Mechanical Removal of Non-native Fishes in the Colorado River

within Grand Canyon

Lew Coggins, Michael Yard, Lew Coggins, Michael Yard, Daniel Gwinn, and Clay NelsonDaniel Gwinn, and Clay Nelson11

USGS, Grand Canyon Monitoring and Research CenterUSGS, Grand Canyon Monitoring and Research Center11Arizona Game and Fish DepartmentArizona Game and Fish Department

The Historic Fish Community in Grand CanyonThe Historic Fish Community in Grand Canyon

Humpback Chub (Gila cypha) Bonytail Chub (Gila elegans) Roundtail Chub (Gila robusta)

Colorado Pikeminnow (Ptychocheilus lucius ) Speckled Dace (Rhinichthys osculus )

Flannelmouth Sucker (Catastomus latipinnis) Bluehead Sucker (Catastomus discobulus)Razorback Sucker (Xyrauchen texanus)

Modifications to the Aquatic EcosystemModifications to the Aquatic Ecosystem

The Present Native Fish CommunityThe Present Native Fish Community

Humpback Chub (Gila cypha)Federally Endangered

Bonytail Chub (Gila elegans)Extirpated

Roundtail Chub (Gila robusta)Extirpated

Colorado Pikeminnow (Ptychocheilus lucius ) Extirpated

Speckled Dace (Rhinichthys osculus )Locally Common

Flannelmouth Sucker (Catastomus latipinnis)AZ Species of Special Concern

Bluehead Sucker (Catastomus discobulus)Locally Common

Razorback Sucker (Xyrauchen texanus)Extirpated

The Recent Fish Community in Grand CanyonThe Recent Fish Community in Grand Canyon2000-2001 Observed Species Composition in the Colorado River Using

Electrofishing and Netting Methods

Salmonids80%

Bluehead Sucker

1%

Flannelmouth Sucker

7%

Humpback Chub5%

Speckled Dace1%

Cyprinids6%Centrarchids

0.1%Ictalurids

0.3%

Background and MotivationBackground and MotivationAdult Humpback Chub Abundance (Age 4+)

Year

A

dult

Abu

ndan

ce (A

ge 4

+)

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

0

2000

4000

6000

8000

10000

12000

In 2002, concern for the In 2002, concern for the downward trend in downward trend in humpback chub humpback chub Gila cyphaGila cypha abundance prompted abundance prompted experimental adaptive experimental adaptive management actions management actions including removal of non-including removal of non-native fishnative fish

Melis et al. 2006

ObjectivesObjectives Evaluate Efficacy of Removing Non-native FishEvaluate Efficacy of Removing Non-native Fish

To what extent can we remove non-native fishes To what extent can we remove non-native fishes from a large reach of the Colorado River?from a large reach of the Colorado River?

Evaluate Effect of Non-native Fish Removal on the Evaluate Effect of Non-native Fish Removal on the Population Dynamics of Native FishesPopulation Dynamics of Native Fishes Will humpback chub recruitment increase as a Will humpback chub recruitment increase as a

result of non-native removal?result of non-native removal?

MethodsMethods 2003 to 2006 - 6 trips/year2003 to 2006 - 6 trips/year

Jan, Feb, Mar (Winter)Jan, Feb, Mar (Winter) Jul, Aug, Sep (Summer)Jul, Aug, Sep (Summer)

Sampling Methods:Sampling Methods: ElectrofishingElectrofishing

4-5 pass depletions4-5 pass depletions HoopnettingHoopnetting

Estimate relative Estimate relative abundance of native abundance of native fish (Juveniles).fish (Juveniles).

MethodsMethods

Methods – Data AnalysisMethods – Data Analysis Constructed abundance estimates for rainbow trout using a Constructed abundance estimates for rainbow trout using a

Hierarchical Bayes Removal Model (Dorazio et al 2005).Hierarchical Bayes Removal Model (Dorazio et al 2005). Assumed that site-specific capture probability is drawn Assumed that site-specific capture probability is drawn

from a common Beta distribution.from a common Beta distribution. Prior on capture probability.Prior on capture probability.

Assumed that site-specific abundance is drawn from a Assumed that site-specific abundance is drawn from a common Poisson distribution.common Poisson distribution.

Prior on abundance.Prior on abundance. I used uninformative (Uniform) hyper-prior distributions.I used uninformative (Uniform) hyper-prior distributions.

