WSP00173

• File Number: 8240.200.10.A
• Description: UCRBRIP Habitat Restoration
• Basin: Colorado Mainstem
• Date: 10/8/1997
• Author: UCRBRIP
• Title: Final Habitat Restoration Program FY 1998 Work Plan Part 2
• Water Supply Pro - Doc Type: Publication

3. Quantify amount of movement of age-O and age-1 fish
between autumn (15 Oct.)and spring (15 Apr.).

4. Calculate population and survi.val rates and compare
to CPUE to determine if CPUE reflects population
density.

5. Relate population and survival rates to fish size
and environmental factors (e.g., early or late runoff,
high winter flow, fluctuating winter flow) that may
affect survival.

The end product will be a report that contains information
that may be used to refine the Management Objective
population model for Colorado squawfish, suggest if CPUE is
a satisfactory indicator of population density and
overwinter survival, and relate overwinter survival to
winter conditions.

IV. Description of past performance on this or similar projects:

This project is an extension of Estimation of Winter
Survival. Movement and Disoersal of Youna Colorado squawfish
in the Green River (Haines et al. 1997), and it is based on
the techniques outlined in Evaluation of Marking Techniques
to Estimate pODu1ation Size and First-year Survival of
Colorado squawfish (Haines and Modde, 1996). These reports
established the procedures and provided four years data on
population size and overwinter survival. Survival estimates
in Haines et al. (1997) have been used to parameterize the
MO population model (Crowl and Bouwes 1997).

V. Study area:

The study area will be the upper (rmi 320 - 215 and lower
(rmi 120 - 0) Green River, Utah.

VI. Study methods/approach:

The approach of this study is to conduct capture/recapture
and CPUE sampling of young Colorado squawfish in 20 mile
river reaches in the autumn (15 October) and again in the
spring (15 April). The fish captured in five mile subreaches
will receive unique batch marks (syringe injected elastomer

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