Briefing Paper to Accompany the Proposed Upper Colorado River and San Juan River Endangered Fish Recovery Act of 1997

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Colorado River endangered fish Colorado squawfish (Ptychocheilus lucius) North America's largest minnow, Colorado squawfish once grew to nearly 6 feet long and were called "white salmon" or "Colorado salmon" by early settlers. Historically, these voracious predators dominated the Colorado River system. Razorback sucker (Xyrauchen texanus) Razorback suckers can grow to more than 3 feet and are one of the largest suckers in North America. Few if any young razorbacks are left in the wild. Bonytail chub (Gila elegans) Bonytail chubs can grow to 24 inches or more and can live nearly 50 years. Wild bonytails are nearly extinct. Humpback chub (Gila cypha) The pronounced hump behind its head gives the humpback chub a striking, unusual appearance. This minnow can grow to nearly 20 inches and may survive more than 30 years. I I I C� ) COLORADO SQUAWFISH I I � Mouth to rear of eye I I I I - ROUNDTAIL I CHUB I I I Mouth only to front of eye Anglers may confuse young Colorado squawfish with roundtail chubs. The key difference is that the roundtail's mouth extends just to the front of the eye. The snout of the squawfish is longer, and its thick folded lips extend to the rear of the eye. 3 U Q. The Colorado River The Colorado and its tributaries make up one of x the world's most colorful river systems. From the m E high mountains of Wyoming and Colorado, the river r drops more than two miles in elevation on a 1,700- o 0 mile journey to the Gulf of California. For long oa stretches, the river system is bounded by red canyon 3 a walls. Flows fluctuate widely from season to season m and year to year. For example, historic flows at o m Yuma, Ariz., ranged from a few thousand cubic feet a m per second to nearly 400,000. It took tough, Scientific research has shown that losing one adaptable creatures to survive in this river system. species in an ecosystem can cause a chain reaction Endangered fish distribution map Feare�¢re Rock Springs LEGEND iramrne9 O¢¢e Rmer ocounlB orda ge-i¢M1 Reserrvar WYOMING Crag UTAH I n Gr¢e Mounraa an _ I OPAOOP Resertro�i en R. ceN I Gro 'A°rHi Rue EL 4 4 River Res¢rv0'r COLORADO Asp�naa Unrt I � roc I SCALE OF A LOMETERS ake Powelr Sr SCALE Or M I'S Lees ARIZONA I f Navaho Reservor NEW MExICo Ferry Once abundant in the Colorado River Basin, these fish now are found only in certain portions of some rivers. Release them alive If you catch any fish you cannot identify, please return it to the water alive. If possible, leave the fish in the water while gently removing the hook. Do not squeeze the fish or put your fingers in its gills. If the hook is deeply embedded, cut the line instead of pulling out the hook. Hold the fish facing upstream and slowly move it forward and back in the water. Then release the fish in quiet water. If the fish is tagged, please report the tag number and color to the Colorado Division of Wildlife, (303) 248 -7175, or Utah Division of Wildlife Resources, (801) 538 -4700. Fines up to $100,000 are possible for willfully destroying endangered fish. Why are these fish endangered? Water development Dams and canals have been con- structed throughout the Colorado River Basin to provide water for power, irrigation and public water supplies. These water projects have restricted the fish to about 25 percent of their range, blocked some spawning migration routes and cooled the water immediately downstream of the dams. Also, many of the rivers' "backwaters" needed by young fish have disappeared. Non - native fish Sport and bait fish have been intro- duced into rivers, lakes and reser- voirs. Non- native fish compete with native fish for food and space and may prey on the eggs and young of endangered fish. The 14 native Colorado River fish now have to compete with more than 40 non - native species. Rainbow, brown and cutthroat trout are still stocked in higher elevations of the Colorado River and its tributaries. Trout prefer colder waters and are not considered competitors with endangered fish. Other factors Some native fish may be killed accidentally by anglers. And in the mid- 1960s, the chemical rotenone was used in portions of the upper Colorado River Basin to reduce native fish numbers and make way for non - native sport fish. But researchers believe this had no lasting effect on native fish populations. Other possible problems include pollution and parasites, and among chubs, hybridization. Why should anyone care about saving endangered fish? Legal basis Because these fish are so rare, they are protected by state laws and the federal Endangered Species Act. In passing this act, Congress was reflecting the belief that rare species should be saved whenever possible. Environmental reasons Human impact has caused 40 species and subspecies of fish to go extinct in North America this century. Some biologists theorize that — like the coal - miner's canary, whose death forewarns workers of toxic gases underground — the decline of these fish may be a warning that other native species of the Colorado River ecosystem also are at risk. Heritage Colorado squawfish and razorback suckers evolved more than 3 million years ago. Modern man has existed only about 100,000 to 250,000 years. These fish are part of the West's heritage and are found nowhere else in the world. Philosophical reasons As Aldo Leopold, one of the founders of the conservation movement, said, " ... If the land mechanism as a whole is good, then every part is good, whether we understand it or not... " Sport- fishing m Until the early 1900s, squawfish were the Colorado River's top predator. Anglers were known to catch these fish using mice, birds and even small o rabbits as bait. If the fish can be recovered, tomorrow's anglers may gain the chance to reel in J Colorado squawfish weighing 15 to 20 pounds. B88 Ecosystem balance, scientific benefits aaa Scientific research has shown that losing one species in an ecosystem can cause a chain reaction affecting a series of other living things. Also, the species' unique genetic material and potential medical, industrial and agricultural benefits would be gone forever. Heritage Colorado squawfish and razorback suckers evolved more than 3 million years ago. Modern man has existed only about 100,000 to 250,000 years. These fish are part of the West's heritage and are found nowhere else in the world. Philosophical reasons As Aldo Leopold, one of the founders of the conservation movement, said, " ... If the land mechanism as a whole is good, then every part is good, whether we understand it or not... "