Model based aggregation of among site dataModel based aggregation of among site data Allows sites with high measurement error to be informed or “shrunk” Allows sites with high measurement error to be informed or “shrunk”

towards the common meantowards the common mean

Results:Results:Efficacy of Removal EffortsEfficacy of Removal Efforts

Results - Electrofishing CatchResults - Electrofishing CatchElectrofishing Species Composition in the LCR Removal Reach

Humpback.ChubFlannelmouth.SuckerBluehead.SuckerSpeckled.DaceCyprinidsCentrarchidsBlack.BullheadChannel.CatfishBrown.TroutRainbow.Trout

0

10

20

30

40

50

60

70

80

90

100

Perc

ent C

ompo

sitio

n by

Num

ber

Jan-

03

Feb-

03

Mar

-03

Jul-0

3

Aug

-03

Sep

-03

Jan-

04

Feb-

04

Mar

-04

Jul-0

4

Aug

-04

Sep

-04

Jan-

05

Feb-

05

Mar

-05

Jul-0

5

Aug

-05

Sep

-05

Jan-

06

Feb-

06

Mar

-06

Jul-0

6

Aug

-06

Electrofishing Catch by Species in the LCR Removal Reach

Humpback.ChubFlannelmouth.SuckerBluehead.SuckerSpeckled.DaceCyprinidsCentrarchidsBlack.BullheadChannel.CatfishBrown.TroutRainbow.Trout

0

500

1000

1500

2000

2500

3000

3500

4000

4500

Tota

l Cat

ch (#

of F

ish)

Results - Electrofishing CatchResults - Electrofishing CatchElectrofishing Species Composition in the LCR Removal Reach

Humpback.ChubFlannelmouth.SuckerBluehead.SuckerSpeckled.DaceCyprinidsCentrarchidsBlack.BullheadChannel.CatfishBrown.TroutRainbow.Trout

0

10

20

30

40

50

60

70

80

90

100

Perc

ent C

ompo

sitio

n by

Mas

s

Jan-

03

Feb-

03

Mar

-03

Jul-0

3

Aug

-03

Sep

-03

Jan-

04

Feb-

04

Mar

-04

Jul-0

4

Aug

-04

Sep

-04

Jan-

05

Feb-

05

Mar

-05

Jul-0

5

Aug

-05

Sep

-05

Jan-

06

Feb-

06

Mar

-06

Jul-0

6

Aug

-06

Electrofishing Catch by Species in the LCR Removal Reach

Humpback.ChubFlannelmouth.SuckerBluehead.SuckerSpeckled.DaceCyprinidsCentrarchidsBlack.BullheadChannel.CatfishBrown.TroutRainbow.Trout

0

500

1000

1500

Tota

l Cat

ch (K

g)

Results - Rainbow Trout AbundanceResults - Rainbow Trout AbundanceRainbow Trout Abundance in the Little Colorado River Removal Reach

020

0040

0060

0080

00

Jan-

03

Feb-

03

Mar

-03

Jul-0

3

Aug

-03

Sep

-03

Jan-

04

Feb-

04

Mar

-04

Jul-0

4

Aug

-04

Sep

-04

Jan-

05

Feb-

05

Mar

-05

Jul-0

5

Aug

-05

Sep

-05

Jan-

06

Feb-

06

Mar

-06

Jul-0

6

Aug

-06

Trip Date

Rai

nbow

Tro

ut A

bund

ance

2003 2004 2005 2006

Results - Rainbow Trout AbundanceResults - Rainbow Trout AbundanceRainbow Trout Abundance in the Little Colorado River Removal Reach

010

0020

0030

0040

0050

0060

00

Jan-

03

Feb-

03

Mar

-03

Jul-0

3

Aug

-03

Sep

-03

Jan-

04

Feb-

04

Mar

-04

Jul-0

4

Aug

-04

Sep

-04

Jan-

05

Feb-

05

Mar

-05

Jul-0

5

Aug

-05

Sep

-05

Jan-

06

Feb-

06

Mar

-06

Jul-0

6

Aug

-06

Trip Date

Rai

nbow

Tro

ut A

bund

ance

2003 2004 2005 2006

UpstreamDownstream

Results - Rainbow Trout Capture ProbabilityResults - Rainbow Trout Capture ProbabilityRainbow Trout Capture Probability in the Little Colorado River Removal Reach

