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4/2/14
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Impacts of Climate Change, Human Land Use, and Mercury Contamina;on on Southern Appalachian Plethodon;d Salamanders
M. Kevin Hamed
Ph.D. Disserta;on Defense
Amphibian Declines
33% of Amphibians and 47% of salamanders are threatened globally
IUCN 2008
6th Mass Extinction Wake & Vredenburg 2008
• Habitat Loss • Diseases & Pathogens
• Climate Change
• Chemical Contamination • Over-exploitation
• Synergistic Interactions
Center for Diversity
(Young et al. 2004)
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Temporal & Spatial Changes of Mercury Contamination of Black-bellied
Salamanders (Desmognathus quadramaculatus)
Mercury
• Reduce reproductive success • Impair neurological function • Alter hormone production Driscoll et al. 2007
6600 metric tons 66% Anthropogenic Sources
~50% Power Plants
US emissions peaked 1970s
Effects to Humans & Wildlife:
LC50 =103 µg/L
Ambystoma opacum
Amphibian Declines & Mercury
Eurycea bislineata
• Decreased responsiveness & capture speed
Burke et al. 2010
Sparling et al. 2000
> Bank et al. 2005
Southern Appalachian Void
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Temporal Changes Museum Specimens
Berg et al. 1966
100 years
Hill et al. 2010 40 years
Other Fish Studies: Costa et al. 2006; Kamimura 1975; Kelly et al. 1975; Gibbs et al. 1974; Barber & Cross 1972
Fredrick et al. 2004
1910 - 1980
Amphibians ?
Objectives
I. Non-lethal Sampling
II. Spatial Comparison
III. Efficiency of Museum Specimens IV. Temporal Comparisons
Study Area
Whitetop Mt. (Grayson, Smyth, Washington Co. VA)
Big Branch • North Slope (945 – 1280 m)
Whitetop Creek • South Slope (1158 – 1554 m)
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Whitetop Mountain
150 cm of wet precipitation
50 cm cloud water deposition
33%
Mean pH of cloud water 3.49 (minimum 2.59) • Fossil Fuels Major Contributor (Vong et al. 1991)
Black-bellied Salamander Desmognathus quadramaculatus
Photo by Steve Tilley USGS 2010
• Largest Desmognathine salamander • Long-lived 13+ years • 3.5 year aquatic larval period (Organ 1960)
(Bruce 1988)
= Petranka et al. 1998
Apex Predator
Larvae: 82% Aquatic Inverts
Adults: 36 % Aquatic Inverts
(Davic 1991)
22% >1 meter from stream (Peterman et al. 2008)
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Tissue Collection & Preparation
Big Branch – September 2011 Whitetop Creek – June/July 2012
Tail & Liver Samples
Freeze Dried – 48 hours
Sawyer Environmental Chemistry Laboratory
Effects of Preservation
Tissue Collected at Day: 40 80 120 160
UM Preservation Protocol: • 7 Days 10% Buffered Formalin • 2 Days of Water Rinse • 65% Ethanol
30 salamanders – Big Branch
Museum Specimens Dr. James Organ (1957-59)
Elevational Transects
Each specimen identified
• March 2010 & June 2012 • Tail samples collected & processed
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Hill et al. 2010; Rimmer et al. 2010; Blackwell and Drenner 2009; Bergeron et al. 2007; Haynes et al. 2006; Pennuto et al. 2005; Sarica et al. 2004; Boylan et al. 1996
Mercury Analysis EPA Method 7473 DMA-80 (Milestone Inc.)
Thermal decomposition Amalgamation Atomic Absorption
(Bergeron et al. 2010) • Water • Soil • Invertebrates • Fish
Mercury Analysis Detection Limits: 1.00 – 100.29 ng
Replicate Sample Analyses: 3.87 ± 0.34 % (n=42)
Standard Reference Material Dogfish Muscle – National Research Council of Canada
Cell 1: 98.44 ± 0.44 % (n=42) Cell 2: 97.39 ± 0.67 % (n=17)
Results: Non-lethal Collection
(rs = 0.834, P < 0.01)
Ratio of Liver:Muscle Tissue (3.51 – 16.93) > 1
(Sorensen 1991)
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Results: Aspect Comparison 95% CI
N
S
P < 0.001
Atmospheric Deposition
EPA Station 1994-9
50.9 % 6.8 %
26.4 % 15.9 %
500-3,400 MW (EPA 2011)
26
12 10
11
Results: Elevation Comparison
95% CI
P < 0.03
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Comparison to Other Sites Tail Samples:
~200 ng/g (Bergeron et al. 2010)
110 ng/g (Rimmer et al. 2010)
Contaminated Site - VA
Vermont – Elevated Deposition
Mean: 134 ng/g (north slope only 188 ng/g)
Liver Samples:
269 – 544 ng/g ww Everglades (Ugarte et al. 2005)
1,228 ng/g Caddo Lake TX (Chumchal et al. 2011)
68 – 4,136 ng/g; Mean: 2,784 ng/g (17 – 1,034 ng/g ww)
Results: Preservation Effects
8 - 12%
P = 0.837
Temporal Comparison
(Bhavsar et al. 2010)
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Summary • Tail tissue provides a valid non-lethal sampling
method
• Mercury uptake in black-bellied salamanders is ongoing
• Mercury concentrations are greater on the northern slope and at higher elevations
• Museum specimens may provide an accurate measurement of historical mercury contamination
• Mercury concentrations in black-bellied salamanders have decreased since the 1950s on Whitetop Mt.
