Relocated Unionid Survival, 15 years later, Wolf River, Wisconsin Heidi Dunn, Ecological Specialists, Inc. Lisie Kitchel, Wisconsin Department of Natural Resources
Relocated Unionid Survival,
15 years later,
Wolf River, Wisconsin
Heidi Dunn, Ecological Specialists, Inc.
Lisie Kitchel, Wisconsin Department of Natural Resources
Few Long-Term Monitoring Studies
following Relocation
• Where do they go?
• How long do they survive?
• Is the native community affected?
• Do impact areas recolonize?
Wolf River, Wisconsin
• 219 miles long
– 3700 sq miles
– 11 counties
– Menominee Indian Res.
– Forested wetland/ag land
– North Hills/Plains
– Northern Lakes/Forests
• Headwaters-Forest Co.
– Trout stream
– Series of Dells
– White water rafting
• 2 Dams up of Shawano
• South of Shawano
– Free flowing
– 93 miles to Lake Poygan
– Fox River/Lake Winnebago
– Lake Sturgeon spawning
– One of two populations of E.triquetra
Shawano
• Shawano County
– 29 Species
• 2 Wisconsin Endangered
– Epioblasma triquetra
– Lampsilis teres
• 3 Wisconsin Threatened
– Alasmidonta viridis
– Simpsonaias ambigua
– Tritogonia verrucosa
• 5 Wisconsin Special Concern
– Alasmidonta marginata
– Elliptio complanata
– Pleurobema sintoxia
– Quadrula quadrula
– Truncilla donaciformis
– High density areas (20+/m2)
– Dominant Species• A. ligamentina and T. truncata
High Quality Unionid Communities
2010 Wolf River Relocation/Monitoring
• 1995 STH 29 Relocation
– 26,377 unionids removed
– 21 species
– About 8/m2
– 23,111 General Relocation Area
– 290 E. triquetra, A. marginata, and
T. verrucosa in Grids
– 1996 and 1997 monitoring
• 2010 STH 22 Relocation
– 550m Upstream of STH 29
– 50m Upstream of Rel. Area
1995 STH 29 Relocation
– General Relocation Area
• Added 7.7/m2
• Resident 12.2/m2 (±2.4)
• 63% increase
– Grids
• Grid A
– Added 120 unionids (2/m2)
– 15.6/m2 residents
– 13% increase
• Grid B
– Added 170 unionids (2/m2)
– 10.0/m2 residents
– 20% increase
1996/97 STH 29 Monitoring
Year Relocated Native Total
1995 10.4 ± 3.1A 12.2 ± 2.4A 22.2 ± 4.1A
1996 6.0 ± 1.7A 15.2 ± 3.3A 21.2 ± 4.2A
1997 6.8 ± 1.6A 10.8 ± 2.0A 17.5 ± 2.8A
General Relocation Area Density Similar 1995-1997
Sample size= 45, 0.25m2 samples
Different letters within a column indicate a significant difference (ANOVA, p<0.05)
T&E Species Recovery/Survival
1995 1996 1997
A. marginata 7 2 1
E. triquetra 110 40 (1) 56
T. verrucosa 2 2 1
Total live 119 44 58
Total shells 0 1 0
No. samples 60 37 30
No./m2 2 1.3 ± 0.3 0.7 ± 0.4
% Recovery 78% 50%
% Survival 98% 100%
Grid A Recovery/Survival
No. live (no. shells)
1995 1996 1997
A. marginata 17 6 8
E. triquetra 152 50 (3) 94 (3)
T. verrucosa 2 0 1
Total live 171 56 103
Total shells 0 3 3
No. samples 86 52 36
No./m2 2 1.1 ± 0.2 0.9 ± 0.4
% Recovery 69% 62%
% Survival 95% 97%
Grid B Recovery/Survival
No. live (no. shells)
2010, monitoring 15 year later
• STH 29 bridge
– Habitat
– Recolonization
• Density in General Relocation Area
• Movement out of General Relocation Area
• Survival/Movement in T&E Grids
Upstream Migration
• STH 22 collection
– 9472 unionids, 20 species
– Recaptured 14 live and 1 shell
• A. ligamentina: 8 live; 1 shell
• E. dilatata: 1 live
• L. cardium: 2 live
• L. recta: 1 live
• P. alatus: 2 live
• Moved 50 to 250m upstream!
Growth Since 1995
Growth Since 1995
STH 29 Relocation Area
• 2010
– 20 0.25m2 Quadrats
– 5 live A. ligamentina
– 1 live L. costata
– 1 live P. alatus
– 5 marked shells
– Density 1.4/m2 ± 0.9
– 4200 (±2700) still alive
– 18% of 23,111
– Many likely died of old age
• 1995
– Average age 12.5 years
– 5% less than 5 years old
2010 STH 29 Monitoring
Year Relocated Native Total
1995 10.4 ± 3.1A 12.2 ± 2.4AB 22.2 ± 4.1A
1996 6.0 ± 1.7A 15.2 ± 3.3A 21.2 ± 4.2A
1997 6.8 ± 1.6A 10.8 ± 2.0AB 17.5 ± 2.8A
2010 1.4 ± 0.9B 7.0 ± 3.0B 8.4 ± 3.1B
Native density not affected; A few relocated unionids alive
Sample size 1995, 1996, 1997 = 45, 0.25m2 samples; 2010= 20, 0.25m2 samples
Different letters within a column indicate a significant difference (ANOVA, p<0.05)
T&E Species Grids Still In Place
T&E Species Grid A 1997-2010
T&E Species Grid B 1997-2010
Epioblasma triquetra 1995-2010
Length (mm)
Sex Status ID Age 1995 1995 2010 Diff
M L 633 17 53 59 6
M L 760 11 46 61 15
M L 795 10 47 57 10
M L 789 12 54 63 9
M L 772 10 48 57 9
M L 731 15 53 56 3
M WD 685 13 50 55 5
STH 29 Bridge Unionids 2010
• Shallow run
– Aquatic vegetation
– Mostly stable substrate
– Scour holes near piers
– Depositional areas
• Unionids
– 20 0.25m2 Quadrats
– No marked unionids
– 10 species (no E. triquetra)
– 24% ≤5 years old
– 5.0/m2 (±2.8) vs 8/m2 in 1995
• Right 0
• Middle 4.4/m2
• Left 11.2/m2
What Did We Learn?
• Relocation Methods
– Found relocation areas
– Grids/Markers still in place
– Recovered animals
– Track growth
– Track movement
• Survival after 15 years
• No permanent increase in density
• Considerable upstream movement
• Habitat not permanently lost due to construction
• Epioblasma triquetra live over 30 years!
Acknowledgements
Funding provided by Wisconsin Department of Transportation
Field Assistance:
ESI staff-Eric Rahm, Nathan Badgett, Kendall Cranney,
Jeff Garner, Dan Scoggin, Heidi Dunn
WisDOT-Roseanne Meer, Janet Smith and staff
WisDNR-Allan Stranz, Randy Piette, Lisie Kitchel and staff