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<br />: qolorado River endangered fish
<br />
<br />
<br />Colorado squawfish (Ptychocheilus lucius)
<br />North America's largest minnow, Colorado
<br />squawrish once grew to nearly 6 reet long and were
<br />called "white salmon" or "Colorado salmon" by
<br />early sClllers. HislUrically, these voracious predators
<br />dominated the Colorado River system.
<br />
<br />Razorback sucker (Xyrauchen texanus)
<br />Razorback suckers can grow 10 more than 3 feet
<br />and are one of the largesl suckers in Norlh America.
<br />Few if any young razorbacks are left in the wild.
<br />
<br />Bony tail chub (Gila elegans)
<br />Bony tail chubs can grow to 24 inches or more
<br />ami can live nearly 50 years. Wild bony tails are
<br />nearly extinct.
<br />
<br />Humpback chub (Gila cypha)
<br />The pronounced hump behind its head gives Ihe
<br />humpback chub a striking, unusual appearance. This
<br />minnow can grow to nearly 20 inches and may
<br />survive more Ihan 30 years.
<br />
<br />~' -~~ ) COlORADO
<br />SOUAWFISH
<br />I
<br />, ,
<br />MuullllU It'df or t!~t.'
<br />
<br />~
<br />1'1
<br />I . . ROUNDT All
<br />I CHUB
<br />I
<br />, ,
<br />Maulll {)(Ily 10 IrOnl 01 I:lyt'
<br />
<br />An!:lers ilia)' ((Inl'use YlIIlIl!: Cnluradn slluawlhh with
<br />rnundlail dlllhs. The ke}' Ilill'erence is Ihal the ruundtail's
<br />mnuth estl'IHh just In the I'runt ul' the e}'e. The snuul IIl'the
<br />s/IU;l\Ilish b lunger, ,lIld its lhkk fulded lips extcnd tn the
<br />rear III' thc c)'c.
<br />
<br />The Colorado River
<br />
<br />The Colorado and its tributaries make up one 01'
<br />Ihe world's most colorrul river systems. From the
<br />high mounlains of Wyoming and Colorado, (he river
<br />drops more lhan two miles in elevation on a 1,700-
<br />mile journey 10 Ihe GuH 01' Calirornia. For long
<br />stretches, the river system is bounded by red canyon
<br />walls. Flows flucluate widely from season 10 season
<br />and year to year. For example, historic nows at
<br />Yuma, Ariz., ranged from a few thousand cuhic feet
<br />per second to nearly 400,000. It took tough,
<br />adaptable crealures 10 survive in this river system.
<br />
<br />Endangered fish distribution map
<br />
<br />
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<br />- ~-------'
<br />
<br />Once ,Ihundanl in the Culunlllu l{iVl'r Basin, these Ii~h
<br />nuw are fuund nnly in certain purtiun~ uf ~UlllC ri\'cl'~.
<br />
<br />Release them alive
<br />
<br />If you calch any fish you cannot identify, please
<br />return it to the water alive. If possible, leave the fish
<br />in the water while genlly removing Ihe hook. Do not
<br />squeeze the fish or put your fingers in its gills. If the
<br />hook is deeply embedded, cut the line instead of
<br />pulling out the hook. Hold the fish facing upstream
<br />and slowly move il forward and back in the water.
<br />Then release the fish in quicl water.
<br />If the fish is tagged, please report the tag number
<br />and color 10 Ihe Colorado Division of Wildlife, (303)
<br />248-7175, or Utah Division of Wildlife Resources,
<br />(801) 538-4700. Fines up to $/00,000 are possible
<br />for willfully destroying endangered fish.
<br />
<br />Why are these fish endangered?
<br />
<br />Water
<br />development
<br />Dams and
<br />canals have
<br />been con-
<br />structed
<br />'.,. throughout
<br />the Colorado
<br />River Basin
<br />to provide
<br />water for power, irrigation and public water supplies.
<br />These water projects have restricted the fish to about
<br />25 percent of their range, blocked some spawning
<br />migralion routes and cooled Ihe water immediately
<br />downstream of Ihe dams. Also, many of Ihe rivers'
<br />"backwaters" needed by young fish have disappeared.
<br />
<br />
<br />Non-native
<br />fish
<br />SpOI'l and
<br />bait (ish have
<br />been intro-
<br />duced into
<br />nvers, lakes
<br />and reser-
<br />voirs. Non-
<br />nalive fish
<br />compete with native fish for food and space and may
<br />prey on Ihe eggs and young of endangered fish. The 14
<br />nalive Colorado River fish now have to compete with
<br />more than 40 non-native species.
<br />Rainbow, brown and cutthroat trout are still
<br />slocked in higher elevations of the Colorado Riwr
<br />and its tributaries. Trout prefer colder waters and arc
<br />not considered competitors with endangered lish.
<br />
<br />
<br />Other factors
<br />Some native fish may be killed accidenlally by
<br />anglers. And in the mid-1960s, the chemical rotenone
<br />was used in portions of the upper Colorado River
<br />Basin to reduce native lish numbers and make way ror
<br />non-native sport fish. SuI researchers believe this had
<br />no lasling effect Oil native fish populalions.
<br />Other possible problems include pollution nnd
<br />parasites, and among chubs, hybridization.
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