Prepared by:

Ron Kegerries 1, Brandon Albrecht 1, Ron 

Rogers1, W. Howard Brandenburg 2, Adam L. 

Barkalow 2, Harrison Mohn1, Mark 

McKinstry3, Brian Healy 4, James Stolberg 5, 

Emily Omana Smith 4

1 BIO-WEST, Inc.;

2 American Southwest Ichthyological Researchers, LLC;

3 U.S. Bureau of Reclamation, Upper Colorado Region;

4 U.S. National Park Service;

5 Lower Colorado River Multi-Species Conservation 

Program

Glen Canyon Dam Adaptive 

Management Program – March 2018

2015 ANNUAL REPORT

Razorback Sucker Xyrauchen texanus Research and Monitoring in the 

Colorado River Inflow Area of Lake Mead and the Lower Grand Canyon,

Arizona and Nevada
Objectives

• Monitoring the Colorado River 

Inflow (CRI) 

– Same methods since 2010

• Determine Razorback Sucker 

presence and habitat use in Grand 

Canyon (GC)

– Larval and small-bodied fish 

community sampling within the GC

• Assess reproduction and distribution

– GC telemetry

• Explore linkages between Lake 

Mead and GC

Razorback Sucker Xyrauchen texanus Research and Monitoring in the Colorado River Inflow Area of Lake 

Mead and the Lower Grand Canyon, Arizona and Nevada
Colorado River Inflow (CRI)

Razorback Sucker Xyrauchen texanus Research and Monitoring in the Colorado River Inflow Area of Lake 

Mead and the Lower Grand Canyon, Arizona and Nevada

Photo credit: USBR
2017 Adult Catch (CRI)

Razorback Sucker Xyrauchen texanus Research and Monitoring in the Colorado River Inflow Area of Lake 

Mead and the Lower Grand Canyon, Arizona and Nevada

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

0.18

0.20

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Mean Razorback Sucker Captures 

(Ln[#fish/hour+1])

Year

Virgin River/Muddy River Inflow Area

Echo Bay

Las Vegas Bay

Colorado River Inflow

• 12 Razorback Suckers

– 5 new, wild (1 was juvenile)

– 2 recaps from Overton Arm

– 1 sonic-tagged LGC recap
0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

2010 2011 2012 2013 2014 2015 2016 2017

Mean Larval Razorback Sucker 

Captures (Ln[#larvae/lightminute+1])

Year

Virgin River/Muddy River inflow area

Echo Bay

Las Vegas Bay

Colorado River inflow area

2017 Larval Catch (CRI)

Razorback Sucker Xyrauchen texanus Research and Monitoring in the Colorado River Inflow Area of Lake 

Mead and the Lower Grand Canyon, Arizona and Nevada

• Active and passive sampling:

‒ 6 RBS larvae

‒ 3 FMS larvae 
9.05 (5.76-13.9)

8.1 (3.78-16.54)

Echo 

Bay

Virgin River/Muddy River 

inflow

Las Vegas 

Bay

Colorado 

Inflow

Movement of RBS in Lake Mead

Razorback Sucker Xyrauchen texanus Research and Monitoring in the Colorado River Inflow Area of Lake 

Mead and the Lower Grand Canyon, Arizona and Nevada

Overton 

Arm

Mohn et al. (2016)
Small-bodied and Larval Fish Surveys

Razorback Sucker Xyrauchen texanus Research and Monitoring in the Colorado River Inflow Area of Lake 

Mead and the Lower Grand Canyon, Arizona and Nevada

a~f.1,'l!.1'11E.N T OfJl'll:/N7f/t. 

~ ......... ~ 

--~-
GC Survey Summary (2014–2017)

Year Study area Study Period GRTS 

Sites

Implanted

Razorback

Sucker

Larval 

Razorback 

Sucker

2014 100 river miles

Lava Falls–

Pearce Ferry

Apr–Sep n=40 n=9

above Lava Falls 

Rapid

n=459

2015 100 river miles

Lava Falls–

Pearce Ferry

Mar–Sep n=40 n=81

2016 191 river miles

Bright Angel 

Creek–Pearce 

Ferry

Mar–Sep n=56 n=10

Diamond Creek

n=46

2017 191 river miles

Bright Angel 

Creek–Pearce 

Ferry

Mar–Sep n=56 n=27

Razorback Sucker Xyrauchen texanus Research and Monitoring in the Colorado River Inflow Area of Lake 

