Grand Canyon National Park 

Fisheries Program Updates, FY 2022

Emily Omana Smith, Brian Healy, Robert Schelly, 

Rebecca Koller
Acknowledgements

• So many hard-working seasonal staff, interns, and volunteers

• Funding and support: 

Photos from Amy Martin, Brian Healy, Emily Omana Smith, 

Melissa Trammell, Della Yurcik, Nicole Klein, Amy Washuta

Fish illustrations by Joe Tomelleri
Today (speed round)

Humpback Chub Translocation Monitoring

Bright Angel Creek Trout Removal Project

Planned 2023 Activities
Project title: Humpback Chub Translocation

Project elements: Not included in AMP workplan; relates to project G objectives

Project Objectives: To establish a second spawning population outside of the LCR or to 

use tributaries as “grow outs” to augment mainstem populations

Funding Amount & Source: primarily Bureau of Reclamation as well as NPS & Grand 

Canyon Conservancy

Cooperators: see previous slide

LTEMP goal addressed: Humpback Chub- meet humpback chub recovery goals, including maintaining a 

self-sustaining population, spawning habitat, and aggregations in the Colorado River and its tributaries 

below Glen Canyon Dam.
Translocations outside of the Little Colorado River
LOCATION DATES COMPLETED ACTIVITY

HAVASU CREEK October 8-11, 2021 Monitoring

HAVASU CREEK May 12-19, 2022 Monitoring

LITTLE COLORADO RIVER Cancelled- insufficient 

HBC for collection

Larval collection

BRIGHT ANGEL CREEK June 1-8, 2022 Monitoring

BRIGHT ANGEL CREEK, SHINUMO 

CREEK, HAVASU CREEK INFLOWS

June 15-26, 2022 Monitoring & 

Surveillance

BRIGHT ANGEL CREEK, SHINUMO 

CREEK, HAVASU CREEK INFLOWS

August 23- September 2, 

2022

Monitoring & 

Surveillance

FY 22 HBC 

Translocation 

Activities
Havasu Creek
Havasu Creek 2022 Abundance Estimate= 145

(95% CI 138-170)

Non-translocated HBC are 

now 90% of the population

Population growth rate for 

non-translocated HBC= 1.05 

(95% C.I. = 0.79 – 1.41)

No new translocations have occurred since 2016 and abundance estimates have

varied, but the population growth rate continues to indicate a stable population.

Mean relative weight= 89.5 

(95% C.I. = 87.3 – 91.4)-

slightly lower than the 

standard (100) but similar to 

past years Second reproducing population!
Bright Angel Creek
Bright Angel Creek 2022 Abundance Estimate= 12

(95% CI 7- 54*)

Why low survival?

- Trout predation & competition

- Hydrology

- Handling or electrofishing 

stress 

- Data availability 

Additional translocations will 

help to address hypotheses.

Plan to release a total of 1000 HBC over next several years, recommended in the HBC Genetics 

Management Plan (USFWS 2010), Comprehensive Fisheries Management Plan (NPS 2013), and 

Translocation and Refuge Framework (Van Haverbeke et al. 2016). 

2018 cohort: n= 116, 104 unique antenna detections*

PIT-tagging hatchery error

2020 cohort: n= 415, 39 recaptured, 15 unique antenna 

detections

Shinumo- translocated, LCR, and mainstem-tagged HBC 

also detected

Survival estimate= 3- 11% (95% 

CI) in 1st season after 

translocation;
Shinumo Creek

TranslocationsContribution to Mainstem

Shinumo Creek translocations 

contributed 43% of total abundance of 

the adjacent aggregation 

(superpopulation- 2010- 2022). 

Although Humpback Chub translocated to the creek were extirpated in 2014 and no new 

translocations have occurred there, translocated fish are still being detected and have 

augmented the nearby Colorado River aggregation. 

Annual average apparent survival was 

higher for translocated HBC than nontranslocated fish. 

Abundance (by occasion)

- 2012- 2015: higher for translocated 

than non-translocated 

- 2015: downward trend 

- 2017- present: translocated & nontranslocated fish have similar 

abundances
Havasu Creek 

TranslocationsContribution to Mainstem

Havasu Creek translocations 

have contributed 24% to the 

nearby aggregation

(superpopulation- 2011- 2022). 

Abundance (by occasion)

- varied significantly between 

groups at times

- Havasu-in situ abundance 

consistently lower than that of 

mainstem & translocated

Apparent survival was higher for 

translocated Havasu Creek HBC 

than non-translocated fish 

tagged in the mainstem.

