|
<br />Wetlands hold promise for raising endangered fish
<br />
<br />[~:;rj~?i.;~~S.~~~~"~--,: :',--:~~"- -~;;~ ',-~.",~l
<br />"-"',hk"'~"',,~~lJ:ID.{@k~:,. ',..'...';" "
<br />!:/~:~'~.'~,~~.~~\1i~;~~.\\~~,~::i
<br />t:::~~~~~j(J'~I~~~' ". ',' ':>'" '. :.1.
<br />~';',?Z~:;'.>,:_?V:)~~;~~l",:;'~~;~,' " ~_h""" ',..:
<br />('~ '., ,f','~.>J~'~~~@,":. "~~~l: ""1
<br />': ,'", ,,' '\illf'~.. ," ~r,w,::i@1Ul
<br />I ,,' "', ''''ii~f1iur!@ :m> l~I}"JIl:J~:;il
<br />r ....'.. r.'",.. .r:-:: _:- .: :..,,: " , _ ~ ': ":" .' _', .;
<br />!' {@;1ll,"~~_.j;~JI1,~; ''-~'J1 . "i1;~[i!LollWI&:"lfu,~:";~iJ%~(@;\\,~~~"~,~~."iJ;ill"~I~i;
<br />! 11i!i;r,1!ti. ~"!i)'lI;i)l;Sl\!t1ffi'IN,,,~I1);f~l,l. ,,' , .~. '.;
<br />L_~~~:..:.:,:"~.:":':"~__'~,~,,, ..'.~.~'-:-L :_:.:' ::"'-c_ _ ~~:":il......JW.; "':~:. c'J
<br />
<br />Warmer water" more food
<br />
<br />h,elps young fish grow
<br />
<br />Biologists collected' 28 4- to 5-,
<br />month old endangered razorback suck-
<br />ers in a Utah wetland last fall- more
<br />than researchers have found in any pre-
<br />, vious study. .
<br />Although old adult razorbacks exist
<br />in the Green River, the discovery eiC
<br />these young', fish, in a wetland' ,on the
<br />Ouray National Wildlife .Refuge has
<br />proved that razorbacks can survive
<br />beyond the critical stage in the wild.
<br />"Most fish die' during the first few pants hope 'to, help razorback suckers
<br />months of Iife,','said, U.S. Fish and'" rebound' from the brink of extinction.
<br />Wildlife Service biologist Tim Modde. this approach also could inadvertently
<br />"If they get past that stage, they have a . improve conditions for many other
<br />much better probability of survival." .. species of wildlife. "",. " "
<br />The last time biologists found wild "Wetlands, 'in general, produce'
<br />razorbacks of that age ,was iri 1965, , greater quantities of 'biomass' (plant
<br />when' they, discovered eight, of these and animal matenal) than any other
<br />fish after Flaming Gorge Dam had been, habitat type on the face of the Earth _ '
<br />, completed: (ConSll:Uction of dams and more so than the rain forests of Brazil,'"
<br />subsequent introductions 'of non-native 'said Chuck Elliott, who oversees a
<br />species are the two pflmary reasons regional, wetlands ,inventory for. the"
<br />these fish now are endangered.) , Fish and Wildlife Service. '
<br />"This new' finding doesn't mean ,'John Hamill, whodifects themulti-
<br />recovery is at hand; but it has taken a agency Rec~very Program agrees. '
<br />major step forward," Modde said. It '''In the arid West, the' majority of
<br />also demonstrates the need to make ' birds; amphibians, maininals and other
<br />similar' wetlands' available tD '. other "species are cODcentrated in riverine cor-
<br />young endangered fish, he explamed: , ridors. They're there because of wetland
<br />, habitats,'~ Hamill said. "These areas are
<br />, 'rich.and productive, and to the. extent
<br />, that we can restore them for endangered
<br />fish; many other species will benefit.';
<br />Today an estimated 500 adult razor- '
<br />, backs live in the river basin., Native to
<br />" the Green, Colorado, Gunnison, Yampa '
<br />'. and White rivers, razorback, suckers'
<br />began to disappear once Flaming
<br />Gorge and other dams were built.
<br />Along the Green River; the con-
<br />. ,structionof Flaming Gorge harnessed
<br />, the river's seasonal flows. Spring and
<br />early summer wetlands that ,once
<br />, served ~s the nlzorback's rearing' and
<br />feeding grounds vanished. In addition;
<br />introductions ,of ilOn-native, fish such
<br />, ,as carp, nOI1hem pike" fathead miri-
<br />
<br />'Wetlands produce greater:
<br />quantities oj .'biomass ' than any
<br />a/her habitat type on the face of
<br />the Eqrth'- more so than the
<br />rain forests of Brtizil.' '
<br />
<br />'-:- Chuck Elliot
<br />
<br />To accomplish that,. biologists with
<br />the Recovery,Program for Endangered
<br />Fish of the Upper Colorado River
<br />Basin are 'trYing to imprqve eridan~
<br />gered fish habitat by allowing the
<br />basin's rivers t6 flood s'ome botto'm
<br />lands much as they did before dams,
<br />were built. By restoring these seasonal
<br />wetlands, Recovery Program partici-
<br />
<br />6
<br />
<br />nows and red shiners inc~eased the,
<br />number of rilzorbilck predators.'
<br />" Now biologists are working to miti-
<br />gate those impacts by increasing flows
<br />from the dams, and by creating open-
<br />ingsjn:'downstream dikes, levees and
<br />dive'rsions to re-establish the seasonal, '
<br />, wetlands that once' enabled ,the nizor-
<br />backs to flourish. ," ,
<br />"We'~e fairly optimistic that we'll '
<br />be able to' restore a, sufficient amount
<br />of habitat to recover the species,'.' said
<br />Pat Nelson, who coordinates the flood
<br />plain ' restoration' work for .the
<br />Recovery Program. ,
<br />While the river basin 'encompasses
<br />871 river' miles, ReC!lVery Program
<br />officials are not trying to reclaim all
<br />'natUral wetlands that once e"isted. A
<br />survey of the Green and Colorado river
<br />'drainages identified 135 sites in the
<br />. Green River drainage and 158 through-
<br />out the Colorado River drainage ,that
<br />'possibly could provide good habitat: .
<br />Those 293 sites then wcreassessed
<br />in ~elation to land ownership and prox-
<br />imity to razorback spawning grounds'
<br />and tei adult, raZorback habitats. Also'
<br />considered was whether the wetland
<br />was connected to' the river during
<br />spring - when larval razorbacks hatch
<br />and enter the river -and the potential
<br />that .the' site could 'be connected', to
<br />, other nearby flood plains.
<br />, Whether all sites "";ill be restored
<br />depends on further review by Recovery
<br />
<br />See WETLANDS Page 7.
<br />
|