Changes in Salamanders Distributions Along an Elevational Gradient In the Mt.
Rogers National Recreation Area
Climate Change NOAA 2012 • 2003 – 2012 warmest on record
1.06 °C since 1880 • Past 50-years > of past 1300 IPCC 2007 Shifting Range Limits:
• Plants • Invertebrates • Fish • Amphibians • Reptiles • Birds • Mammals
Comte and Grenouillet 2013 ; Kopp and Cleland 2013; Tingley and Beissinger 2013; Chen et al. 2011; Sinervo et al. 2010; Rovito et al. 2009; Moritz et al. 2008
• 41% have shifted • 6.1 km per decade
Parmesan 2006
~ 50%
Tingley et al. 2012
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Atelopus sp.
Amphibian & Climate Change
Costa Rica
Pounds et al. 2004
Bufo periglenes
• 64% Breeding earlier (up to 59 days)
Yiming et al. 2013
Indirect Effects:
• Increased competition
Yellowstone NP
Patala et al. 2009
Lithobates luteiventris
Bolitoglossa rostrata
(Rovito et al. 2008)
Salamanders & Climate Change
What about Southern Appalachia?
Historic Salamander Dataset Dr. James & Della Organ
Organ 1960, 1990, 1991
• Elevational Transects (914 – 1707 m)
• 1957-59 & 1990-91 • Sampling intervals 30.5 m (100’)
• Mt. Rogers National Recreation Area
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Objectives I. Document salamander distribution
changes since the 1950s & 1990s
II. Examine regional weather patterns to determine potential impact
Study Area Beech Mt.
945 – 1494 m
(Grayson, Smyth, Washington Co. VA)
Bluff Mt. 1097 – 1490 m
Whitetop Mt. 1158 – 1676 m
15 Plethodontid salamander
species
Sampling
Whitetop Ck & Dells Br. 2009 - 2011
(2008 – 2011) 10 transects
5m → ← 5m
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Detection
!⌧ ?
Detection/Occupancy Modeling
1 hour 1 hour
Imperfect detection leads to false range changes
Moritz et al. 2008; Tingley and Beissinger 2009
Overestimate extinctions by 56% Kery 2006
Necessary for historical comparisons
• Modeled current detection and applied to historical data Tingley and Beissinger 2009
• Modeled occupancy corrected for imperfect detection
Regional Climate • Absence of Whitetop historic climate data
• NOAA since 1948
73 km SW
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Results: Distribution Changes Mean Midpoint Changes:
1950s = 7.6 m (1.5 m / decade) 1990s = 9.6 m (4.9 m / decade)
11.9 m Chen et al. 2011 Meta-analysis Moths (Boreno) 15.9 m Chen et al. 2009
Fish (France) 13.9 m Comte and Grenouillet 2013
Herpetofauna (Madagascar) 15 – 51 m Raxworthy et al. 2008
Median: = 15.2 m (3.0 m) = 0 m
Southern Appalachians Plants 24 m Lenori et al. 2008
Stoneflies 29 m Sheldon 2012
Results: Distribution Changes Lower Range Limits
1950s: 16.7%
25.0%
Upper Range Limits
1950s: 8.3%
41.7%
1990s: 16.7% 8.3%
1990s: 0.0% 41.7%
50% Birds Tingley et al. 2012
13.3% Small Mammals 26.7 %
Rowe et al. 2010
25% Small Mammals 25 %
Rowe et al. 2010
Weller’s salamander
1300
1400
1500
1600
1950s Recent 1990s Recent
Elev
atio
n (m
)
Sampling Years
30 m
61 m
Median Range Limit Changes
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0
0.2
0.4
0.6
0.8
1
914 1036
1158 1280
1402 1524
1646
Spec
ies
Occ
upan
cy (ψ
)
Elevation (meters)
Occupancy Recent
Occupancy Historical
Weller’s salamander
1300
1350
1400
1450
1500
1550
1990s Recent
Elev
atio
n (m
)
Survey Years
24.5 m
Range Midpoints
Yonahlossee salamander
1050
1150
1250
1350
1450
1950s Recent 1990s Recent
Elev
atio
n (m
)
Sampling Year
Median Range Limit Changes
122 m
15 m
41 m
61 m
Pope 1950
Yonahlossee salamander
0
0.2
0.4
0.6
0.8
1
914
1036
1158
1280
1402
1524
1646
Spec
ies
Occ
upan
cy (ψ
)
Elevation (meters)
Occupancy Recent
Occupancy Historical
1000
1100
1200
1300
1400
1950s 1990s Recent
Elev
atio
n (m
)
Survey Years
68.6m 32 m
Range Midpoints
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900
1000
1100
1200
1300
1950s Recent 1990s Recent
Elev
atio
n (m
)
Sampling Year
Slimy salamander Median Range Limit Changes
91.5 m
61 m
41 m
61 m
Slimy salamander
0
0.2
0.4
0.6
0.8
1
914 1036
