9489

• UCREFRP Catalog Number: 9489
• Author: Mueller, G.
• Title: The Role of Stocking in the Reestablishment and Augmentation of Native Fish in the Lower Colorado river Mainstream ‎(1998-2002)‎.
• USFW Year: 1998-2
• USFW - Doc Type: 03-288,
• Copyright Material: NO

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Table of Contents

Page

Executive Summary.................................................................................................................................... iv

Introduction........................................................................................ ......................................................... 1

1. Fish Surveys: Davis Dam to Lake Havasu ...........................................................................................2

Introduction.......................................................................................................................................... 2

Methods......................... ...........,..... ................ .................... .......................... .......................... ..... .........3.

Results and Discussion.................. ................................................................ .......................... .............3

Passive Netting......................... ....................................... ...... ....... ......................................... ......... 3

Visual Surveys... ...................... ........... .......... ....... ...................................................... ....................5

Light Trapping......................... ....................................... ...... ........... ............................... ...... .........6

Distribution and Relative Abundance................................................ ..... ........................... ............9
Physical Description of the Upper and Lower 40-krn River Reaches ............................................9
Differences in Fish Distribution and Relative Abundance............................................................. 9

Native Fish............................... .... ........ ........ ........ .................................................... .......... ............ 10

Bonytail ............... ............... ....... ................................... ......................... ....................... ................. 10

Flannelmouth Sucker................................. ............. .......... ........ .......... .................... ......... .............. 10

Status and Existing Risks................. ...... ..................................... .................................. .............. ... 19

2. Telemetry Studies...... ....... .............. ..... ....... ..... ........... ....... ......... ....... .... ... ..... .......... ........... ........ ....... ... 20

Resident Fish Tests................. ...................................... .......... ......... .............................. ................ 20

The Importance of Physiology and Behavior in Survival ..............................................................20
Site Acclimation and Physical Conditioning Tests ...................................... ..................................21

3. Stocking Risk Assessment.................................................................................................................... 22

4. Bibliography for the Big River Fishes. ....... .......... ........ .......... ............. ..... ................... ........ .......... ....... 24

5. The Role of Stocking in Management and Recovery ...........................................................................25
Bonytail, Flannelmouth, and Razorback Suckers: Contrasting Survival Stories............................25

Stocking Comparisons. ..... ........ .... ......... .............. .............. ... ..... ............. ..... ............ .......... ........ ....25

Habitat Preference. ................. .... ................. ........ ......... ........ ........ .......... ........... .......... ..... ......... ....26

Results of the Recent Endangered Fish Stocking Programs .................................................................28

Recommendations....... ............. .......... .......................... ... ...... ..... .... ......... ... ..... .... ............... ........ .... 29

Acknowledgments....................................... ............................................................................................... 30

References Cited................................................................................ .......... ...............................................31

Appendix. Summary tables offish numbers, average lengths, weights, and ranges ...................................35

Tables

Page

1.1 Sample composition (%) of fish collected in the Colorado River between Davis Dam and
Lake Havasu from October 1999 to May 2002 ................................................................................. 5

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