Trophic Transfer Models for South River
Trophic Transfer Models for South River Mike Newman & Kyle Tom College of William & Mary – VIMS In Partnership with URS
Core Premise Once mercury enters the biota, its most important movements to understand are those involving trophic movement. Its movement can be modeled quantitatively.
Goals Can models effectively predict mercury biomagnification in South River? –One model for contaminated region or several? –Trend in model parameters with distance from past source? –Is the predictive capability of models sufficient? –Can % methylHg be quantified with trophic position
Sampling Sites - 2007
Constitution North
Park (0.6 mi)
Park (2.0 mi)
Dooms (5.2 mi) Pool (≈8.7 mi) Crimora
(AFC) (11.8 mi)
Grottoes (22.4 mi)
2007 URS/VIMS Sampling
Biomagnification Models a b
[ Hg ]i e e
15
Ni
a b1
or e e
N i b2 RM
15
Distance Biomagnification
Baseline
Biomagnification Models Physid
Blackfly
Helisoma
Total Mercury Model LTHG 3 2 1 0
R2=0.40 Slope=0.30±0.03 Intercept=-2.58±0.26
-1 -2 -3 5 0
1 6 2
7 3
48
5
96
710
8 119
12 11 1312 10
14 13
14 1515
16
D DE ELN LN15 15 O R A O RG G AN NII S SM M
B BG GS Sunf unf ii sh sh C hub Chub E er Ephem phem er el el ll ii dae dae LM B ass LM Bass RB unf i on sh P er iSphyt W er penny S tatenonem a hydr opsychi Z ygopt er a dae
B ii nnow BN NM M nnow C or bi cul Cor bi cul a a F al l F i sh Fal l Fi sh Lept oxi Lept oxi s s SM assi sh R BB Sunf W hi ter epenny Sucker W at
hydr opsychi dae
B Baet aet ii dae dae C r ayf Cr ayf ii sh sh G om phi dae G om phi dae Longnose Dace Longnose D ace SM t enonem S Bass a Zhi ygopt a W t e er Sucker
Methylmercury Models PrH edi HG LM G ct ed Val ue of LM 3 3
2
2
1 0 -R 12=0.78
1 0
-2 -3
Both significant -4 - 5at p Methylmercury > Fraction as methylmercury > Probably total mercury soon 2. Are important “outlier” biota to keep in mind. 3. More methylmercury enters food web with distance downriver. Reason for “Hump”? 4. Essentially all methylmercury at 20 consumer and higher. 5. Inorganic mercury is trophically diluted.
Core Premise Once mercury enters the biota, its most important movements to understand are those involving trophic movement. Its movement can be modeled quantitatively.
Goals Can models effectively predict mercury biomagnification in South River? –One model for contaminated region or several? –Trend in model parameters with distance from past source? –Is the predictive capability of models sufficient? –Can % methylHg be quantified with trophic position
Sampling Sites - 2007
Constitution North
Park (0.6 mi)
Park (2.0 mi)
Dooms (5.2 mi) Pool (≈8.7 mi) Crimora
(AFC) (11.8 mi)
Grottoes (22.4 mi)
2007 URS/VIMS Sampling
Biomagnification Models a b
[ Hg ]i e e
15
Ni
a b1
or e e
N i b2 RM
15
Distance Biomagnification
Baseline
Biomagnification Models Physid
Blackfly
Helisoma
Total Mercury Model LTHG 3 2 1 0
R2=0.40 Slope=0.30±0.03 Intercept=-2.58±0.26
-1 -2 -3 5 0
1 6 2
7 3
48
5
96
710
8 119
12 11 1312 10
14 13
14 1515
16
D DE ELN LN15 15 O R A O RG G AN NII S SM M
B BG GS Sunf unf ii sh sh C hub Chub E er Ephem phem er el el ll ii dae dae LM B ass LM Bass RB unf i on sh P er iSphyt W er penny S tatenonem a hydr opsychi Z ygopt er a dae
B ii nnow BN NM M nnow C or bi cul Cor bi cul a a F al l F i sh Fal l Fi sh Lept oxi Lept oxi s s SM assi sh R BB Sunf W hi ter epenny Sucker W at
hydr opsychi dae
B Baet aet ii dae dae C r ayf Cr ayf ii sh sh G om phi dae G om phi dae Longnose Dace Longnose D ace SM t enonem S Bass a Zhi ygopt a W t e er Sucker
Methylmercury Models PrH edi HG LM G ct ed Val ue of LM 3 3
2
2
1 0 -R 12=0.78
1 0
-2 -3
Both significant -4 - 5at p Methylmercury > Fraction as methylmercury > Probably total mercury soon 2. Are important “outlier” biota to keep in mind. 3. More methylmercury enters food web with distance downriver. Reason for “Hump”? 4. Essentially all methylmercury at 20 consumer and higher. 5. Inorganic mercury is trophically diluted.