1158 1280
1402 1524
1646
Spec
ies
Occ
upan
cy (ψ
)
Elevation (meters)
Occupancy Recent Occupancy Historical
800 850 900 950
1000 1050 1100 1150 1200 1250 1300
1950s 1990s 2000s
Elev
atio
n (m
)
Survey Years
61 m 41 m
Range Midpoints Caruso & Lips 2013
-‐10
-‐5
0
5
10
15
20
25
30
1940 1950 1960 1970 1980 1990 2000 2010 2020
Mean Tempe
rature (ºC)
Year
Jan Mean July Mean Annual Mean
Regional Climate
r2 = 0.007; P = 0.461
r2 = 0.014; P = 0.741
r2 = 0.016; P = 0.983
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Summary • Lack of consistent elevation midpoint, upper
limits, and lower limit changes
• Plethodon welleri shifted downslope
• Plethodon yonahlossee expanded upslope
• Plethodon cylindraceus constricted its range limits
• Regional climate did not indicate changes
Impact of Powerline Right-of-Way Mowing on Four-toed Salamander
(Hemidactylium scutatum) Nesting and Larval Survival
Amphibian Declines & Habitat Loss
Davidson et al. 2002
Lithobates draytonii
14 million
Petranka et al. 1993
90% of IUCN listed Amphibians
Effects of canopy loss: • Barriers for juvenile dispersal • Desiccation and mortality • Reduced abundances
Semlitsch et al. 2009
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Habitat Loss & Right-of-Ways 2.8 million hectares of ROWs
Mechanical mowing
Negative impacts to other species of herpetofauna
~11,000 miles2
> 2,500
Gopherus polyplemus
Wetland Mitigation Sites
Salamanders?
New Regulations August 2003
Federal Energy Regulatory Commission (FERC) • Utility will face significant fines • Recommend clearing beyond minimum
September 2013
Objectives I. Impact on Nesting
II. Female Site Fidelity III. Impact on Larval Development IV. Time Needed for Recovery
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Study Area TVA
South Holston River Weir Dam (Sullivan Co., TN)
• Floodplain Forest • 3 Utility Transmission Line • ROWs mechanical mowed
every 5 years
August 2007 & 2012
Four-toed Salamander Hemidactylium scutatum
• “In Need of Management” • Species of Greatest Conservation Need – Tier 1
Pool Breeding Plethodontid
Shallow moss lined temporary pools
Larvae fall into pools after hatching
Females guard eggs
(Bruce 1988)
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• Number of eggs • Female SVL & TL • Noted female absence
Nesting Parameters & Site Fidelity Located nests March/April 2007 - 2012
Photographed female ventral surface
Harris & Ludwig 2004
Nesting Success 1-L buckets below nests caught hatchlings
Larval Success • Larval period • Survival rates • Size at metamorphosis
15 x 15 m
Current 5-year mowing cycle
Annual mowing cycle
Forest
Forest
15 x 15 m
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ROW Mowing
August 2008 1 summer of growth
August 2009 2 summers of growth
August 2011 4 summers of growth
August 2010 3 summers of growth
Mesocosm Pools FOREST EDGE ROW
Annual Mow
5-yr Mow
3m
3m
Mesocosm Pools
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Added • 10 larvae • 100 g leaf litter • 2 g rabbit chow • 1 l zooplankton
Pools searched weekly
Weight, SVL, & TL
Water temperatures
Mesocosm Pools
NPP = measured DO Earl & Semlitsch 2012
Results – Nesting Success
0
10
20
30
40
50
60
70
80
Forest ROW
Mean Pe
rcen
t Survival
Treatment
Present Absent
95% CI
P < 0.001
Harris et al. 1995
0
10
20
30
40
50
60
70
80
90
Prior Mowing 1 Year Post 2 Years Post 3 Years Post 4 Years Post
Percen
t Aba
ndon
ded Nests
Time Since Mowing
Forest
ROW
P < 0.01
P < 0.01
Results – Nesting Success
P < 0.001 3 of 5 years = sink
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0
10
20
30
40
50
60
70
80
90
Prior Mowing 1 Year Post 2 Years Post 3 Years Post 4 Years Post
Mean Pe
rcen
t Survival
Time Since Mowing
Forest ROW P < 0.03
Results – Nesting Success
3 of 5 years = sink SEM
3 April 2010 TL = 49.4 32 eggs
2 April 2011 TL = 81.8 38 eggs
1 April 2012 TL = 88.6 Laying eggs
Results – Nesting Site Fidelity
Yurewicz and Wilbur 2004
Tail loss impacts ova production ?
