Mercury in Mediterranean Mercury in Mediterranean waters waters

Milena Horvat, JoMilena Horvat, Jožže Kotnik, Vesna Fajon, Darija Gibie Kotnik, Vesna Fajon, Darija Gibiččar, Nives ar, Nives Ogrinc, David Kocman, Arne BratkiOgrinc, David Kocman, Arne Bratkičč

JoJožžef Stefan Institute, Department of Environmental Sciences, ef Stefan Institute, Department of Environmental Sciences, Jamova 39, SIJamova 39, SI--1000 Ljubljana, SLOVENIA1000 Ljubljana, SLOVENIA

Sampling and analysisSampling and analysis

•• MAMCS (1998MAMCS (1998--2000)2000)

•• MERCYMS 2002MERCYMS 2002--20042004((August 2003August 2003, , March/April 2004March/April 2004, , October/November 2004October/November 2004, , June/July 2005June/July 2005, June 2009, , June 2009, August 2010)August 2010)

•• MERIAN 2010MERIAN 2010

Sampling locations: Sampling locations: -- summer 2003 (13 locations)summer 2003 (13 locations)

-- spring 2004 (9 locations)spring 2004 (9 locations)

fallfall 20020044 (1(144 locations)locations)summersummer 20020055 ((1818 locations)locations)

summersummer 20102010 ((1919 locations) locations)

Cycling of Hg and its compounds in ocean watersCycling of Hg and its compounds in ocean waters

Analytical methodsAnalytical methods

ParameterParameter PrePre--treatmenttreatment DetectionDetection ReferenceReference

DGMDGM Purging, 0.5 l, 10 min, double Purging, 0.5 l, 10 min, double

amalgamationamalgamationCV AFSCV AFS Horvat et al. 2003Horvat et al. 2003

DMeHgDMeHg Purging, 2 l, 10 min, Purging, 2 l, 10 min, adsorption on Tenaxadsorption on Tenax, , thermal desorption, pyroliticthermal desorption, pyrolitic decompositiondecomposition

CV AFSCV AFS Bloom and Fitzgerald Bloom and Fitzgerald

19881988

RHgRHg SnClSnCl22 reduction, amalgamationreduction, amalgamation CV AASCV AAS Horvat et al. 1988, Horvat et al. 1988,

19911991

THg NFTHg NF HCl acidification, BrCl oxidation, UV HCl acidification, BrCl oxidation, UV

irradiation, SnClirradiation, SnCl22 reduction, areduction, ammalgamationalgamationCV AASCV AAS Horvat et al. 1987, Horvat et al. 1987,

19911991

THg FTHg F Filtration 0.45 Filtration 0.45 µµmm, HCl acidification, BrCl , HCl acidification, BrCl

oxidation, UV irradiation, SnCloxidation, UV irradiation, SnCl22 reduction, reduction,

aammalgamationalgamation

CV AASCV AAS Horvat et al. 1987, Horvat et al. 1987,

19911991

MeHg NFMeHg NF Solvent extraction, thermal desorption, Solvent extraction, thermal desorption,

pyrolitic decompositionpyrolitic decompositionCV AFSCV AFS Horvat et al. 1993, Horvat et al. 1993,

Liang et al. 1994, Liang et al. 1994,

19961996

MeHg FMeHg F Filtration 0.45 Filtration 0.45 µµmm, solvent extraction, , solvent extraction,

thermal desorption, pyrolitic decompositionthermal desorption, pyrolitic decompositionCV AFSCV AFS Horvat et al. 1993, Horvat et al. 1993,

Liang et al. 1994, Liang et al. 1994,

19961996

Spatial distribution of DGM Spatial distribution of DGM –– summer 2003summer 2003

Surface

Bottom

Spatial distribution of DGM Spatial distribution of DGM –– spring 2004spring 2004

Surface

Bottom

Bathymetry and DGM in selected profiles

Spatial distribution of DGM Spatial distribution of DGM –– summer 2005summer 2005

