Brown Trout Incentivized Harvest Program 

Glen Canyon National Recreation Area

1
Background

There are increasing threats to native fish populations in the 

Colorado River downstream of Lees Ferry. 

Brown Trout

Can successfully spawn below

dam and numbers have been

increasing since 2014

Green Sunfish

Successfully spawning in a small 

backwater area below Glen 

Canyon Dam. First discovered in 

2015 but possibly there since the

1990’s.

2
Brown Trout Population is Growing

BNT historically 

composed 2% of

catch

BNT Currently 

composed 12% 

of catch

3
Why Incentivized Harvest?

A tool within the EA that utilizes a 

tiered management approach to 

control non-native fish and other 

aquatic organisms to protect native 

fish in Grand Canyon and the 

recreational rainbow trout fishery 

from the dam to the Paria River. 

1. Incentivized Harvest (first tier)

- most socially acceptable

- least intrusive

2. Mechanical disruption of early

life stages (2nd tier)

3. Mechanical Removal (3rd tier)

ENVIRONMENTAL ASSESSMENT

EXPANDED NON-NATIVE AQUATIC SPECIES MANAGEMENT

PLAN IN GLEN CANYON NATIONAL RECREATION AREA AND

GRAND CANYON NATIONAL PARK BELOW GLEN CANYON DAM

National Park Service

Intermountain Region

Glen Canyon National Recreation Area

Grand Canyon National Park

September 2018

4
NPS Legal Mandates

Grand Canyon has a legal responsibility to protect native fish/wildlife

- Biggest concern is a threat to the downstream population 

of the endangered humpback chub. 

- Brown trout are 17X’s more likely to prey on other fish species

than rainbow trout.

- Brown trout can tolerate warmer downstream water temperatures.

- Brown trout can tolerate higher turbidities

Glen Canyon manages with AGFD

for a recreational rainbow trout 

fishery below Glen Canyon Dam.

- Unique opportunity to research

if anglers can assist in managing a 

high threat fish species.

Humpback Chub – Status Endangered

Illustration by Joe Tomelleri
Incentivized Harvest Components

• Reward for each harvested brown trout > 6 inches 

• - Begin with $25.00 with increased rewards during 

• summer months when fish may be harder to catch

• Sponsored fishing tournaments (delayed)

• Tribal youth sponsored fishing trips (delayed)

6
Program Duration and Goal

• Fully funded in 2021 with partial funding procured for

the following 3 years

• Not intended to eliminate the brown trout population

• Reduce the brown trout population to 2013 levels 

(2% of catch)

• Through the incentivized harvest program, if brown 

trout population can be reduced, it should eliminate 

the need for more intensive fish management tools.

7
Fish Collection Information

Picture of new data card

Visitor Center

Fish Cleaning Station

8
The Rules for the Incentivized Harvest

• Brown trout must be harvested legally between the dam and the Paria River Riffle.

• Anglers register by turning in brown trout heads and entrails along with the data card.

• Only heads from brown trout 6 inches or greater will be counted. NPS has determined 

head size for 6-inch fish.

• Plastic bags for heads, entrails, and data cards are provided at the Lees Ferry boat ramp,

fish cleaning station, and Navajo Bridge Visitor Center. Use only pencil for data cards. 

• Harvested fish heads, entrails and data cards can be deposited in the freezer at the collection

station located at the Navajo Bridge Visitor Information Center.

• Employees from NPS are not eligible to participate in the program

• All brown trout heads/entrails will be tallied at the end of each month. Checks will be 

mailed to the address presented on the data card. Checks will be distributed by Glen Canyon

Conservancy.

9
Other Funding?

10
Questions?

THANKS to AGFD, GCMRC, ASU, BOR, NPS, GCC, and AMP Angling Group 

resentatives who have helped to prepare all of the documents for the rollo 

he Incentivized Harvest Program. 11