8144

• UCREFRP Catalog Number: 8144
• Author: Valdez, R. A.
• Title: Evaluation of Habitat Utilization Curves for Endangered Colorado River Fishes.
• USFW Year: 1985.
• USFW - Doc Type: \
• Copyright Material: NO

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explainable? If there wer~ no significant differences, why weren't the data
pooled? If there arE: significc'lnt differences, does it invalidate the data
of the Co1oradoRiver collected by traditional means? If this is so, then
what fraction of the data bClse is unusable and comparable?

4. According to Tyus et ?of. (19b4), in dpscribin9 depths used by adult
Colorade sQua\'Jfi sh, "There was a si ani fi cant Idi fference (P = 0.01) between
Q<:P.ths rf'cordE':d from the Grepn RivE-rar,<1 i tSI'. tributaries (\':hitE: and. Yc:mpa
Rivprs)..." using radiotelemetry..di"ta. Does this invalicate pealing Green
al1G Yampil I\ivcr radiotelerr.etry depth da:.a as is cone in thp first H.U.
c~rvc? I
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5. It only "vJithin chJnnel" i1abitct Sel€ttien is consiCf.red (item 4 of
ueta E.xcluded, p2cr 1), isn't an important part nf 1;.r!e rivrrinE:: he.bitat
beinq ignorpri (i.G., flooded woeclanos, f!lOOdCa bottor!1s, ('Iff-channel
b~ckwaters)? I

b. how Cen adulT: Coloraclo sGu(I,'Jfish in Ithe Colorc3<iO,.Grec-n eM 'fampa
Riv~rs ~xhibit siml1ar aEpt~ ana velocity prdterences (p?ges 1 ana 3) when
tre geomorpholcgy of tnf three rivers is so d~tferent? Tile Colorad.o has at
If:ast threE' rEoions (Elack Rocks, \':('st\-J~terJ (,?taract Lanyon) with water
dE.pth ot 6t tu' WU feet ~'ir.en:: scuc.lfi sh hav!E' bte;n found. The GrE'el1 and
Y2rpa Rivf:rs do not exhibit. slIch r!cpths. IJre r.;~tc. collected from thesp.
cnor~cleus r!?oions c'xcll1CE:c fron thE: e.ni'llys;s? I

_. _ 7. It cannot bp cenc 1 oded th'- t We ter d~Ptr- qrceter t>12 n ~. 95 ft. is a
'1mlt.lng factor. ~J'trOlJt extraDolc'tlng, .I'I'Clter Clcpth of 1..~5 :0 }(1.0 feet
rney b~ a lin;ting t<:lctcr (itr,f"'1 ~, f!ssur:pt;C\~S, pcgc 1). b!~c?USF' the datn
only inaic?te this rr;ngp of vclups. Colorc-cd souiH;lfish hove bl"p.n fOllnd in
(]~I='HIS grE'?ter then lC'.C fEet. here these dr.tlc1 excl llvrd fror'1 tf1f- iinalysi s?
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E. ltfn 2 at ur:ta Utilizer' cr: pe~Q 4 is not clf,ar. \'ul~,iplyin?
rf-(crOfr rT:Pi"n co1u~r vt:10. citirs by t',;Jo, sir.cq JT!iCrCr'''bit2.,t vC'.loc;tics lJSt:C
by tilt: fish ..E:fA only ;>bcut l/~ thr r:<ean ct.lur;1f1 vC'loci-::y rt'(.rc:ser,tac by
c;sso(.iatl..:d CE:lls in tr')( Ly(1ri'ulic nO(:E-l, ir:C::ilcute:s ti:c USe of ttie inrlirect
pilrametE:r analysis. ~'Jas ttlr frecucncy (lnalysis uscd to ~eneri"t12 rhis curve
for nonspawninq velocity of acult SCUClwfish,1 or was a rOr'lbincti('lr, ot dcta
analysis techniques uspd? (see s€cticn 2.4 of Ithis aocUMent)
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9. Th~ logic for not developing sUbstr8~e utilization cvrvps fer ~oult
nonspawning Colorado sQuawfish appears to be 1easonablf>,

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2.2.2 Anult CclorrH~o s<1ua"Jfish steging poth, velocity and substrClte

1. ThE' depth p~ra~Pter for this cC\t~~ory and the 0f:nt"ratE'c1 li.U. curve
(p.,ses t - 7) appt:or to be' logically nerivE:'d.] hO\'Jcvpr, l'S in trH' trcatmf.'nt
on nonsp~.minc (irpt.rl, till do:;; arT lir.ited 10 10 f~~ft. ~,rc ttlfre c\'cper
~re~s used by st~cino scua~tish? !

') . u . - , '1 f I 1 1" ( 8. )
'- nO"J r;c tilL' moce e:r: rangC' 0 - 1n1'Cln "'J(lter co ur.m \'(' OCltH'S pagE' '
r.or1rc:<rl..' ',-Jith cctudl tirlc 1Tc(!sun'mL'/lts? webs this rncen thilt fir' indirect
p?rCltTletcr ani\lysis .....;>5 p(:Y'torl1~ec? flo"'J mu~r. tield vnlidction h"'s this
hytiraulic ~odel r~ceivFd? !
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