Anya N. Metcalfe1,2, Theodore A. Kennedy1

, 

Jeffrey D. Muehlbauer1, Jane Marks2

1U. S. Geological Survey, Southwest Biological Science Center, 

Grand Canyon Monitoring and Research Center

2Northern Arizona University, Biological Sciences Department

Photo: Ryan Moseley
Tasty

Why aquatic insects?

Ephemeroptera

mayflies

Trichoptera

caddisflies

Plecoptera

stoneflies

Bioindicators

“EPT”
What are the basinwide trends of aquatic insect 

species richness and abundance?
Colorado River Basin

NEVADA 

BAJA 

CALIFORNIA 

WYOMING 

NEW MEXICO 
Field Methods
Field Methods
Field Methods
Light Trap Sample 

Distribution 2015 - 2016

Temporal Coverage

2,562 samples 

from 1,657 unique sites

Preliminary data, do not cite.

Cf) 

Q) 

0.. 

E 

(lj 

Cf) 

:i:t: 

600 

400 

200 

0 

2 3 4 5 6 7 

Month 

8 9 

- 10 11 12 

Year 

• 2015 

. 2016 

0km 50km 100km t 

• 2015 samples 

0 2016 samples 

Lotic 

c:::::::::::J Len tic 

ontenelle 

~ ervo1r 

Green 

River 

Uinta 

Basin 

ning Gorge 

rvoir 

~ 

Yampa River 

Nav j 

L ~ M 
Dam

Richness 

greatest in 

upper Green 

River

Preliminary data, do not cite.
Dam

Preliminary data, do not cite.
y = -1.2x + 38.8 

r

2=0.48

Richness 

greatest at 

high latitudes

Preliminary data, do not cite.
Distance to Lake Mead (KM)

Light trap catch rate (# individuals/hr)

FGD Powell Mead Font Uinta

Insect abundance peaks 

below tailwaters

Preliminary data, do not cite.
What environmental variables best describe the 

occupancy and abundance of aquatic insects in the 

Colorado River Basin?

Hydropsyche sp. 
Hydropsyche
Hydropsyche spp. in light traps

• 79% of light trap samples contained 

caddisflies (n = 2039)

• 23% of light trap samples contained 

Hydropsyche (n = 599)

• Collected 6 species of Hydropsyche

• 18,527 individual Hydropsyche

• 97% identified to species (n = 17,889)

Preliminary data, do not cite.
Upper Green River

& Yampa

G2

Grand

Canyon

0.01 0.50

Preliminary data, do not cite.
• Latitude

• Day of year

• Sampling site

• Distance from dam

• Mean daily discharge

• Daily change in stage height

• Mean water temperature

• Range in annual water temperatures

Top models describing occupancy and abundance of Hydropsyche spp. in the Colorado River Basin

Species Occupancy Detection Abundance

Hydropsyche occidentalis λ (MeanT), p (Stage + Stage2 + Lat + Lat2 + Day + Day2) Stage + Stage2 + MeanT + MeanT2 + Day + Day2 + (1|Site)

Hydropsyche oslari λ (Stage), p (Sites + Lat + Lat2) Stage + Stage2 + Lat + (1|Site)

λ (RangeT), p (Sites + Lat + Lat2)

Hydropsyche confusa λ (.), p (RangeT + RangeT2 + MeanT + MeanT2) Lat + Lat2 + RangeT + RangeT2 + MeanT + MeanT2 + (1|Site)

λ (.), p (Lat + Lat2 + RangeT + RangeT2)

λ (.), p (Lat + Lat2 + MeanQ + MeanQ2)

Preliminary data, do not cite.
• Latitude

• Day of year

• Sampling site

• Distance from dam

• Mean daily discharge

• Daily change in stage height

• Mean water temperature

• Range in annual water temperatures

Top models describing occupancy and abundance of Hydropsyche spp. in the Colorado River Basin

Lat Day Site Mean Q

Stage 

change

Mean

Temp

Range

Temp

H. occidentalis

H. oslari

H. confusa

11.7 °C

± 1.4 °C

11.1 °C

± 1.3 °C

12.2 °C

± 0.6 °C

11.0 °C

± 5.9 °C

20.1 °C

± 3.8 °C

23.6 °C

± 1.8 °C

Preliminary data, do not cite.
Staff gage Typical USGS streamgage

nn 

I loor 

Wt r urf 
“intertidal zone”

M. Kaplinski
Stage change & Hydropsyche spp.

1 species

Low abundance

Both species

High abundance

Preliminary data, do not cite.
Daily stage change 

fluctuation in Glen and 

Grand Canyons range from 

1.3 to 2 feet

Stage change & Hydropsyche spp.

