U.S. Department of the Interior

U.S. Geological Survey

Colorado River fish monitoring in Grand 

Canyon, Arizona: 1990-2013 humpback 

chub, Gila cypha, aggregations.

William R. Persons1 (wpersons@usgs.gov)

David R. VanHaverbeke2

Brian Healy3

1 Grand Canyon Monitoring and Research Center

2 U.S. Fish and Wildlife Service

3 Grand Canyon National Park

Glen Canyon Dam Adaptive Management Program

Annual Reporting Meeting

January 28, 2014
Aggregation: 

“a consistent and disjunct 

group of fish with no 

significant exchange of 

individuals with other 

aggregations, as indicated 

by recapture of PIT-tagged 

juveniles and adults and 

movement of radio-tagged 

adults”

(Valdez and Ryel, 1995).
Map courtesy of Tom Gushue, GCMRC

52

3,482

57

98

13

5

Valdez and Ryel 1995

Population estimates 30M

LCR

BAC

SHI

MGG

HAV

PUM

STE
Outline:

 Problems with population estimates using pooled 

capture probabilities

 Ultrasound

 Trends in catch rates

 30 Mile, Shinumo, Havasu

 Catch per unit effort

 Distribution

 Contribution of translocations

 Future directions
Ultrasound Results

(see Poster session for more detail)

 Identified egg 

development with 

ultrasonic imaging

 Documented egg 

development in

 LCR

 Colorado River

 Havasu Creek
Fish / 24 hr. Fish / 2 hr.

Catch per unit effort of HBC > 150 mm

PRELIMINARY DATA from GCMRC fish capture history database, SUBJECT TO REVISION, DO NOT CITE
Map courtesy of Tom Gushue, GCMRC

TRAMMEL NET CPUE

PRELIMINARY DATA from GCMRC fish capture history database, SUBJECT TO REVISION, DO NOT CITE
30 Mile range expansion?

PRELIMINARY DATA from GCMRC fish capture history database, SUBJECT TO REVISION, DO NOT CITE
Shinumo translocations contribute 

to mainstem aggregation:

PRELIMINARY DATA from GCMRC fish capture history database, SUBJECT TO REVISION, DO NOT CITE
Where do Shinumo Translocations Go?

96/186 0/63 3/276

SHI STE MGG

+

LCR 2 fish

PRELIMINARY DATA from GCMRC fish capture history database, SUBJECT TO REVISION, DO NOT CITE
Havasu translocations contribute to 

mainstem aggregation:

PRELIMINARY DATA from GCMRC fish capture history database, SUBJECT TO REVISION, DO NOT CITE
Site Fidelity 1989-2013 

RECAPTURE LOCATION

MARK n 30M LCR BAC SHI STE MGG HAV PUM Total Site 

Fidelity

30 M 72 31 3 34 91.2%

LCR 51,061 2 22,093 1 1 1 22,098 100.0%

BAC 30 1 1 0.0%

SHI 1,017 1 101 102 99.0%

STE 88 1 3 2 6 50.0%

MGG 355 73 73 100.0%

HAV 680 2 62 64 96.9%

PUM 36 3 3 100.0%

Total 53,339 33 22,101 0 101 4 76 63 3 22,381

Includes LCR antenna detections

PRELIMINARY DATA from GCMRC fish capture history database, SUBJECT TO REVISION, DO NOT CITE
Key findings:

Increasing abundance and distribution of HBC:

 Key Drivers: 

 Generally warmer than normal water during last decade, 

especially 2004, 2005, 2011

 Translocations 

 Shinumo Creek: 1,102 fish 2009-2013

 Havasu Creek: 840 fish 2011-2013

 Mechanical trout removal at LCR confluence 2003-2006, 2009 

and system wide decline in trout (2000-2007)

 Good production of humpback chub from Little Colorado 

River and high juvenile survival
Future Directions:

 Increase sampling effort at areas outside of 

known aggregations.

 Reduce trammel net effort at most locations

 Investigate use of slow shocking for small 

humpback chub

 Humpback chub natal origins project 2014

 Continue Portable ultrasound research

 Revise otolith microchemistry project
Contact Information:

William Persons wpersons@usgs.gov

USGS Grand Canyon Monitoring and Research Center

928-556-7323

David R. VanHaverbeke randy_vanhaverbeke@fws.gov

US Fish and Wildlife Service

928-556-2154

Brian Healy brian_healy@nps.gov

Grand Canyon National Park

928-638-7453