Havasu Creek translocations have resulted in the establishment of a second spawning and 

recruiting population. Although the last translocation was in 2016, translocations continue to 

contribute to the mainstem Havasu Creek aggregation.
Humpback Chub Translocation Monitoring

Bright Angel Creek Trout Removal Project

Planned 2023 Activities

Today 

(speed round)
Project title: Bright Angel Creek Trout Removal

Project elements: Not included in AMP workplan; relates to project H objectives

Project Objectives: To benefit Humpback Chub and other native fishes in the Colorado River 

by reducing the risk of predation 

Funding Amount & Source: Bureau of Reclamation, with other funding from NPS and Grand 

Canyon Conservancy

Cooperators – see previous slide

LTEMP goals addressed:

- Humpback Chub- Meet humpback chub recovery goals, including maintaining a self-sustaining 

population, spawning habitat, and aggregations in the Colorado River and its tributaries below Glen 

Canyon Dam.

- Other Native Fish- Maintain self-sustaining native fish species populations and their habitats in their 

natural ranges on the Colorado River and its tributaries.

- Nonnative Invasive Species- Minimize or reduce the presence and expansion of aquatic nonnative 

invasive species.
Project 

Stipulations

All trout removed are 

prepared for human 

consumption (> 200mm) or 

provided to the Zuni or Navajo 

aviaries or wildlife 

conservation organizations1

for consumption by 

ceremonial eagles and other 

animals (< 200mm)

No electrofishing in Ribbon 

Falls Creek or tributary 

confluences

Sensitivity training for crews

1. due to covid-related restrictions
Bright Angel Creek Backpack Electrofishing

• October 21, 2021–

January 22, 2022

• 13 miles of BAC, plus 

tributaries

• 3-pass depletion 

sampling in BAC

• 1-pass sampling in 

tributaries & in high 

trout density areas
Bright Angel Creek 

Weir and fixed PIT antenna array
Grand Canyon 

is Stochastic!

October 5, 2021 August 17, 2021
Brown Trout

In 2021-22, abundance 

declined by 55% after 

2020-21 surge

Ripe or spent females 

increased from 2020-21

LF histogram was 

strongly bimodal

- Age-0 cohort

- Larger fish → evidence 

of a surviving remnant 

from 2020-21 
Rainbow Trout Abundance 

declined by 

55% after 2020-

21 surge

Captures* declined slightly 

from 2020-21 (from n= 

5632 to n= 4216)

More than half captured 

from the upstream Angel 

Springs reach where 

electrofishing is less 

effective 

Evidence of a strong Age-0 

cohort in BAC & ASP

In 2021-22, abundance 

declined by 74% after 

2020-21 surge

*Angel Springs not included in abundance 

estimate
Native Fishes Bluehead Sucker 

abundance declined by 

74% (n=625); no age-0 

captured, small cohort of 

age-1 fish 

Speckled Dace abundance 

declined by 88% 

(n=22,098); no discrete 

age-0 peak u

n0 mm TL 

Flannelmouth Sucker 

abundance declined by 

74% (n=5)

Humpback Chub captures 

declined 53% (n= 14); no 

age-0

Bluehead 

Sucker

Speckled 

Dace

Flannelmouth 

Sucker

All native fish abundance estimates remain above 2012-

13 baseline levels 
Translocation Big Picture

Havasu Creekbarrier (<~25,000 cfs)-

refuge for native fishes if 

warm-water invasives 

establish

Shinumo Creek- impassable barrier- good 

candidate for translocation. Rainbow Trout 

would need to be considered.

Translocations can have important 

contributions to the mainstem HBC 

aggregations and to Grand Canyon 

HBC conservation in general. 
Trout Removal Big Picture

Suppression of the large 2020-21 year-classes for both species has 

brought trout abundance estimates down to ranges seen after 

four or five seasons of effort following project initiation. 

Continued reproduction of trout in 

Bright Angel Creek, evident from an 

abundance of fish captured from an 

Age-0 cohort, indicates trout 

suppression will continue to be 

necessary 
Today 

(speed round)

Humpback Chub Translocation Monitoring

Bright Angel Creek Trout Removal Project

Planned 2023 Activities
FY 2023 Activities

Humpback Chub 

Translocations

- Havasu Creek- 1 monitoring trip (seeking $$ for the 

second)

- Bright Angel Creek- 1 

monitoring trip

- Mainstem monitoring- (seeking $$ for 2 trips)

- Deploy temporary PIT tag 

antennas

- Assist in HBC collections in 

LCR

Bright Angel Creek 

Trout Removal

- Install BAC antenna array

- Weir & electrofishing 

2022-23 in process

- Consultation for potential 

renovation
More FY 2023

Congratulations to Brian and Bob 

on their new adventures!

Hire new people!

NPS- funded pilot Razorback 

Sucker release

Conduct surveillance for 

warmwater invasives fishes- pursuing multiple funding sources
Questions? 

I am happy to talk anytimeEmily_Omana@nps.gov

928-638-7477