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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. McMahon
    Professor of Biology and Dean of the Honors College
                        John A. Morse
               Graduate Research Assistant
            The University of Texas at Arlington
                          Box 19222
                   Arlington, Texas 76019
                                                  UT Arlington
                    11 September 2007
           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
               Mortality after 28 days at 29°C in zebra
              mussels acclimated to 25° and 30°C (2006)
              100
              90
              80
              70
% Mortality




              60
              50
              40
              30
              20
              10
               0
                        25 °C                         30 °C
                          Acclimation Temperature
                                Oklahoma   New York
                      28-Day Chronic Thermal Test Results 2007
                        14    16     6.5   26 4.5   19 3   5.5 2   1 1.5   0.5 0.5
               100%

               90%

               80%

               70%
 % Mortality




               60%

               50%

               40%

               30%

               20%

               10%

                0%
                      27°C   28°C   29°C   30°C     31°C   32°C    33°C     34°C
                                              Test Temp
Numbers above bars represents the time (in
days) to achieve 100% mortality                                     NY     OK
                                Oologah Lake Water Temperature
                   35

                   30
Temperature (°C)




                   25

                   20

                   15

                   10

                   5

                   0
                        Jul   Aug     Sep   Oct   Nov   Dec   Jan   Feb   Mar     Apr   May Jun
                                    2006                                        2007
                                                        Month
                Mortality after 28 days at 29°C in Lake Oologah zebra
               mussels acclimated to 20°, 25° and 30°C in 2006 and 2007
              100.0%



              90.0%



              80.0%


              70.0%



              60.0%
% Mortality




              50.0%



              40.0%



              30.0%


              20.0%



              10.0%



               0.0%
                       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

                 20°C 2006                25°C 2006                      30°C 2006                         20°C 2007                      25°C 2007                     30°C 2007
Lake Mead Quagga Mussel Research
                         Size Distributions of Quagga Mussels in Lake Mead

                             5               2 0 0 6 Co h o r t   Las Vegas Boat Har bor , Lake M ead: 1/ 16/ 07
                             4
                             3
                             2
                             1                                                  2 0 0 5 Co h o r t
                             0
                             5                                         Cal l vi l l e M ay M ar i na, Lake M ead: 1/ 26/ 07
                             4                    2 0 0 6 Co h o r t
Frequency i n S ampl e (%)




                             3                                                            House Boat Pont oons
                             2
                             1
                             0
                             5                                          Lake M ead M ar i na, Lake M ead: 2/ 24/ 07
                             4
                             3                           2 0 0 6 Co h o r t    Cem ent Bl ocks and Cr oss Bar s
                             2                                                               Shal l ow        W at er ( 4 f t )
                             1                                                           2 0 0 5 Co h o r t
                             0
                             5                                 Kat
                                                2 0 0 6 Co h o r t er i   ne Landi ng, Lake M ohave: 3/ 13/ 0
                             4
                             3                                                              House Boat Hul l s
                             2
                             1                                                               2 0 0 5 Co h o r t
                             0
                             5                                         Cal l vi l l e Bay M ar i na, Lake M ead: 3/ 16/ 07
                             4                   2 0 0 6 Co h o r t
                             3                                                            House Boat Pont oons
                             2
                             1
                             0
                                 0   3   6           9        12         15     18        21         24         27      30
                                                           hel
                                                          S l Length (mm)
                         28 Day Mortality for Lake Mead Quagga
                            Mussels Exposed to 20°C – 33°C
                                                                   20d   5d   2d   1/2d   1/4
              100%                                                                         d
              90%
              80%
              70%
% Mortality




              60%
              50%
              40%
              30%
              20%
              10%
               0%
                     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

                         Numbers above bars represent the approximate number
                                   of days to reach 100% mortality.
                             Temperature (°C)




1m
                                                      35




                     0
                         5
                             10
                                  15
                                       20
                                                 30

                                            25
              1/1/2006

              2/1/2006




6m
             2/26/2006

             3/26/2006




12m
             4/23/2006

             5/21/2006




15m
             6/18/2006

             7/16/2006




      Date
20m
             8/13/2006

             9/10/2006

30m          10/8/2006

             11/5/2006
50m




             12/3/2006

              1/1/2007
                                                           Lake Mead Temperature Profile at Sentinel Island




80m




              2/1/2007
                     Isolated Water Bodies Sampled
                  ISOLATED WATERS                              NON-ISOLATED WATERS
          Water Body              State   Comments        Water Body         State   Comments
Oologah Lake (after Aug. 2006)     OK      Obtained    Mohawk River           NY      Obtained

Oologah Lake (before Aug. 2006)    OK      Obtained    Lake Michigan**        MI      Obtained

El Dorado                          KS      Obtained    Lake Erie**            OH      Obtained

White River                        AK     Collection   Lake Ontario*          NY      Obtained
                                           planned     St. Lawrence River*    NY     Collection
Ossawinnamakee Lake                MN      Possible                                   planned
                                          collection   Upper Mississippi             Collection
Saratoga Lake                      NY      Obtained                                   planned

Hedges Lake                        NY      Obtained    Lower Mississippi      LA     Collection
                                                                                      planned
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
                    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

				
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