8096

• UCREFRP Catalog Number: 8096
• Author: American Fisheries Society.
• Title: Proceedings of the 19th Annual Meeting, Colorado - Wyoming Chapter, American Fisheries Society.
• USFW Year: 1984.
• USFW - Doc Type: March 7-8, 1984.
• Copyright Material: NO

EVALUATION OF REPRODUCTIVE HABITAT IN THE
EMERALD LAKES SYSTEM, COLORADO
LEO D. LENTSCH
ABSTRACT
In 19$0, rainbow-cutthroat hybrid trout (Salmo gairdneri x
Salmo clarki) reproductive habitat of the Emerald Lakes system was
evaluated by habitat quantification and spawning stock identifica-
tion. quantification of reproductive habitat indicated almost 2.5
times more larvae were produced in the outlet than inlet. This in-
equality was not due to a difference in the amount of surface area
available (inlet 2.5 times greater than outlet) or to the number of
eggs deposited by females (inlet 740,000; outlet 690,000); however,.
it was related to a difference in the amount of area actually used
for spawning (spawning habitat) (outlet 1.4 times greater than inlet)
and to the amount of area that produced larvae (reproductive habitat)
(outlet 4.7 times greater than inlet). Number of circuli to the
first annulus on scales was used to identify the natal area of an
individual trout (spawning stock identification). Fish with 10 or
fewer and 11 or more circuli were considered outlet and inlet origin,
respectively. Counts of the number of individual fish belonging to
each spawning stock (inlet or outlet) indicated almost 3 times more
fish originated in the outlet than inlet. Comparison of habitat
quantification and spawning stock identification procedures. with
precipitation and temperature data indicated reproductive habitat in
the inlet was regulated by the synergistic effect of water flow and
temperature.
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