Corbicula Clam Results 2003
Corbicula Clam Results 2003 Thomas R. Benzing James Madison University February 10, 2004
Ecology of Corbicula fluminea • non-native freshwater clam • first reported in Virginia in 1972 • average life span: 1-3 years • abundant in South River • filter rate: 8 – 800 mL per hour • typical adult size: 0.2 – 0.5 grams
Asiatic clam, C. fluminea
South River watershed boundary
South River Clam sampling locations (2001-2003)
Sampling Notes: November 15, 2003 Streamflow was higher than normal Evidence of recent scouring of river channel Clams were not as easy to find as last year Purged in deionized water for over 48 hours Shucked and frozen on November 18 Shipped to analytical lab on November 19
South River Stage during Hurricane Isabel (September 2003) 15.0
G a g e h e ig h t a t H a r r is to n (fe e t)
14.41 feet!
12.0
9.0
6.0
3.0
0.0 09/15/03
09/16/03
09/17/03
09/18/03
09/19/03
Date
09/20/03
09/21/03
09/22/03
09/23/03
South River Stage during November 2003
G a g e h e ig h t a t H a r r is to n (fe e t)
6.0
5.0
11/8/2003 9:00 AM 4.62 feet 11/15/2003 12:00 noon 3.86 feet
4.0
3.0
2.0
1.0
0.0 11/5/03
11/7/03
11/9/03
11/11/03
11/13/03
Date
11/15/03
11/17/03
11/19/03
Clam Tissue Results, 2003 Site ID
Description of Location
Replicates
Hg MeHg (ppm) (ppm)
CS01
Ridgeview Park (control)
2
0.040
CS03
Constitution Park
3
0.090
CS08
North Park
1
0.158
CS12
downstream of Hopeman Parkway bridge
3
0.115
0.048
CS18
Dooms
1
0.276
0.135
CS101
Augusta Forestry Center
3
0.286
0.111
CS401
Port Republic @ Town Park
3
0.322
0.026
Clam Tissue Results, 2003 0.40
Total Hg Methyl Hg Hg Concentration (ppmwet weight)
0.30
Methyl Hg = 38% Total Hg 0.20
0.10
0.00 CS01
CS03
CS12
CS18
Sampling Site ID
CS101
CS401
Sampling Location ID C S 18 C S 10 1 C S 40 1
C S 17
C S 16
C S 15
C S 14
C S 13
C S 12
C S 11
0.45
C S 10
C S 09
C S 08
C S 07
C S 06
C S 05
C S 04
C S 03
C S 02
C S 01
Hg Concentration (ppmwet weight)
Comparison of Clam Data, 2001-2003
0.60
2003 2002 2001
0.30
0.15
0.00
Ecology of Corbicula fluminea • non-native freshwater clam • first reported in Virginia in 1972 • average life span: 1-3 years • abundant in South River • filter rate: 8 – 800 mL per hour • typical adult size: 0.2 – 0.5 grams
Asiatic clam, C. fluminea
South River watershed boundary
South River Clam sampling locations (2001-2003)
Sampling Notes: November 15, 2003 Streamflow was higher than normal Evidence of recent scouring of river channel Clams were not as easy to find as last year Purged in deionized water for over 48 hours Shucked and frozen on November 18 Shipped to analytical lab on November 19
South River Stage during Hurricane Isabel (September 2003) 15.0
G a g e h e ig h t a t H a r r is to n (fe e t)
14.41 feet!
12.0
9.0
6.0
3.0
0.0 09/15/03
09/16/03
09/17/03
09/18/03
09/19/03
Date
09/20/03
09/21/03
09/22/03
09/23/03
South River Stage during November 2003
G a g e h e ig h t a t H a r r is to n (fe e t)
6.0
5.0
11/8/2003 9:00 AM 4.62 feet 11/15/2003 12:00 noon 3.86 feet
4.0
3.0
2.0
1.0
0.0 11/5/03
11/7/03
11/9/03
11/11/03
11/13/03
Date
11/15/03
11/17/03
11/19/03
Clam Tissue Results, 2003 Site ID
Description of Location
Replicates
Hg MeHg (ppm) (ppm)
CS01
Ridgeview Park (control)
2
0.040
CS03
Constitution Park
3
0.090
CS08
North Park
1
0.158
CS12
downstream of Hopeman Parkway bridge
3
0.115
0.048
CS18
Dooms
1
0.276
0.135
CS101
Augusta Forestry Center
3
0.286
0.111
CS401
Port Republic @ Town Park
3
0.322
0.026
Clam Tissue Results, 2003 0.40
Total Hg Methyl Hg Hg Concentration (ppmwet weight)
0.30
Methyl Hg = 38% Total Hg 0.20
0.10
0.00 CS01
CS03
CS12
CS18
Sampling Site ID
CS101
CS401
Sampling Location ID C S 18 C S 10 1 C S 40 1
C S 17
C S 16
C S 15
C S 14
C S 13
C S 12
C S 11
0.45
C S 10
C S 09
C S 08
C S 07
C S 06
C S 05
C S 04
C S 03
C S 02
C S 01
Hg Concentration (ppmwet weight)
Comparison of Clam Data, 2001-2003
0.60
2003 2002 2001
0.30
0.15
0.00