Forest 12.0 – 17.1%
ROW 0%
Female Sink?
Results – Larvae Reduced survival 9 m into ROW for 1 & 2 years
2/5 years sink
0 10 20 30 40 50 60 70 80 90
1 Year 2 Years 3 Years 4 Years Mean Pe
rcen
t Survival
Time Since Mowing
5-‐year
Annual
9 m into ROW
6 m for 1 year PM
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Results – Temperatures
Vegetation cooled pools 3 years PM
9 m & 6 m into ROW warmer
0
10
20
30
40
50
60
70
80
90
100
17 18 19 20 21 22 23 24 25 26
Perc
ent S
urvi
val
Mean Temperature (°C)
(rs = -0.207, P < 0.01)
Results – Larvae
Results – Metamorphs Smaller metamorphs (TL) 9 m into ROW from the AT
2-years 4 -years
P < 0.03 P < 0.02
Smaller size : Decreased survivorship and adult fitness
Wilbur-Collins Model 1973
Unfavorable conditions: • Smaller • Reduced time to metamorphosis
Semlitsch et al. 1988 Scott et al. 2007
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15
20
25
30
35
40
45
50
55
17 18 19 20 21 22 23 24 25 26
Mea
n D
ays
to
Met
amor
phos
is
Mean Temperature (°C)
Results – Larvae Quicker metamorphosis 6 & 9 m into ROW in both treatments
Other Plethodontids Beachy 1995
(rs = -0.589, P < 0.01)
Summary
• Impacts of ROW Mowing last for at least 3 years of the 5- year mowing cycle
• ROW nests are abandoned significantly more than forest nests for 3 years PM
• Females nesting in the ROW appear to not return for future nesting attempts • Embryonic survival is significantly less in ROW for 3 of 5 years
Summary • Larval survival was significantly reduced 9 & 6 m into the ROW, but improved 3 years PM
• Larvae metamorphosed significantly smaller 9 m into the ROW within the AT
• Larvae metamorphosed significantly quicker 9 & 6 m into the ROW • Time to metamorphosis was negatively related to temperatures
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Management Recommendation Integrated Vegetation Management (IVM)
Yahner et al. 2001
“The best and cheapest controls for vegetation are not chemicals but other plants” Rachel Carson, Silent Springs
5-year cycle
6-year cycle
Special Thanks: Funding
University of Tennessee Institute of Agriculture: • Hazelwood Scholarship
Virginia Community College System: • Paul Lee Professional Development Grant • Chancellor’s Faculty Fellowship • Tech Prep Program
Virginia Department of Game & Inland Fisheries: • State Wildlife Grant from U.S. Fish & Wildlife Service
Tennessee Wildlife Resource Agency: • State Wildlife Grant from U.S. Fish & Wildlife Service
Special Thanks: Logistics & Field Work
• Dr. & Mrs. James Organ • Aaron Horton • Brian Park • Joey McKenna • Gary Poe • Greg Schneider & Univ. of Michigan Museum of Zoology • Clive Devoy & Marianne Lagerklint - Univ. of Maine • Numerous Private Property Owners • Mt. Rogers National Recreation Area - USFS • VA Dept of Game & Inland Fisheries • Tennessee Valley Authority • Appalachian Well Drilling • City of Bristol TN
Logistics & Field Work:
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Questions
