7090

• UCREFRP Catalog Number: 7090
• Author: Archer, D. L., L. R. Kaeding and H. M. Tyus.
• Title: Colorado River Fishes Monitoring Project Final Report.
• USFW Year: 1986.
• USFW - Doc Type: Lakewood, Colorado.
• Copyright Material: NO

Using controlled releases of high (4000 cfs) and low flow (800 cfs) from
Flaming Gorge Dam, seining was attempted for YOY Colorado squawfish to
evaluate fish behavior during changes in flow.

Sensitive Reach Designation

A meeting was convened on 31 May 1984 in the Denver FWS Regional Office
to discuss upper Colorado River modeling for endangered Colorado River
fishes. Representatives from various sections of FWS were present
(WELUT, CUP, ES, SE, HR). At that time a variety of parameters were
identified as probably influencing the well-being and survival of the
endangered fishes. Subsequent to that meeting, a second meeting of FWS
biologists was convened in Grand Junction on 13 June 1984 to refine the
list of important parameters and life-stages for which data were available
and to develop criteria for the delineation of ~portant reaches. These
criteria have subsequently been further refined through discussions
between various biologists, hydrologists and modelers and have been
adopted by the Biological Technical Subcommittee of. the UCRCC. Much of
this effort by CUP personnel was in lieu of the field investigations
and data analyses which were prescribed for 1984 in the CRFMP Memorandum
of Understanding.

Life-stages

The life-cycle of each of the three fishes treated was partitioned into
phases according to size, function or habitat requirements. Because of
a lack of data the bony taU was not included.

Life-stages were partitioned accordingly:

Colorado squawfish

Adult (450+mm TL)
Spawning
Larvae (8-24 mm TL)
YOY Post-larvae (25-59 mm)
Juvenile (60-449 mm TL)

7