SUPPLEMENTAL DATA
The impacts of organic matter on the distribution and methylation of mercury in
hydroelectric reservoir in Wujiang River, Southwest China
BO MENG,† XINBIN FENG,*† GUANGLE QIU,† ZHONGGEN LI,† HENG YAO,† LIHAI
SHANG,† HAIYU YAN,†
†State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese
Academy of Sciences, Guiyang 550002, P.R. China
6 pages in total, detailed descriptions concerning Wujiangdu reservoir, Tables S1-S2, and Figure
S1.
1
Wujiangdu reservoir. The climate of Wujiangdu reservoir (WJD) represents a typical humid
subtropical monsoon with an average annual rainfall of 900-1400 mm and an annual mean
temperature of 14.6 °C. WJD was built in 1979, and has a watershed of 27,790 km2 and a total
volume of 2.3 × 109 m3; the surface area of WJD is 47.8 km2. Due to the Karstic environment of
the Wujiang River Basin, the bedrocks of the watershed of WJD mainly consist of limestone and
dolomite. WJD is a typical deep valley type reservoir. Its water depths increased from the
upstream to the downstream and reached the maximum at the dam. Concentrations of TN, TP,
chlorophyll, and phytoplankton cell density/ biomass in WJD increase from the upstream to the
downstream during our sampling periods (Dang, 2008). It was showed that the water at the
downstream of WJD is at a state of hyper-eutrophic, while the upper and middle reach of WJD is
oligotrophic-mesotrophic during our sampling periods (Dang, 2008; Kimmel and Groeger,
1984). Detailed information on basic characteristics of WJD can be obtained from other studies
(Meng et al., 2010; Feng et al., 2009a, b)
2
Table S1. Seasonal and spatial distribution of organic matter content, total mercury (THg),
methyl mercury (MeHg), and MeHg (%) in surface sediment of WJD.
Sampling site
Seasons
Organic matter
(%)
THg (ng g-1)
MeHg (ng g-1)
MeHg/THg (%)
Spring
5.3
240
3.0
1.3
Summer
3.7
280
3.0
1.1
Fall
4.2
273
2.4
0.87
Winter
4.5
228
1.3
0.56
Spring
5.4
209
5.9
2.8
Summer
4.8
170
4.5
2.7
Fall
4.3
229
3.8
1.6
Winter
5.5
241
4.3
1.8
Spring
11
282
8.3
2.9
Summer
11
273
6.1
2.2
Fall
8.8
282
2.7
1.0
Winter
11
401
7.6
1.9
Spring
9.9
307
5.1
1.7
Summer
11
350
5.3
1.5
Fall
8. 8
179
7.5
4.2
Winter
11
428
3.7
0.87
WS
WZ
WX
WD
3
Table S2. Seasonal and spatial distribution of dissolved inorganic mercury (IHgf), dissolved
methylmercury (MeHgf), and MeHgf (%) in surface sediment pore water and in interface water
of WJD.
Sampling site
Surface sediment pore water
Interface water
IHgf (ng L-1)
MeHgf (ng L-1)
IHgf (ng L-1)
MeHgf (ng L-1)
Spring
1.2
2.4
0.60
0.19
Summer
9.7
1.2
1.1
0.06
Fall
2.6
0.58
0.77
0.19
Winter
2.0
1.0
1.4
0.23
Spring
4.5
1.6
1.5
0.26
Summer
1.4
3.1
0.76
0.07
Fall
5.8
0.95
1.0
0.12
Winter
10
0.52
1.4
0.098
Spring
4.2
5.3
1.4
0.33
Summer
18
4.5
1.4
3.3
Fall
4.0
0.89
0.98
0.13
Winter
1.9
0.88
1.2
0.16
Spring
0.94
7.3
0.35
1.32
Summer
20
4.0
1.2
0.74
Fall
1.8
1.4
0.23
3.75
Winter
3.6
1.5
1.3
4.78
Seasons
WS
WZ
WX
WD
4
Figure S1. Linear regression fits between organic matter content and MeHg concentration in
8
6
y=0.41x+2.3
r =0.52, p<0.0001, n=80
WZ
8
Organic matter (%)
WS
Organic matter (%)
sediments of WJD.
6
4
2
0
4
2
0
0
2
WX 15
MeHg (ng g-1)
4
6
0
WD
y=1.1x+2.6
r =0.75, p<0.0001, n=80
9
6
3
0
0
2
4
6
MeHg (ng g-1)
2
15
8
10
4
MeHg (ng g-1)
6
8
y=1.0x+3.1
r =0.70, p<0.0001, n=80
12
Organic matter (%)
12
Organic matter (%)
y=0.55x+2.1
r =0.77, p<0.0001, n=80
9
6
3
0
0
2
5
4
6
MeHg (ng g-1)
8
10
Literature cited
1.
2.
3.
4.
5.
6.
Dang, A.Z., 2008. The impact of cascade exploitation on the phytoplankton in the upper reaches of
the Wujiang River. Master’s thesis. Guizhou Normal Univ., Guiyang, China (In Chinese, with
English abstract).
Meng, B., Feng, X.B., Chen, C.X., Qiu, G.L., Sommar, J., Guo, Y.N., Wan, Q., 2010. Influence of
Eutrophication on the Distribution of Total Mercury and Methylmercury in Hydroelectric Reservoirs.
J. Environ. Qual. 39, 1624-1635.
Feng, X.B., Jiang, H.M., Qiu, G.L., Yan, H.Y., Li, G.H., Li, Z.G., 2009a. Geochemical processes of
mercury in Wujiangdu and Dongfeng reservoirs, Guizhou, China. Environ. Pollut. 157, 2970-2984.
Feng, X.B., Jiang, H.M., Qiu, G.L., Yan, H.Y., Li, G.H., Li, Z.G., 2009b. Mercury mass balance
study in Wujiangdu and Dongfeng Reservoirs, Guizhou, China. Environ. Pollut. 157, 2594-2603.
Dang AZ. 2008. The impact of cascade exploitation on the phytoplankton in the upper reaches of the
Wujiang River. Master thesis. Guizhou Normal Univ., Guiyang, China.
Kimmel, B.L., Groege, A.W., 1984. Factors controlling primary production in lakes and reservoirs:
A perspective. Lake Reserv. Manage. 1, 277-281.
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