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<br />
<br />~..~-- ~'1~~~
<br />
<br />,=.:.::..~~M'Otfett:(1942) c'Onsidered that 'Only ab'Out 250r 30 miles QfThe river
<br />below Boulder Dam were imp'Ortant as trout waters. Trout have been
<br />caught much furtherd'Ov....nstream, and undoubtedly will c'Ontinuet'O be
<br />caught there occasi'Onally. H'Owever, these are stray migrants mostly
<br />du:ringthe cold season. N'O permanent establishment 'Of traut could be
<br />expected in the l'Ower river.
<br />
<br />Water Chemistry
<br />
<br />Many agencies have made analyses of C'Olorad'O River waters, amI a
<br />_.:..-:::::-_,detailOO.studY 'Of these analyses might have c'Onsiderable value in deter.
<br />- . IJli.Ding the effect'o{:cliemlcaTconditions;upon--:its-atluatic fa.una---,While
<br />na such study is attempted here, the statement can be made that in
<br />general the chemistry 'Of the river water aff'Ords c'Onditi'Ons far abundant
<br />food supply and good growth 'Of fish. '
<br />The supply 'Of dissolved 'Oxygen f'Ound in l!luxface samples fram the
<br />river and its connected lakes in 1942 (range, 7.6-11.4 p.p.m.) is more than
<br />su.ffi.cient f'Or the adequate maintenance 'Of fish life. . AlthQugh there is
<br />comparatively little plant life, there is ample chance far oxygenation
<br />thraugh agitation. It was impossible ta obtain oxygen samples fr'Om the
<br />deepest part of Lake Havasu when the reservair was full. The dissolyed
<br />'Oxygen content taken in this reserv'Oir 'Opposite Needles B'Oat Landing
<br />'On February 15, 1942, varied from 10.0 p.p.m. (surface) to 9.6 p,p,ID.
<br />at the bottam (27 feet). Samples takeniust ab'Ove Parker-Dam on May
<br />20,1942, sh'Owed 8.2 p.p.m. at the surface and at a depth 'Of 10 feet j 7.6
<br />p.p.m at a depth 'Of 20 feet; 6.8 p.p,m. at the b'Ott'Om (40 feet). It would
<br />be 'Of interest ta make further analyses especially in summer when the
<br />lake ishigh. H'Owever, the character 'Of Lake Hava.su is such that a
<br />rather complete mixing of the water is indicated, and the usual absence
<br />'Of decomp'Osing 'Organic matter wauld appear t'O preclude much depletion
<br />'Of 'Ongen.
<br />There has, h'Owever,been an 'Occasi'On in recent years when an nnllSU-
<br />ally high 'Oxygen demand has been created at the l'Ower end of this reser-
<br />voir and in the river below acc'Ompanied by a severe l'OSS of fish. On Sep-
<br />
<br />.:
<br />
<br />--_.._--~--
<br />.
<br />
<br />134 ,d"
<br />
<br />CALIFORNIA FISH AND GAME
<br />
<br />
<br />FIG. 63. Downstream view of Parker Dam showing the mass
<br />of drift w3shw In by a flood on the Wlllla.ms River,
<br />Photograph by State Division of Fish a.nd Ga.me, Sept.
<br />1939. .
<br />
<br />
<br />THE FlSHEBY OF THE LOWER COLORADO'RIVER . JIDi..,
<br />
<br />'~~to7, 1939, a flashfiood~eurredin th~-.Bill Williams ii.-;;
<br />~}Ja~~e amount of organic debriS into: Lake lIav8.su~ Dead~' ,
<br />.~tfisli, slllifish. and largem'Outh bass) were f'Oundfor10mifes
<br />_,-Col'01"ad~ RIver ~el'Ow Parker Dam. .Analysis 'Of the water
<br />.,pon exceptIonally hIgh 'Oxygen demand due to its high 0 ' .
<br />~",:::'\'From rep'Orts of Mr. C. L; T'Owers of the California Di~~t
<br />~~. ~ame's P'Oll~tion Detail! dated Oct. l6 and 20, 1939.} . . 0 -,
<br />..~nver w~ter IS characterIStically alkaline. Readings 'Of pH 76
<br />",esh'O":l ill Table 1 ; and readings from pH 8.1 to 8.4 were tak~n
<br />,~us pomts a~'O~~ the lower river during the 1942 field work
<br />:orange alk~linit1es from 152 to 176 p.p.m. CaCOs were recorded
<br />,.' ,.,,;~~~r~~~~.a.t~!"~_':'!_~ivf4hUUh.e.ley~Js ran ,3
<br />clihigher ill early ~942 m ~er~all~, Imp'Ortanf:fiSliiiiifwateri,-such-''::,.:7 ,:=
<br />.~erd~ Sl'Ough, which carrIes IrrIgatI'On drainage int'O the river .
<br />.,~~ Lake, which is entirely cut 'Off from the river-304 p p m'
<br />_,~.:and31~.for the latter.' . . .
<br />
<br />, ' r' '." TABLE 1
<br />'~~ry_s of: water aamples of the Colorado River at the Yuma Ga in
<br />,.Jto~~~fore and after control by Boulder Dam, February 1935 II II
<br />~trol'by Boulder Dam .
<br />
<br />19U
<br />January 2
<br />
<br />193f
<br />ApriU
<br />
<br />1934
<br />July 2
<br />
<br />1935
<br />JaIloary 7
<br />
<br />8,<<7
<br />1
<br />2.9iO
<br />109
<br />1,145
<br />8,2
<br />0,21
<br />109 '
<br />43
<br />218
<br />12
<br />201
<br />455
<br />192
<br />7
<br />11
<br />
<br />8,883 9,426 .
<br />1 1
<br />1.400 2,450
<br />114 213
<br />826 1,665
<br />7,7 7,9
<br />0,12 0.24
<br />79 147
<br />28' . Gl
<br />121 :M2
<br />o 0
<br />160 237
<br />283 587
<br />121 240
<br />7 9
<br />\......_....... ___.u___...._
<br />
<br />8,171'
<br />1
<br />2,660
<br />188
<br />1,340
<br />7,6
<br />0.16
<br />137
<br />SO
<br />211
<br />o
<br />271 '
<br />535
<br />184
<br />9
<br />7
<br />
<br />[ 1943 Ii 1943 I 1948 \ 1943
<br />! January 1-10 April 1-10 , I July 1-10 \ October 1-10 J
<br />
<br />17.007 639 lIen \
<br />10 9 ' .so I~ U
<br />11.214 _ 9
<br />100 ~05 .-. ...----ios--.-'..u.--ioiu..
<br />705 .06 699 691
<br />7.8 8.2 7,9 77
<br />0,18 0,07 0,11 0'09
<br />93 98 93 94'
<br />~ 26 27 27
<br />_______ 101 99 92
<br />ll:P ~--::::::::::::::::::::::: ..---- '289~~--- - :: :::::i~:::: :::::::i~~:::: . ------is:----
<br />312 319 306
<br />627 75 73 72
<br />2 1 2
<br />12 14 14
<br />Table lot &Ild,~~!:,ry ,~o, 17007 in Table I.B, made by tbe United Stat.. Bureau of Plant Ind.....
<br />_ .' VVBI" ......onua, from """,pi.. collecUd by the t'nited State! Bureau of Reclamat.ion at
<br />i-B, ~b N~, 63y9, 1159. ~3S3, made by the UniUd Stat.eo Geological Survey Albuqu...que,
<br />~..... 'lIt lD wna MlWl Canal. '
<br />
<br />
<br />-.:.-,'-=-~~~-
<br />
<br />-~';:"''',-~~
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