NonBasicSpecificComments05

• Title: Comments 5
• Date: 10/23/2003
• SWSI - Doc Type: Comments

10~23/20Q3 10:40 FAX

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Figure 41 A portien of the t.rpp~r Sa.Jt
River depic:ting stud,. n::3C'h~ and Cliti.
.n"u!JtI:S of tt~nlt cove,. i5.nd bJ"Own trO\1.t
hioma.ss in eaGl, te:3ch.

among stre3ms (Table 2). ;For exampJe~ the ;analysis
indic:aled thac returning nat.ural flows to the Upper SaIl
Rive.. could lead to a large bionlCl$-5 (S82 kg) and ~bun'"
d3nc:e (7487 .A.sh ~ 1 yr::a.r- old) of brown tt"01Jt,. whereas
natura] flows in Dry Cree,k W"Ollld generate a relatively
]Q\Y blo2'oa!)S (41 kg) a.nd a.bundance (805 fish) of
bl'own U'Q\.H. The diffel~e(lct: berwc~.n the twO St~'Tr1S
","as; prlmar11y the result of differences in strea!n length,
l)ut al~o the :avaj]abUiLy of cov!:r over the lengd'1 of the
strealll segments.
We asse~c::d [h e effecrs of \Ian aU8 proportions 0 f
l1arurat aver.a.ge summer flo"'NS (20%-60% of AtlF) on
bro\vn trOt,lt biomass and ab".ndartcq (Ta.ble: 3). Vlhen

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Trout Responses to Flow Restoration 141

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Biomass kglha
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CoveJ~ %
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---3045
-- 4.5-60

flom were rr::nl1f:ed f(l 1e.'i..lI!i Ih~n natural l~v.el~. bir..nn3.!S
and densi ty of broWl'). trout wer-e predicted fO dccU:n e in
all streams. For example. with a r.;duction from na~ural
flows (78% of AOF) t<J 40% nf t\DF, the hj~mass W~S
predicled to decline by S5% in tbt: srudy screams. Sim-
ilarly, jf flows 'Were ."educed to 20% of ADFJ bionJ3.93
de~lin~rt hy ~5%~
Bccau$C managers often negotia1:e for a specific
amOlu1t ot" ''later, we computed the effects of specific
!lJmm~r flows (0.21), 0.50, anrlll.. 75 nl~ /~ec) on brown
trQU l biolnass and abundance in the.s rudy streams (Ta-
ble 4). Woen We evaluatcd the effectS of a 0.25 m9/sec
disr.harge on each ~trea.m.. we found that the resulting