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<br />Stocking to boost' razorback sucker numbers
<br />
<br />RAZORBACKS, from 1
<br />
<br />Service biologist who works in Denver
<br />with the multi-agency Recovery
<br />Program for Endangered Fish of the
<br />Upper Colorado River Basin:
<br />The razorbackS placed in the Green'
<br />River were spawned in spring 1993
<br />and 1995 from 10 adult fish taken from
<br />the river and held in captivity at the
<br />Ouray Endangered Fish Hatchery near
<br />Vernal, Utah.
<br />Those stocked in the Gunnison were
<br />spawned iri 1994 from seven adult fish
<br />collected in the Colorado River and
<br />upper reaches of Lake 'Powell. They
<br />were raised at the Colorado Division of
<br />Wildlife's Bellvue ,Research' Hatchery
<br />near Fort Collins.
<br />The stocked fish were too large to '
<br />be eaten by red shiners, green sunfish'
<br />and most other non-native fish thought " slit; which allows them in, but prevents
<br />to prey on small endangered fish.' 'them from 'escaping.
<br />Biologists stocked more 'than 6,000' Using' this technique last year,
<br />razorbacks in the Green River in the researchers found about 200 'larval
<br />late 1980s and a handful of the fish in razorback suckers in the Grcen' River,
<br />the Gunnison River last year. Few of an encouraging, sign that proved razor- ,
<br />these fish have survived, leading the backs are reproducing. Now the biolo-
<br />scientists to conclude that' stocking gists are trying to learn, why so few
<br />alone will, not recover" the fish." young fish survive.to adulthood.
<br />However, researchers hope the ,trial To address the need for nursery habi-
<br />stocking will serve'as a, stopgap mea- tat, the Recovery Program has iriitiated
<br />sure to reverse the, decline of the fish. a 'flood plain habitat Iestoraiion' pro-
<br />Meanwhile, .they will continue work- gram. Participants are experimeniing'
<br />ing to re-create some, of the wetland, with ways to provide quality nursery
<br />habitats needed 'lS'''nursery,'' areasfor habitat for razorback suckers, without
<br />young fish., ' producing even greater nturibers of. the
<br />In the past 30 years,' researchers, non-native species that prey upon them.'
<br />have found very few juvenile or young 'On the', Green River the scientists
<br />adult razorbacks in the' wild. They 'have .restored an area known 'as "Old
<br />believe that many of the razorbacks . Charlie Wash" in Ouray National
<br />remaining, in' the Green River, 'were. Wildlife Refuge. .on the Coloni.do
<br />alive before Flaming Gorge Dam was River, researchers have also, restored
<br />completedin 1962. 'three flood plain sites: one on the
<br />Walter Walker StaieWildfife Area, one'
<br />near Adobe Cieek and one con 29 5/8
<br />, Road in Grand Juriction, Colo.
<br />"We are not trying to re-create the
<br />entire 'flood plain as it was 200: years
<br />ago," Nelson said. ''The goal is to restore
<br />natural flood plain functions necessary
<br />fOIrecovery of endangered fishes."
<br />
<br />Razorback reproduction studied
<br />To learn if the Green River fish
<br />were reproducing, biologists placed
<br />"light traps" in river backwaiers during
<br />the spawning season. At night, newly
<br />hatched larval fish' swim toward the'
<br />light and through a small funnel-like
<br />
<br />
<br />. '. . Photo by Sheila Pruitt
<br />Tom Pruitt, mamiger of the Ouray Endangere<! Fish Hatchery, and biDIDgieal
<br />technician Cathy Kaczmarek release 900 5-inch endangered razDrback suckers
<br />, into the Green River at Dinosaur National Monument. '
<br />
<br />During the process Nelson plans to
<br />keep area residents informed and
<br />, involved, possibly even working with
<br />private landowners to secure'conserva-
<br />. tiDn eas~ments. . .. . . .
<br />Area residents may want to take part
<br />in the habitat restoration program
<br />because of, benefits beyond aiding
<br />endangered fish. Flood plain habitat
<br />serves as seasonal. water storage areas,
<br />reducing .the threat of flooding down-
<br />, stream during' the "spring and then-
<br />releasing water during drier summer
<br />months. Wetlands also help replenish
<br />ground water supplies away from the
<br />river and trap and detoxify many natur-
<br />al 'and man-made pollutants. In addi- '
<br />tion, these" areas provide important
<br />, nesting and feeding habitat for. ducks,
<br />geese, songbirds and other wildlife.
<br />Of 14 fish speCies native to ihe
<br />upp'er Colorado River basin, four -
<br />the razorback sucker, bony tail chub,
<br />humpback. chub and Colorado squaw- '
<br />fish - are now on the federal endan-
<br />gered species list. In. the early 1900s,
<br />these fish were abundant and ,often
<br />, were "used for food by settlers.
<br />,'Biologists see the fishes' decline 'as an '
<br />indicator that the river ecosystem has
<br />changed dramatically. .
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