Mead and the Lower Grand Canyon, Arizona and Nevada
Sampling Localities in Grand Canyon

= GRTS site 

River Mile

UT

Razorback Sucker Xyrauchen texanus Research and Monitoring in the Colorado River Inflow Area of Lake 

Mead and the Lower Grand Canyon, Arizona and Nevada
Methods

Razorback Sucker Xyrauchen texanus Research and Monitoring in the Colorado River Inflow Area of Lake 

Mead and the Lower Grand Canyon, Arizona and Nevada

Larval Fish Sampling

• Small fine mesh seine

• low velocity habitats

• four hauls per site

Small-bodied Fish Sampling

• 10’ and 15’ seine

• diverse habitats

• ~10 hauls per site

Telemetry

• Active

• Passive (n=20 SURs, 

every 10 miles)
Age-0 Monthly Captures

Flannelmouth Sucker (CATLAT)

Bluehead Sucker (CATDIS)

Razorback Sucker (XYRTEX)

Humpback Chub (GILCYP)

Speckled Dace (RHIOSC)

Razorback Sucker Xyrauchen texanus Research and Monitoring in the Colorado River Inflow Area of Lake 

Mead and the Lower Grand Canyon, Arizona and Nevada
2017 Age-0 Fish Captures – March

9–17 March 2017 

GRTS segments: 54 

Effort: 1,993.4 m2

Razorback Sucker Xyrauchen texanus Research and Monitoring in the Colorado River Inflow Area of Lake 

Mead and the Lower Grand Canyon, Arizona and Nevada
2017 Age-0 Fish Captures – April

8–13 April 2017 

GRTS segments: 56 

Effort: 2,011.6 m2

Razorback Sucker Xyrauchen texanus Research and Monitoring in the Colorado River Inflow Area of Lake 

Mead and the Lower Grand Canyon, Arizona and Nevada
2017 Age-0 Fish Captures – May

19–24 May 2017 

GRTS segments: 56 

Effort: 2,017.7 m2

Razorback Sucker Xyrauchen texanus Research and Monitoring in the Colorado River Inflow Area of Lake 

Mead and the Lower Grand Canyon, Arizona and Nevada
2017 Age-0 Fish Captures – June

14–19 Jun 2017 

GRTS segments: 56 

Effort: 1,976.5 m2

Razorback Sucker Xyrauchen texanus Research and Monitoring in the Colorado River Inflow Area of Lake 

Mead and the Lower Grand Canyon, Arizona and Nevada
2017 Age-0 Fish Captures – July

11–17 Jul 2017 

GRTS segments: 56 

Effort: 1,978.3 m2

Razorback Sucker Xyrauchen texanus Research and Monitoring in the Colorado River Inflow Area of Lake 

Mead and the Lower Grand Canyon, Arizona and Nevada
2017 Age-0 Fish Captures – August

16–23 Aug 2017 

GRTS segments: 56 

Effort: 1,990.6 m2

Razorback Sucker Xyrauchen texanus Research and Monitoring in the Colorado River Inflow Area of Lake 

Mead and the Lower Grand Canyon, Arizona and Nevada
Back-calculated Hatching Dates

Hatch Dates: 23 February–18 May 2017

Razorback Sucker Xyrauchen texanus Research and Monitoring in the Colorado River Inflow Area of Lake 

Mead and the Lower Grand Canyon, Arizona and Nevada
Back-calculated Hatching Dates

Hatch Dates: 23 February–18 May 2017

Mean daily water temperature (oC)

Razorback Sucker Xyrauchen texanus Research and Monitoring in the Colorado River Inflow Area of Lake 

Mead and the Lower Grand Canyon, Arizona and Nevada
0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

March April May June July August September

Mean CPUE (Ln[#/m2+1]

Trip Month

Native Nonnative

0.000

0.125

0.250

0.375

0.500

0.625

0.750

0.875

1.000

1.125

88.698.7

103.5104.8110.6112.8115.4122.2123.6125.1127.3131.0132.8134.8137.1139.6144.8148.9153.8165.0167.7168.6172.6174.8176.9177.3177.7178.5180.5182.0183.3184.5186.6192.5194.6197.0200.1205.0206.4208.8216.6220.1221.0227.1230.7236.7238.7241.9243.0248.7252.7255.2263.6269.0269.9277.4279.0

