COLORADO RIVER SLOUGH

GREEN SUNFISH REMOVAL 

Mike Anderson; AZ Game and Fish

Mark Anderson; Glen Canyon NRA

Melissa Trammell; NPS

Brian Healy; Grand Canyon NP

Rosemary Sucec; Glen Canyon NRA
Cooperators

 Arizona Game and Fish Department

 National Park Service

 Glen Canyon NRA

 Grand Canyon NP

 North Cascades NP

 USGS-GCMRC

 Fish and Wildlife Service

 Bureau of Reclamation

 Western Area Power Administration

 Hopi, Hualapai, Kaibab Paiute, Navajo, and Zuni
 BOR: Funding, steady flows, HFE 

delay

Cooperative Effort

 NPS: Coordination, planning, 

compliance, communication, 

security, safety, logistics, labor

 WAPA: Steady flows

 FWS: Compliance, guidance, 

labor

 USGS-GCMRC: Mechanical 

removal, risk assessment, 

hydrology, fish collection, otolith 

extraction, logistics, labor, 

macroinvertebrate survey

 AGFD: Coordination, Initial 

detection, mechanical removals, 

planning, permitting, emergency 

approval (commission), lead 

implementation, logistics, labor
Overview

 Timeline

 Surveys

 Compliance

 Treatment
Treatment Timeline

July 6

Aug 4

Aug 27-28

Oct 7

Aug 12-14

Sept 11

Sept 30

Oct 5

Oct 23

Oct 26

Nov 1

Nov 7

Nov 12

Nov 13

 43 GSF captured in slough

 Mechanical removal recommended

 1st mechanical removal 954 GSF

 2nd mechanical removal 2,574 GSF

 Interagency meeting to discuss results 

of mechanical removal

 Risk Assessment completed by D. Ward

 Decision made to move forward with 

chemical removal

 Temporary block net placed

 NEPA compliance, tribal coordination 

completed

 AGF Commission approval

 Beneficial use removals conducted

Oct 28-29  Oct 26: Press Release

 Nov 2: Travel/setup

 Nov 3: Setup Treatment

 Nov 4: Treatment

 Nov 5: Neutralization

 Nov 6: Sentinel Fish/Demobilize

 Nov 12-13: Post treatment monitoring
Survey Results

 July 6 2015-AGFD-LF Rare Nonnative Fish Survey

 43 GSF Captured

 August 12-14

 First mechanical removal

 954 GSF captured 

 August 27-28

 Second mechanical removal 

 2,574 GSF captured
Compliance

 Risk Assessment (D. Ward)

 Treatment plan (AGFD, NPS)

 Notice of Intent/Pesticide Discharge Management Plan (AGFD)

 Tribal Coordination (NPS)

 Categorical Exclusion (NPS)

 ESA Consultation (NPS, USFWS, AGFD)

 Approval of environmental analysis (AGF Commission)

 Communication plan (NPS, AGFD)
Beneficial Use-Mechanical Removal

 Oct. 27-29

 Upper Slough 

 736 GSF salvaged (Zuni)

 Lower Slough

 39 GSF (Zuni)

 40 Carp (moved to main channel)

 70 Rainbow Trout (moved to main channel)

 1 Flannelmouth Sucker (moved to main channel)
Treatment

 Low steady flow (9,000 cfs) during treatment and 

neutralization

 Bioassay

 Application of CFT Legumine 

 Neutralization

 Post-Treatment Sentinel fish
Barrier – Turbidity Curtain

 3, 50’ sections, 6’ depth

 Can be made to order

 Floats and weights 

included

 Reusable

 Portable (150 

lbs/section)

 Impermeable (dye tests)

 $2500 including shipping

 2-4 handlers

Treatment 

 Based on bioassay results 

 Effective concentration 0.75 ppm 

 Treated lower slough at 1.5 ppm (2x minimum effective)