1 species

Low abundance

All species

High abundance

Preliminary data, do not cite.
Is the dispersal of aquatic insects

in the Colorado River Basin 

limited by network connectivity?

Hydropsyche oslari

mtDNA CO1 
Hydropsyche oslari

mtDNA CO1 

5% step-wise 

difference (33/212)

Preliminary data, do not cite.

LEGEND 0.92 

o Flaming Gorge 

• Lodore Canyon I 

• Yampa River 

o Whirlpool Canyon 

• Gunnison River 0.9 

• Grand Canyon East I 

o Grand Canyon West Upper bas in • Voucher 

8.0 

0.98 

•• :..< 

-~~," - -· ';'~, a . 

~ 0.73 

~ ..... ~ !"_~\. 

~---- u~ 

I U.'JX 

I 

\.._ 

I ,--

0.99 

Grand Ca nyon 0.99 

l 

Hydropsyche spp. 

1 

-

; 

; 

; 

0.96 

I 

0.79 

0.95 -

0.911 

r 

I I 

1 

. 001! ..ir. 

! -p 

. ~ t 0.95 t 

:~, 

. 

fftd ) 

LC;~ } 

~. . ~ ' ~ : 

"'l~ . , I .9 I , 

I 

. 

0.9'Z I "} 

0.99 ) ? 

I 

~. : 

; 

; 

. 

·; J ~ -

0. 

~ ' t 

t 

HYOS11 HS 

HYOS12 HS 

HYOS1S HS 

HYOS14 H7 

HYOS19 HS 

HYOS20 HS 

HYOS16 H9 

HYOS94 H37 

RBCAD-0076 

HYOS90 H34 

HYOS93 H34 

HYOS91 H36 

HYOS01 Hl 

HYOS02 Hl 

HYOS04 Hl 

HYOSOS Hl 

HYOS06 Hl 

HYOS07 H3 

HYOS08 Hl 

HYOS09 H4 

HYOS10 Hl 

HYOS61 Hl 

HYOS62 Hl 

HYOS63 Hl 

HYOS64 H29 

HYOS6S Hl 

HYOS71 H30 

HYOS73 Hl 

HYOS7S Hl 

HYOS76 Hl 

HYOS74 H31 

HYOS72 H30 

HYOS77 H30 

HYOS78 Hl 

HYOS79 Hl 

HYOS80 H32 

HYOS89 H33 

HYOS9S H33 

HYOS03 H2 

HYOS13 H6 

HYOS92 H36 

HYOS96 H38 

RBCAD-0070 

HYOSSO H28 

HYOS4S H2S 

HYOS2S H12 

HYOS36 H18 

HYOS48 H26 

HYOS38 H19 

HYOS39 H20 

HYOS47 H13 

HYOS46 H13 

HYOS44 H24 

HYOS43 H23 

HYOS3S H17 

HYOS30 H14 

HYOS41 H22 

HYOS37 H13 

HYOS33 H13 

HYOS31 H13 

HYOS29 H13 

HYOS34 H16 

HYOS22 Hll 

HYOS21 HlO 

HYOS40 H21 

HYOS49 H27 

HYOS32 HlS 

OSRMCAD-0241 

OSOFCAD-0662 

SGABR2S03- 12 

DRCAD392- 10 

NBTRI719-08 

OSOFCAD-1000 
Haplotype analysis

“SNP” singlenucleotide 

polymorphism

Upper 

Basin

Grand

Canyon

Preliminary data, do not cite.
Many hands make light (traps) work

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Acknowledgements

Ali Ingram

Brece Hendrix

Dallana Garcia-Pena

David Goodenough 

Eric Kortenhoeven

Megan Daubert

Morgan Ford

Moriah Evans

Tom Quigley