9435

• UCREFRP Catalog Number: 9435
• Author: Haines, B. and T. Modde.
• Title: Humpback Chub Monitoring in Yampa Canyon, 1998-2000.
• USFW Year: 2002.
• USFW - Doc Type: Project Number 22a4,
• Copyright Material: NO

List of Tables

Page
1. Characters used to separate humpback chub from roundtail chub . . . . . . . . . . . . . . . . . . 20
2. Dates, flows, types of gear used, and effort expended sampling for each trip through
Yampa River Canyon, 1998-2000. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
3. Adult humpback chub captured-recaptured, Yampa Canyon, 1998-2000 ...........22
4. Catch per unit effort for each type of gear used, Yampa River, 1998-2000 . . . . . . . . . . 23
5. Humpback chub multi-model population estimates for Yampa River, 2000 ......... 24
6. Simulation results demonstrating small sample bias and lack of precision . . . . . . . . . . . 25
7. Humpback chub (> 150 mm TL) catch statistics using electro fishing methods .......26

List of Figures

Page
1. Lower Yampa River study site. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
2. Longitudinal distribution of humpback chub captured by electrofishing and angling in the
current study (1998-2000) and in previous years (1985-1997), Yampa River . . . . . . . . 28
3. Length-frequency of humpback chub captured by electrofishing and angling in current
study (1998-2000) and in previous years (1985-1997), Yampa River. . . . . . . . . . . . . .28
4. Longitudinal distribution of juvenile Gila captured by seining, August 1998, Yampa

River. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

5. Length-frequency of humpback chub and roundtail chub captured by seining, August
1998, Yampa River ..................................................... 30
6. Percent of significant declines in slope that were detected at P < 0.05 for simulated
populations in annual decline of 0.00, 0.01, 0.05, and 0.10 ......................31

Key Words

Humpback chub, capture-recapture, catch per unit effort, monitoring, population estimate,
electro fishing, seining, Yampa River, Yampa Canyon, Gila cypha, Gila robusta

v