado; the <br />Green upstream to the <br />confluence with the Yampa: <br />and then continuing up the <br />Yampa to about Craig, <br />Colorado; the White from <br />the confluence with the <br />Green upstream to Rio <br />Blanco Reservoir in <br />Colorado; and the <br />Gunnison upstream to <br />the confluence with. the . <br />Uncompahgre near Delta, <br />. Colorado. In addition, the <br />San Juan has been desig: <br />nated from Lake. Powelf . <br />upstream to about <br />Farmington, New Mexico. <br />Within the upper basin, <br />Utah contains the most' <br />critical habitat, followed <br />by Colorado and New <br />Mexico. <br />Before issuing its rule, <br />the service received some <br />400 comments either in <br />writing or verbally in <br />response to review of its <br />nearly 600-page economic <br />analysis document. <br />Additionally, it analyzed <br />whether its actions would <br />interfere with constitution- <br />ally protected property <br /> <br /> <br />;" <br /> <br />If /' <br />'.... :.......:>.' <br />.-,- :::-~ <br />, .-~hl <br />'.. V~ <br />',' :-"1 <br />-., <br /> <br />;.._\-c./" <br /> <br />