report on usfws contracted wrp research project assessment of the potential for zebra mussel...
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Report on USFWS Contracted WRP Research Project
Assessment of the Potential for Zebra Mussel Invasion of Waters in the Western United States
via Saltatory Dispersal and Evolution of Increased Thermal Tolerance
Dr. Robert F. McMahonProfessor of Biology and Dean of the Honors College
John A. MorseGraduate Research Assistant
The University of Texas at ArlingtonBox 19222
Arlington, Texas 76019
11 September 2007 UT Arlington
Research Objectives
● Compare the acute and chronic upper thermal limits of zebra mussel populations from a warm southwestern habitat and cooler northeastern habitat
● Use data to assess development of physiologically resistant (thermally tolerant) races of zebra mussels in isolated southwestern populations
● Comparing genetic fingerprints (Amplified Fragment Length Polymorphisms or AFLP) of isolated zebra mussel populations and comparing them with samples from potential source populations
● Use data to examine how mussel dispersal patterns from one drainage system to another
Results
Chronic Thermal Tolerance
●Mussel samples collected from Lake Oologah, Oklahoma (2206, 2007), and Saratoga Lake (2006) and Hedges Lake (2007) in New York
●Acclimated in the laboratory for over two weeks to 5°, 10°, 15°, 20°, 25° and 30°C
●Subsamples held concurrently for up to 28 days at temperatures of 28°C, 29°, 30°, 31°, 32°, 33° and 34°C
● Samples checked daily for mortality ● Dead individuals removed
0
10
20
30
40
50
60
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80
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100
25 °C 30 °CAcclimation Temperature
% M
ort
alit
y
Oklahoma New York
Mortality after 28 days at 29°C in zebra mussels acclimated to 25° and 30°C (2006)
28-Day Chronic Thermal Test Results 2007
Numbers above bars represents the time (in days) to achieve 100% mortality
14 16 6.5 26 4.5 19 3 5.5 2 1 1.5 0.5 0.5
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
27°C 28°C 29°C 30°C 31°C 32°C 33°C 34°CTest Temp
% M
ort
alit
y
NY OK
Tem
per
atu
re (
°C)
0
5
10
15
20
25
30
35
Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun
Month
Oologah Lake Water Temperature
2006 2007
0.0%
10.0%
20.0%
30.0%
40.0%
50.0%
60.0%
70.0%
80.0%
90.0%
100.0%
0 24
48
72
96
120
144
168
192
216
240
264
288
312
336
360
384
408
432
456
480
504
528
552
576
600
624
648
672
Hours
% M
ort
ali
ty
20°C 2006 25°C 2006 30°C 2006 20°C 2007 25°C 2007 30°C 2007
Mortality after 28 days at 29°C in Lake Oologah zebra mussels acclimated to 20°, 25° and 30°C in 2006 and 2007
Lake Mead Quagga Mussel Research
012345
Shell Length (mm)
012345
Fre
qu
en
cy
in S
am
ple
(%
)
012345
012345
0 3 6 9 12 15 18 21 24 27 30012345
Las Vegas Boat Harbor, Lake Mead: 1/16/07
Callville May Marina, Lake Mead: 1/26/07
House Boat Pontoons
Lake Mead Marina, Lake Mead: 2/24/07
Cement Blocks and Cross Bars
Shallow Water (4 ft)
Katerine Landing, Lake Mohave: 3/13/0
House Boat Hulls
Callville Bay Marina, Lake Mead: 3/16/07
House Boat Pontoons
2006 Cohort
2006 Cohort
2006 Cohort
2006 Cohort
2006 Cohort
2005 Cohort
2005 Cohort
2005 Cohort
Size Distributions of Quagga Mussels in Lake Mead
28 Day Mortality for Lake Mead Quagga Mussels Exposed to 20°C – 33°C
Numbers above bars represent the approximate number of days to reach 100% mortality.
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
% M
ort
ali
ty
20d 5d 2d 1/2d 1/4d
20°C 21°C 22°C 23°C 24°C 25°C 26°C 27°C 28°C 29°C 30°C 31°C 32°C 33°C
Temperature (°C)Starved Fed
35
Lake Mead Temperature Profile at Sentinel Island
0
5
10
15
20
25
30
Te
mp
era
ture
(°C
)
1/1/
2006
2/1/
2006
2/26
/200
6
3/26
/200
6
4/23
/200
6
5/21
/200
6
6/18
/200
6
7/16
/200
6
8/13
/200
6
9/10
/200
6
10/8
/200
6
11/5
/200
6
12/3
/200
6
1/1/
2007
2/1/
2007
Date1m 6m 12m 15m 20m 30m 50m 80m
Isolated Water Bodies SampledISOLATED WATERS
Water Body State Comments
Oologah Lake (after Aug. 2006) OK Obtained
Oologah Lake (before Aug. 2006) OK Obtained
El Dorado KS Obtained
White River AK Collection planned
Ossawinnamakee Lake MN Possible collection
Saratoga Lake NY Obtained
Hedges Lake NY Obtained
Ballston Lake NY Obtained
Base Lake NE Collection planned
Lake of the Ozarks MO Obtained
Diamond Lake MI Obtained
Detroit River MI Obtained
Wolf Lake IL Obtained
Mosquito Creek Reservoir OH Obtained
Milbrook Quarry VA Obtained
Lake Mead* NV Obtained
NON-ISOLATED WATERS
Water Body State Comments
Mohawk River NY Obtained
Lake Michigan** MI Obtained
Lake Erie** OH Obtained
Lake Ontario* NY Obtained
St. Lawrence River* NY Collection planned
Upper Mississippi Collection planned
Lower Mississippi LA Collection planned
Preliminary Conclusions
● Zebra mussels from Lake Oologah, Oklahoma are not more thermally tolerant than those from Saratoga or Hedges Lake in New York
● No evidence for selection of elevated thermal limits
● The incipient (long-term) upper thermal limit of zebra mussels Lake Mead qugga mussels appears to be ≈ 28°C regardless of latitude in North America
● The Lake Oologah, Oklahoma, zebra mussel population experienced near 100% extirpation during August 2006 and 2007 when water temperature rose above 28°C
● No evidence of selection for elevated thermal limits
● Lakes exceeding a surface temperature of 28°C for extended periods in the summer are unlikely to harbor zebra or quagga mussels
● Quagga mussels were first introduced to Lake Mead in 2003 or 2004
● Temperature profiles can be use to estimate the susceptibility of southwestern water bodies to zebra mussel invasion
● Lake Mead and the Lower Colorado River Lakes are susceptible to quagga and zebra mussel invasion
● Molecular analysis of the origins of isolated zebra mussel introductions will be completed by December 2006