0.0

0.1

0.2

0.3

0.4

Jan-

03

Feb-

03

Mar

-03

Jul-0

3

Aug

-03

Sep

-03

Jan-

04

Feb-

04

Mar

-04

Jul-0

4

Aug

-04

Sep

-04

Jan-

05

Feb-

05

Mar

-05

Jul-0

5

Aug

-05

Sep

-05

Jan-

06

Feb-

06

Mar

-06

Jul-0

6

Aug

-06

Trip Date

Cap

ture

Pro

babi

lity

2003 2004 2005 2006

UpstreamDownstream

Results:Results:Indicators of Native Fish Indicators of Native Fish

Population ResponsePopulation Response

Electrofishing Catch Rate of Humpback Chub in the LCR Removal Reach

01/0

1/03

04/0

1/03

07/0

1/03

10/0

1/03

01/0

1/04

04/0

1/04

07/0

1/04

10/0

1/04

01/0

1/05

04/0

1/05

07/0

1/05

10/0

1/05

01/0

1/06

04/0

1/06

07/0

1/06

10/0

1/06

02

46

8

CPU

E (F

ish/

Hou

r)

Trip Date

Results - Humpback Chub Relative AbundanceResults - Humpback Chub Relative Abundance

Electrofishing CPUE of Flannelmouth Sucker in the LCR Removal Reach

01/0

1/03

04/0

1/03

07/0

1/03

10/0

1/03

01/0

1/04

04/0

1/04

07/0

1/04

10/0

1/04

01/0

1/05

04/0

1/05

07/0

1/05

10/0

1/05

01/0

1/06

04/0

1/06

07/0

1/06

10/0

1/06

05

1015

CPU

E (F

ish/

Hou

r)

Trip Date

Results - Flannelmouth Sucker Relative AbundanceResults - Flannelmouth Sucker Relative Abundance

Electrofishing CPUE of Bluehead Sucker in the LCR Removal Reach

01/0

1/03

04/0

1/03

07/0

1/03

10/0

1/03

01/0

1/04

04/0

1/04

07/0

1/04

10/0

1/04

01/0

1/05

04/0

1/05

07/0

1/05

10/0

1/05

01/0

1/06

04/0

1/06

07/0

1/06

10/0

1/06

02

46

8

CPU

E (F

ish/

Hou

r)

Trip Date

Results - Bluehead Sucker Relative AbundanceResults - Bluehead Sucker Relative Abundance

Thanks!

Background and MotivationBackground and Motivation February 2002, GCMRC proposes a 16 year study to address questions February 2002, GCMRC proposes a 16 year study to address questions

related to providing better management of Sediment related to providing better management of Sediment ANDAND Native Fish. Native Fish.

YearYear Mechanical RemovalMechanical Removal Fluctuating FlowsFluctuating Flows Temperature Control DeviceTemperature Control Device

11 XXXXXX XXXXXX

22 XXXXXX XXXXXX

33 XXXXXX

44 XXXXXX

55 XXXXXX

66 XXXXXX

77

88

99 XXXXXX XXXXXX XXX???XXX???

1010 XXXXXX XXXXXX XXX???XXX???

1111 XXXXXX XXX???XXX???

1212 XXXXXX XXX???XXX???

1313 XXXXXX XXX???XXX???

1414 XXXXXX XXX???XXX???

1515 XXX???XXX???

1616 XXX???XXX???

What Really HappenedWhat Really HappenedYearYear Mechanical RemovalMechanical Removal Fluctuating Fluctuating

FlowsFlowsTemperature Control DeviceTemperature Control Device

1 (2003)1 (2003) XXXXXX XXXXXX ““Naturally Elevated Temp”Naturally Elevated Temp”

2 (2004)2 (2004) XXXXXX XXXXXX ““More Naturally Elevated Temp”More Naturally Elevated Temp”

3 (2005)3 (2005) XXXXXX XXXXXX ““Even More Naturally Elevated Temp”Even More Naturally Elevated Temp”

4 (2006)4 (2006) XXXXXX ““Naturally Elevated Temp”Naturally Elevated Temp”

5 5 (2007)(2007) (Non-natives in low abundance)(Non-natives in low abundance) ““Likely Elevated Temp”Likely Elevated Temp”

66 ???????????????? ???????????????? ????????????????

77 ???????????????? ???????????????? ????????????????

88 ???????????????? ???????????????? ????????????????

99 ???????????????? ???????????????? ????????????????

1010 ???????????????? ???????????????? ????????????????

1111 ???????????????? ???????????????? ????????????????

1212 ???????????????? ???????????????? ????????????????

1313 ???????????????? ???????????????? ????????????????

1414 ???????????????? ???????????????? ????????????????

1515 ???????????????? ???????????????? ????????????????

1616 ???????????????? ???????????????? ????????????????