Environmental Engineering Reference
In-Depth Information
The open ocean serves as a large source
and
sink for
atmospheric mercury (Figure 10.4). Inorganic Hg(II) in
the ocean can be reduced to elemental mercury, Hg(0), via
photochemical reactions and biologically mediated path-
ways (Lalonde et al., 2004; Mason et al., 2001; Rolfhus and
Fitzgerald, 2004; Monperrus et al., 2007; Poulain et al.,
2007; Whalin et al., 2007). Most marine surface waters
are supersaturated with volatile Hg(0), resulting in its eva-
sion to the atmosphere. Concentrations of DGM in surface
waters (which is primarily Hg(0)) and fl uxes of DGM to the
atmosphere for various coastal and open ocean environ-
ments are summarized in Table 10.2. The net fl ux of Hg(0)
table 10.2
Concentrations and Fluxes of Dissolved Gaseous Mercury, Primarily Hg(0), Measured
for Various Surface Waters in the Marine Environment
Surface water DGM
a
(fM)
DGM fl ux to atmosphere
a
(nmol m
2
d
1
)
Location
References
Arctic Ocean
220
110 (25-670)
b
0.29 (
0.19-11.8)
Andersson et al., 2008
Subtropical North
Pacifi c
60
30
0.10
0.09
Laurier et al., 2003b
Tropical North
Pacifi c
130
70
0.30
0.25
Laurier et al., 2003b
Equatorial Pacifi c
160
110 (40-360)
c
0.16-1.44
Mason and Fitzgerald, 1993
Subtropical North
Atlantic
650
390
d
1.9
1.3
Mason et al., 1998
Tropical North
Atlantic (Bermuda
Atlantic Time-
Series)
80-30
c
0.20-0.66
Mason et al., 2001
South, equatorial
Atlantic
790
(200 -4100)
e
1200
9.6
Lamborg et al., 1999; Mason and
Sullivan, 1999
Mediterranean
Sea
160
110 (20-520)
e
0.27 (0.22-0.60)
Gårdfeldt et al., 2003b; Horvat et al.,
2003; Kotnik et al., 2007; Rajar et al.,
2007; Žagar et al., 2007
San Francisco Bay
900
880 (10-2700)
b
0.3-5.5
Conaway et al., 2003; Macleod et al.,
2005
Long Island
Sound
200
130 (40-550)
b
0.32 (0.01-0.53)
Rolfhus and Fitzgerald, 2001
Chesapeake Bay
100-250
b
0.13 (0.05-0.20)
Mason et al., 1999
360 (100-650)
b
Scheldt Estuary
0.42
0.17 (0.23-0.70)
Baeyens and Leermakers, 1998;
Baeyens et al., 1998
North Sea
60-800
b
0.47
0.35 (0.06-1.11)
Baeyens and Leermakers, 1998
Atlantic Ocean,
Irish coast
110
40 (70-200)
b
0.33
0.22 (0.05-0.72)
Gårdfeldt et al., 2003b
Seine River
estuary
140 - 450
b
0.07-0.14
Coquery et al., 1997
Loire River
estuary
60-120
b
0.02-0.09
Coquery et al., 1997
note: Values reported as the mean
standard deviation, with range given in parentheses when also available.
a. Primarily as Hg
0
.
b.
2 m.
c.
50 m.
d.
100 m.
e.
20 m.