Mean CPUE (Ln[#/m2+1]

River Mile

Native Nonnnative

2017 Small-bodied Sampling (GC)

Razorback Sucker Xyrauchen texanus Research and Monitoring in the Colorado River Inflow Area of Lake 

Mead and the Lower Grand Canyon, Arizona and Nevada

Havasu Creek

Shinumo

Diamond Creek

Creek
0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

March April May June July August September

Mean CPUE (Ln[#/m2+1]

Trip Month

Native

Humpback Chub

Bluehead Sucker

Flannelmouth Sucker

Speckled Dace

YOY Sucker

2017 Small-bodied Sampling (GC)

Razorback Sucker Xyrauchen texanus Research and Monitoring in the Colorado River Inflow Area of Lake 

Mead and the Lower Grand Canyon, Arizona and Nevada
0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

88.6

103.5109.2112.8122.2125.1131.0132.8134.4137.1144.0148.9165.0168.6174.8177.3178.2179.5182.0184.5192.5197.0205.0208.8220.1227.1236.7241.9248.7252.7263.6269.9279.0

Mean CPUE (Ln[#/m2+1]

River Mile

Small-Bodied HBC Captures 2017 

(all trips combined)

n=930

19–282 mm TL

Razorback Sucker Xyrauchen texanus Research and Monitoring in the Colorado River Inflow Area of Lake 

Mead and the Lower Grand Canyon, Arizona and Nevada
0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Above DC Below DC Above DC Below DC Above DC Below DC

1992-1995 2004-2006 2014-2016

Percent of Capture

Sampling Period and River Segment

Native Nonnative

• Valdez et al. (1995), Ackerman et al. (2005), Kegerries et al. (2014–2017)

Small-bodied Sampling (GC)

Razorback Sucker Xyrauchen texanus Research and Monitoring in the Colorado River Inflow Area of Lake 

Mead and the Lower Grand Canyon, Arizona and Nevada
• Critical to monitor movement and improve sampling efficiency

• Since 2013 n=46 sonic tagged fish released 

Telemetry-Tagged Fish

Razorback Sucker Xyrauchen texanus Research and Monitoring in the Colorado River Inflow Area of Lake 

Mead and the Lower Grand Canyon, Arizona and Nevada
2010–2016 Movement Patterns

0

50

100

150

200

250

300

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Number of Days Contacted

Month

CRI

Grand Canyon

• Four types of movement

• 70% remain within stocking 

habitat

• Most movement occurs 

during the spring and 

summer

Razorback Sucker Xyrauchen texanus Research and Monitoring in the Colorado River Inflow Area of Lake 

Mead and the Lower Grand Canyon, Arizona and Nevada
Razorback Sucker Xyrauchen texanus Research and Monitoring in the Colorado River Inflow Area of Lake 

Mead and the Lower Grand Canyon, Arizona and Nevada

South Cove 

Lake Mead

Pearce Ferry Rapid Bright Angel 

Creek

Spencer Creek

Lava Falls

2014-2017 Diamond Creek

Upstream

Downstream

Up- and Downstream 

Movement Patterns
2017 Science Panel Report

• Do not force augmentation (i.e., 

stocking) of Razorback Sucker. 

• Continue ongoing work with 

Razorback Sucker at the Colorado 

River Inflow Area and western Grand 

Canyon. 

• Expand fish surveys for Razorback 

Sucker, in the lower Grand Canyon and 

investigate larval fish to get evidence 

of spawning and use of river.

• Integrate all habitat, fish, and food 

base studies in the Grand Canyon and 

the Colorado River Inflow Area of Lake 

Mead. 

Razorback Sucker Xyrauchen texanus Research and Monitoring in the Colorado River Inflow Area of Lake 

Mead and the Lower Grand Canyon, Arizona and Nevada
Razorback Sucker Conclusions

Razorback Sucker Xyrauchen texanus Research and Monitoring in the Colorado River Inflow Area of Lake 

Mead and the Lower Grand Canyon, Arizona and Nevada

• All life stages present at the CRI (8th year).

• Larvae documented in Grand Canyon downstream of 

Havasu Creek.

• Native fishes dominate the fish community of the GC.

• Movement of Razorback Sucker occurs between Grand 

Canyon, CRI, and Lake Mead.

• Hypothesize that lentic and lotic habitats cumulatively 

facilitate Razorback Sucker recruitment.
---- ·- - --., 

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