 9.3 L 5% CFT Legumine

 Treated upper slough at 3.0 ppm 

 Increased organic load consumes rotenone

 1.7 L 5% CFT Legumine

 Duration

 Planned 8 hour treatment 

 Increased duration to 24 hours
Treatment 

Date Species Lower Slough Upper Slough 

5-Nov-15 Green Sunfish 180 1,787

Common Carp 117 108

Rainbow Trout 146 0

Flannelmouth Sucker 3 0

Bluegill 1 0

Channel Catfish 1 0
Neutralization

 Applied potassium permanganate Nov. 5

 28 pounds in lower slough 

 4 pounds in upper slough
Post-Neutralization

 Sentinel fish to determine if site can be opened to public 

 Water quality

 Fish survive for 24 hours in treated water 

 Sentinel fish survive 24 hours (Nov. 6)

 Collect water and sediment samples
Water and Sediment Samples

 Collected prior to, during, and after treatment 

 Post-treatment samples must return to baseline levels 

 Per label and SOP 

 <90 ppb-public reentry

 <40 ppb-drinking water 

 <2 ppb-aquaculture

Sample Date Site Rotenone Conc.

11/3/2015 Pretreatment Up <2 (nd) ppb

11/3/2015 Pretreatment Down <2 (0.8) ppb

11/4/2015 During 1 49.9 ppb

11/4/2015 During 2 52.3 ppb

11/4/2015 During 3 99.0 ppb

11/6/2015 Upper Slough 2.3 ppb

11/6/2015 Lower Slough 1.9 ppb

11/13/2015 Upper Slough 6.1 ppb

11/13/2015 Lower Slough <2 (0.3) ppb

11/19/2015 Upper Slough 5.8 ppb
Post treatment monitoring

 Nov. 12

 GCMRC staff backpack electrofish upper slough and 

place larval light traps

 No fish captured during backpack electrofishing 

 Nov. 13

 GCMRC staff backpack electrofish and shoreline 

habitat in lower slough, check larval traps

 No larval fish captured

 No fish captured during backpack electrofishing

 Second treatment deemed not necessary
Beneficial Uses

 Purposeless killing within the Colorado River corridor is offensive to some 

tribes.

 Negatives can be offset by planning beneficial uses of the dead organisms.

 Prior to the treatment, as many non-GSF as possible were recovered and 

released or given to the Zuni aviary for feeding birds.

 During treatment, non-target organisms were saved to the extent possible.

 Rotenone-killed fish collected and frozen to benefit research efforts.

 Rotenone-killed fish cannot be used for food or feed by EPA label. Fish 

could not be used for fertilizer either

 Macroinvertebrates were sampled before and after the treatment to better 

understand the non-target organism impacts.
Prevention

 Strongly suspect they came through Glen Canyon Dam

 As Lake Powell elevation declines, incidence of escapement 

likely to increase 

 Smallmouth Bass of particular concern

 Annual treatment not desirable

 Strongly consider eliminating this habitat

E X P E R I E N C E Y O U R A M E R I C A
 Repeated chemical treatments

 Pesticides only treat symptoms

 Chemical use offensive to tribes and many others

 Pass through

 Cooling the slough with river water would remove the GSF

habitat

 EA/EIS, USACE, Recreation Impact (fishing, boat passage), Big 

Project

 Other Spots Exist (hidden slough, leopard frog marsh, springs)

 Turbines that Prevent Fish Passage

 Expensive, BOR Business, Lake Mead Fish

 Other ideas?!

Long Term
Acknowledgments

 NPS

 M. Trammell

 M. Anderson

 A. Rawhouser

 H. Anthony

 C. Nelson

 E. Omana-Smith

 K. Nez

 R. Sucec

 J. Jackson

 C. Janicki

 C. Admiral

 E. Janicki

 USGS-GCMRC

 C. Fritzinger

 D. Ward

 D. Harris

 T. Quigley

 D. Foster

 S. Felder

 R. Morton-Starner

 B. Vaage

 S. Felder

 BOR

 K. Grantz

 D. Speas 

 M. Crawford

 AGFD

 M. Dahlberg

 M. Underwood

 K. Bright

 S. Rogers

 C. Benedict

 L. Winters

 S. Anderson

 WAPA

 C. Ellsworth

 C. Dean

 USFWS

 S. Hedwall