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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and line ;.;ere used for stor:;ach .3<1.c;;l11r.g. Stomach::; were collected ':':::"':::i

rainbow tro',lt and largemo1.lth bass and preserved in 10% forrr:t1lin ['Jr l:1ter

.analysis.

As ',.;ould be expec-:.ed in a population only t~,o years from intrcd'Jc:ion

into the lake, a marked size division was evide:1t in the 1963 and 1964

year classes. Condition factors we:::"e calculated using standard length.

RESULTS

Significant results are difficult to interpret with the cize of fish

samples obtained this year. So:ne fi:1dinGs will be il7iportant in buildi:-.g

future progra~s, ho~ever.

GRO~iTH MID CONDITION

Largemouth Bass

Bass planted in 1963 and captured this year ranged in total length

from apprOXimately 200mm to just over 420mm (Figure 3). The ranGe in

weight ",as 120 to 1750 grams. The large range in size and "'.eight undoubted.iy

reflects gr8uping the data for the entire year. If the data are brc;-;:en dc.,in

into collection periods short enough to elimin~te bias caused by fish grow-

ing through the long time span, it is difficult to arrive at meani:1[;iUl

conclusio:1s because of the paucity of fish collected during a,\y pe.::iod.

Data from ~cales sho;.:s that the bass had attained an average total le~gth

of about 275~~ by the end of their first year in the lake. Grow~h fro~ the

average size at time of planting was about 235m~} or about 20m~ (almost one

inch) per month. At the end of tteir first year, fish captured "e3.1' ILlll' s

Crossing differed ~y less than 5mm from those taken itl or below the Last

Chanc~ area (lower reservoir).

Bass planted in the spri:1g of 1S-6L. had attained a length of abo"ut

70mm by July and about lC5mm by December. This corresponds to a erc;-rth