WSP09012

• File Number: 8220.104.I
• Description: Flaming Gorge
• State: UT
• Basin: Yampa/White/Green
• Date: 2/19/1991
• Author: USDOI-BOR
• Title: Revised 1991 Final Work Plan for Flaming Gorge - Green River Studies ‎(Endangered Species)‎
• Water Supply Pro - Doc Type: Report/Study

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~ll Hypotheses to Test -
10. Increased adult fish movement during the winter
does not affect spawning success.
11. Winter fluctuations/flows do not affect overwinter
survival of young-of-the-year of native fishes in
the Jensen-ouray and lower Green River areas.
12. Recommended winter flows do not affect status of
non-native fishes.

SUMMARY 01' INTEGRATED STUDIES RECOMMENDED I'OR THE I'IVE-YEAR
IHVBSTIGATION (proposals for each study are attached):

SYSTEMATIC DATA COLLECTION AND RESEARCH (SDeR) The
cooperative-agency team recommended that during the five-year
inv~stigation, a systematic data-collection and research
effort must be initiated to directly assess effects of
seasonal operation of Flaming Gorge Dam on annual reproduction
and recruitment of fishes in the Green River system. SDCR
studies would include collection of long-term data on spring
movements and migrations to spawning locations, spawning,
larval drift, and age-O and age-l recruitment. The
Interagency Standardized Monitoring Program (ISMP) provides
for collection of adult and young-of-the-year fish, but
concurrent, long-term information needs to be collected
annually on migrations and spawning success to provide
correlation between native and non-native fish populations and
hydrologic events.

Assumptions Considered in Planning the SDCR Effort -
Framework of the SDCR effort needs to be sufficiently
simple to allow for continuity over time, flexibility as
information is gathered, and collection of sound,
quantifiable data covering important life-history stages.
Consideration was given to the ability to link new data
with existing data and information generated from ISMP
and other studies.
Critical issue is establishing links among reproduction,
recruitment of young fish, recruitment to adult stocks,
status of populations, and how hydrologic conditions
affect life-history parameters.
Because state of knowledge of the life history of
Colorado squawfish is relatively high, compared to
razorback sucker and humpback chub, SDCR studies should
initially focus on Colorado squawfish. Asknowledge of
the life history of razorback sucker and humpback chub
increases, the SDCR effort could be modified/expanded to
include these species.
There are two main Colorado squawfish spawning areas in
the Green River system (i. e., lower Yampa canyon and
Desolation-Gray Canyon), and representative sampling in
reaches downstream of each spawning area will provide an