8208

• UCREFRP Catalog Number: 8208
• Author: Osmundson, D. B., P. Nelson, K. Fenton and D. W. Ryden.
• Title: Relationships Between Flow and Rare fish Habitat in the '15-Mile Reach' of the Upper Colorado River.
• USFW Year: 1995.
• USFW - Doc Type: \
• Copyright Material: NO

TABLE OF CONTENTS
LIST OF TABLES ..........................................................iv
LIST OF FIGURES .........................................................vi
ACKNOWLEDGEMENTS ................................................... ix
EXECUTIVE SUMMARY .................................................... x
INTRODUCTION .............................................. ............1
Background ................................................. ............1
Approach Used for Summer and Winter Recommendations ............ ............ 2
Approach Used for Spring Recommendations ....................... ............ 3
Study Objectives ............................................. ............4
Adjacent Reaches and Companion Studies ......................... ............ 4
METHODS .................................................... ............6
Study Area .................................................. ............6
Summer and Winter Flow Needs ................................. ............ 7
Site Selection ............................................. ............7
Data Collection ........................................... ...........10
Aerial Video and Habitat Mapping ................... ........... 10
Water Depth and Stream-bed Monitoring .............. ........... 11
River Discharge ................................. ...........I1
Analysis ................................................. ...........12
Habitat Mapping Corrections ........................ ........... 12
Seasonal Partitioning of the Year ..................... ........... 13
Determining Preference For Habitat Type .............. ........... 13
Determining Flow Levels That Maximize Preferred Habitat ........... 14
Spring Flow Needs ............................................ ...........15
FISH HABITAT USE ............................................ ...........16
General .................................................... ...........16
Adult Colorado squawfish ...................................... ........... 16
Winter .................................................. ...........16
Spring .................................................. ...........16
Summer ................................................. ...........18
March and October ........................................ ...........18
Adult Razorback Sucker ....................................... ...........18
Winter .................................................. ...........18
Spring .................................................. ...........18
Summer ................................................. ...........20
Seasonal Partitioning of the Year ................................. ........... 20
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