E X P E R I E N C E Y O U R A M E R I C A

Non-native Fish Control 

in Tributaries:

Grand Canyon National Park

Brian Healy, Clay Nelson, Emily Omana Smith, Melissa Trammell, David 

Ward, Mike Yard, Dave Speas, Marianne Crawford

National Park Service

U.S. Department of the Interior

Grand Canyon National Park

Joe Tomelleri Illustrations
E X P E R I E N C E Y O U R A M E R I C A

Cooperators

•Funded by Reclamation and NPS

•Volunteers (several thousand hours)
Trout Control Projects 

Shinumo Creek –

Rainbow Trout

Bright Angel Creek –

Rainbow and Brown Trout

E X P E R I E N C E Y O U R A M E R I C A
E X P E R I E N C E Y O U R A M E R I C A

Project Background/Methods

 History: Trout initially introduced to GCNP,1920’s and 

1930’s 

 Non-native Trout Control: Conservation Measure for 

Humpback Chub in Biological Opinion (USFWS 2008, 

2011) 

 NPS Comprehensive Fisheries Management Plan 

(CFMP) 2013

 Non-native trout control via electro-fishing:

 Shinumo Creek, Bright Angel Creek

 Angling and netting
Goals and Monitoring

 Goals:

 Improve Survival of Juvenile Humpback Chub

 Restore Native Fish Communities

 Questions/Uncertainties:

 Effectiveness (mechanical)?

 Impact to native fish?

 Monitoring:

 Native fish trends:

 Abundance & Survival

 Non-native fish trends:

 Abundance and size structure
Shinumo - Results

 70-94% of Trout removed (2010-2013 electro-fishing)

 Trout capture probability (efficiency) related to fish 

size: Range 0.38 to 0.88
Shinumo - Results

 70-94% of Trout removed (2010-2013 electro-fishing)

 Trout capture probability (efficiency) related to fish 

size: Range 0.38 to 0.88
Rainbow Trout Size Structure

 Spurgeon et al. in 

review: RBT > 200 mm 

more likely to be 

piscivorous

 
E X P E R I E N C E Y O U R A M E R I C A

 February 2013

Rainbow Trout Size Structure
E X P E R I E N C E Y O U R A M E R I C A

Bright Angel Creek Trout Reduction 

Project

Actions: Remove Brown and Rainbow Trout

1. Install and operate a weir (fish trap)

2. Backpack electro-fishing for monitoring and removal

3. Boat electro-fishing: Mainstem/Bright Angel Inflow

Preliminary Data/Analysis In Progress
E X P E R I E N C E Y O U R A M E R I C A

Bright Angel – Electro-fishing Effort

 Stream Length

 Bright Angel Creek = 21km/13 miles

16.3 km
E X P E R I E N C E Y O U R A M E R I C A

Bright Angel Creek - Results

 Lower 600m: October 2010 – Spring 2013

 Proportion removed (3-passes): 70 – 91% 
E X P E R I E N C E Y O U R A M E R I C A

Results – Electro-fishing

 2012-13: Species composition

Phantom 

Creek
Phantom 

Creek 

Confluence
E X P E R I E N C E Y O U R A M E R I C A

 2012-13:

 16 total tagged recaptures (3 rainbow, 13 brown trout)

 Initially tagged in the mainstem

Trout Recaptures –
E X P E R I E N C E Y O U R A M E R I C A

Results – Stream Electro-fishing

 Bluehead sucker survival: Preliminary/In progress

 Number of BHS captured/tagged:

 October 2010: 4

 January 2011: 46

 October 2011: 77

 January 2012: 63

 Fall 2012-13 : 338
E X P E R I E N C E Y O U R A M E R I C A

Bright Angel Inflow– Electrofishing

 80% trout reduction goal

 Estimate of 20 nights of electro-fishing needed

 November-early December (trout aggregated)

 High Flow Experiment – cut removal trip in half

 Flooding in tributaries = muddy water

 Result = 2 nights/1 pass of clear water electrofishing

 10 total nights

 Removed:

 1370 RBT

 336 BNT
E X P E R I E N C E Y O U R A M E R I C A

Weir –
E X P E R I E N C E Y O U R A M E R I C A

Weir Results –

 2012-13 Installed early October – operate through 

early/mid-March

 Expanded slightly to more fully encompass spawning 

periods

 Weir Captures:

 2010-11: 105 Brown trout, 107 Rainbow trout

 2011-12: 32 Brown trout, 55 Rainbow Trout

 2012-13: 176 Brown trout, 36 Rainbow trout 

 2013-14: In progress (installed September 30, 2013)
E X P E R I E N C E Y O U R A M E R I C A

 2012-13: Removed (approx.)12,470 brown trout, 

1,735 rainbow trout 

 Beneficial us policy employed (per NHPA Section 106)

 Efficiently remove trout using electro-fishing

 Expect compensatory response - future control needed

 Preliminary results:

 Electro-fishing doesn’t appear to be impacting natives 

negatively

 Bright Angel Creek Brown trout control may result in 

increased native fish abundance

 Future: 

 Project, with monitoring, continues, CFMP decision 

point after 5 years

Summary –
E X P E R I E N C E Y O U R A M E R I C A

Phantom Ranch Boat Beach, circa 1911 

Questions?