9299

• UCREFRP Catalog Number: 9299
• Author: Anderson, R. and J. Mumma.
• Title: Aspinall Studies
• USFW Year: 1999.
• USFW - Doc Type: Annual assessment of Colorado Pikeminnow Larval Production in the Gunnison and Colorado Rivers, Colorado 1992-1996.
• Copyright Material: NO

TABLE OF CONTENTS

ACKNOWLEDGEMENTS............................................................................................................... ii

TABLE OF CONTENTS................................................................................................................. iii

LIST OF TABLES................ .......................................... .................................................................. v

LIST OF FIGURES........................................................................................................................ vii

LIST OF KEY WORDS................ ...... ....................... ................ .... ................................................ viii

EXECUTIVE SUMMARy............................................................................................................ viii

INTRODUCTION........................ .................................................................................................... 1

STUDY AREA.. ......... ................... .......... ..... ............... .................. ...................................................3

Flow Characteristics during the Study Period ........................................................................ 5

METHODS....................... ....... ................................................................. ........................................7

Field Collections.................................................................................................................... 7

Data Analysis......................................................................................................................... 7

RESULTS - COLORADO COLLECTIONS........ ......... .................................................................... 8

Larval fish - Total Catch........................................................................................................ 8

Species Composition and Relative Abundance... .................................................................... 9
Colorado Pikeminnow - Total Catch ......... ................ ...... ... ...................... ........ ...... ... ...........11
Colorado Pikeminnow - LOMA Catch Characteristics and Drift Estimates...........................12

- UTAH COLLECTIONS.. .......... .................................................................................. 15

Colorado Pikeminnow - Catch Characteristics and Drift Estimates .......................................15
Non Native Cyprinid - Catch Characteristics and Backwater Density.................................... 16
Non Native Cyprinid - Backwater Density, Colorado (ISMP)...... '............. .. .. .... ... .......... .. ... 17
Colorado Pikeminnow YOY Size and Survival......................... ..................................... ....... 18

DISCUSSION. ................... ........................................... ... .............................. ..................................19

Colorado Pikeminnow Distribution, Gunnison River............ ..................... ................ ........... 19
Colorado Pikeminnow Distribution, Colorado River ............................................................ 20
Colorado Pikeminnow Larval Catch Between Years and Stations, Colorado .......................21
Longitudinal Trends in Colorado Pikeminnow Abundance..............................:.................... 22
Colorado Pikeminnow YOY Size and Survival (Objective 2) ...............................................24
Colorado Pikeminnow Larval Drift and YOY Backwater Density (ISMP) ...........................25
Colorado Pikeminnow Larval Drift and YOY Backwater Density (Utah) .............................25
Non Native Cyprinid Backwater Density (Utah & ISMP) ....................................................26

SUMMARY AND CONCLUSIONS....................................... ....................................................... 27

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