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<br />1 'I/i
<br />
<br />TIL\N~. !\~ll':I:, FI.--lL ~o<:,' 1')("1, NO. :l
<br />
<br />ill the summer months and highe.f in the win.
<br />IeI' monlhs Ihall before impoulIl]mellL Dur.
<br />ing the 4. years since closure of the dam, the
<br />llegree of influence of the darn 011 downstream
<br />water temperatures has varied considerably
<br />(Figure 2; Table 2). In years of low sum-
<br />Iller discharge. JWj:~ and ]')65, sUlllmer waIPr
<br />temjJeratures at all Green Hiver locations
<br />from Bridgeport downstream to the Yampa
<br />River approximated pre.impoundment tem-
<br />peralures, Inyear8 of relatively high summer
<br />discharge, 1964 aud 1966" water temperatures
<br />\Ierc considerably below those of 196,3, 1965,
<br />and Ihe pre-impouJl(lment years as far down.
<br />stream as Island Park and Jensen (Figure 2;
<br />Table 2).
<br />Dissolved ox ygcn concentratiollS through-
<br />out the study area ranged from 6,4 to KS
<br />PIJlU. Tolal alkalinity, due largely to the
<br />prc"ence of hicarhonates, ranged from GS
<br />)lJ)llI al spring run.off to ]60 ppm ill Iale
<br />SlIlIImer, and pH ",dues ranged from 7,3 to
<br />:L6,
<br />Wain di"c1largl'd from Flaming CorgI'
<br />Danl lI'as clear and nearly sedilnent-frce, hut
<br />tributaries dOll'nstream discharged heavy silt
<br />load" inlo the riler during spring run.off and
<br />aftl'r Ill'avy sholl'ers, Turhidity lias highest
<br />lup 10 S.OOO ]ack.-on Turhidity {Jllils) during
<br />"pring rnn-off and gradually decreased 10
<br />11'''s Ihan Jon Ullits :IS summer progn's",'d
<br />and lIaln IeI'd receded,
<br />
<br />FISH D1STHWUTlON
<br />
<br />Coloraclo sfjllawfish were foullll hOIl! the
<br />moulh of Ule Yampa River. duwnslrealll to
<br />Ouray. This species had been collected be-
<br />tween Ihe Yampa mouth and the Flamin;,!;
<br />Gorge damsite before impoundment, holl'-
<br />el'er.5 Colorado chuhs were also common]\,
<br />fonnd from Ihe Yampa nlOnlh d'lwllslrea.:l
<br />lllrllll;!.h IIIl' ~lonlllllenl, and Wl're occasionally
<br />found al Lodore in the IHI'sent study. The;'
<br />had I"'('n present IlCtween th,. dalllsilc amI
<br />Lodon: before impollndment, bul were laken
<br />ahme Lodore only in 1963.
<br />""lilt "<IlIalVfi"l. wefe col/eded fro III pools,
<br />eddies, mHI runs, over various IIOLtolll types,
<br />and were taken with gill nets and lhe electric
<br />shocker. NOlll~ WRS found ill fasL water. ^dulL
<br />
<br />5 See {o"I/lole 4,
<br />
<br />::r-:64
<br />:L
<br />
<br />
<br />-----
<br />
<br />
<br />~30
<br />~
<br />
<br />1965
<br />
<br />70
<br />
<br />~60 ./' I
<br /><(50f ------:. ------1
<br />a:: . /-
<br />W .,' __-'
<br />Cl.40 . __'
<br />:::E -------
<br />
<br />w
<br />
<br />~::~~66' ~' . ... _E;~~p:A=~ I
<br />
<br />.' ._ISLAND PARK
<br />. .
<br />
<br />60r . .,.'- ----, ECHO PARK
<br />,-' .,- GREEN R.
<br />50' .. ,/
<br />
<br />
<br />:1> ~~- ,-_-~_-~ -~ -~~~:'~"=-I
<br />
<br />J F M A M J J A SON 0
<br />MONTH
<br />
<br />FU;I;BE 2. -1\/,."" w"ln 1""11"'1'11111'<" "t ("III Cr.,,,,,
<br />Hi,.., ,1"li",,_. ]f)(d.,l'J(,(,.
<br />
<br />Colorado chllbs lien: ~enerally found ill pools
<br />and eddies in the absence of, although oc-
<br />casiunally adjllCl'nt to, 8trong current, and
<br />gcnerally over silt or silt-boulder LoLlom
<br />types, These fish were taken by all types of
<br />C!ear, but gill nets were especially effective
<br />in capturing larger specimens, No chubs were
<br />found in swift wala, Y oun;! s'luawfish aJl(I
<br />ch II hs WC!'C C011111101l1)' taken in Ij uid water or
<br />shallow pools over silt, sand, :Inri occasionally
<br />oYer gravel hottoms.
<br />01 her fi"h spec iI'" I hat were cOlllmonly
<br />found ill Dinosaur National Monument dur-
<br />ing the present study were the speckled dace,
<br />Nhillichfhys o.\cullls; flanndmoulh suckcr.
<br />Calusl()JIIIl.~ lalipil/nis; bluehead sucker,
<br />Palllosleus ddlJh in liS : carp, CJprinus carpio;
<br />falhe:ld minnow, Pilllt'phalt's promdas; red.
<br />side shiner, Richardsonills ballealus; and
<br />channel catfisll; IdatUT/ls /llUlcfalus.
<br />
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