7625

• UCREFRP Catalog Number: 7625
• Author: Stone, R. C., L. Fields and K. Miller.
• Title: Lake Powell Post Impoundment Investigations.
• USFW Year: 1964.
• USFW - Doc Type: Progress Report No. 2,
• Copyright Material: NO

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for 75m and about 1. 7 for 115r.un fi~h. At abo\A.t 2.30:i'..r:1 the "L(" factor begiLs

a curvelinear increase. Condition factors for le~G:h Groups of 200, 250,

.300} and 350mm were 2.10} 2.3, 2.7, and 3.55} res?ectively.

Rainbm; Trout

Rainbow trout' taken in 1964 ranged from 160~~ to 460~m total

- ..'
.lengl.r...

. .
Inasmuch as the few individuals on either end of the distribution proba~ly

reflect recruitment from sources other than the major fingerling pl~ntings,

a length range of 210mm to 420mm would probably be most satiSfactory in

describing the population (Figure 3).

Data this year suggest a period of most rapid growth betwee:1 Febr~~~y

and July during the warming trend and before stratification develops.

rr'
....,ere

seems to be very little growth occurring from August into the winter conths.

Growth of the trout is depicted in Figure 4. It compares very favorably

'l.'i th rainbo..... trout grO'.-rth in other regions of the western states. It is

interesting that the Lake Povell growth curve for fish of less than 350::1~1

is a duplicate of the Flaming Gorge Reservoir length-weight curve for 196if.

Above that point the Flaming Gorge trout nearly cease gro'Nth while in Lake

Powell trout growth continues.

Condition of the trout declines slightly with increasing lengths over

about 300mm (Table 6). Trout below 300mm did appear to maintain abOClt the

sa::1e "K" factor during the year. Condition factors for 300, 350, and :'-OOtiu':1

are 1.75, 1.70} and 1.64} respectively. The decrease in ilK" for thE: larger

indi vidun.ls was most :J.pparcnt in the lat ter h<llf (AL1CUS L to J<ll1uary) 01' tLc

data year. From February to July, fish sampled at 340 and 380~i1m} for

example, had ilK" of 1. 78 and 1.64, while these sizes taken later had ilK"

of 1.65 and 1.50, respectively.

Cha:;.nel Catfish

The channel catfish has developed into the third sport fish of the