Surface Bottom

Spatial distribution of dissolved Spatial distribution of dissolved THg and MeHgTHg and MeHg

Surface Bottom

Comparison of the results – surface waters

Study areaStudy area Total HgTotal Hg

ng/lng/l

RHg RHg

ng/lng/l

MeHgMeHg

pg/lpg/l

DGMDGM

pg/lpg/l

Summer 2000 Summer 2000

Summer 2003Summer 2003

Spring 2004Spring 2004

Fall 2004 (Adriatic)Fall 2004 (Adriatic)

Fall 2004 (Mediterranean)Fall 2004 (Mediterranean)

Summer 2005 (Adriatic)Summer 2005 (Adriatic)

Summer 2005 (Mediterranean)Summer 2005 (Mediterranean)

0.29 0.29 ±± 0.080.08

0.20 0.20 ±± 0.120.12

0.18 0.18 ±± 0.070.07

0.67 0.67 ±± 0.360.36

0.550.55

0.16 0.16 ±± 0.060.06

0.05 0.05 ±± 0.060.06

0.06 0.06 ±± 0.050.05

0.12 0.12 ±± 0.100.10

0.05 0.05 ±± 0.020.02

0.11 0.11 ±± 0.100.10

3535

56.2 10.156.2 10.1

63 63 ±± 3636

89 89 ±± 4949

103 103 ±± 2323

87 87 ±± 3434

8181

30.1 30.1 ±± 24.124.1

34 34 ±± 2121

65 65 ±± 4040

45 45 ±± 4040

35 35 ±± 1717

64 64 ±± 3535

3636

W Mediterranean W Mediterranean

(Cossa (Cossa et al.et al. 1997)1997)

(Heimburger (Heimburger et al.et al. 2010)2010)

0.51 0.51 ±± 0.250.25 0.080.08 < 30.1< 30.1

3030

< LOD < LOD –– 78.278.2

N Atlantic N Atlantic

(Mason (Mason et al.et al. 1998) 1998) 0.48 0.48 ±± 0.320.32 0.16 0.16 ±± 0.030.03 209 209 ±± 217217 96.3 96.3 ±± 62.262.2

Equatorial PacificEquatorial Pacific

(Mason and Fitzgerald 1993)(Mason and Fitzgerald 1993) n.d.n.d. 0.09 0.09 –– 0.370.37 < LOD < LOD –– 56.256.2 8.02 8.02 –– 65.265.2

S and Equatorial PacificS and Equatorial Pacific

(Mason and Sullivan 1999)(Mason and Sullivan 1999) 0.58 0.58 ±± 0.240.24 0.34 0.34 -- 0.240.24 n.d.n.d. n.d.n.d.

% of Hg in different forms - August, 2003

Hg speciesHg species Eastern legEastern leg Western legWestern leg

% MeHg % MeHg 3939 1010

% DGM% DGM 2626 2727

% Reactive% Reactive 2424 1919

% T% T--Hg dissHg diss 5656 7711

DMHg 1.25 DMHg 1.25 –– 9.67 in W leg9.67 in W leg< LOD in E leg< LOD in E leg

MeHgdiss:78%

Vertical distribution of Vertical distribution of different Hg species different Hg species

Vertical distribution of different Hg Vertical distribution of different Hg speciesspecies –– summer 2003 summer 2003 -- spring 2004spring 2004

ST6

0.08 0.12 0.16 0.2 0.24DGM (pM)

1000

100

10

1

Dep

th (

m)

0 5 10 15 20 25Reactive Hg (pM)

1 1.2 1.4 1.6 1.8 2Total Hg (pM)

0.16 0.2 0.24 0.28 0.32 0.36

MeHg (pM)

DGMRHgTHgMeHg

13.2 13.6 14 14.4 14.8 15.2 15.6Temperature (0C)

1000

100

10

1

38.65 38.7 38.75 38.8 38.85 38.9 38.95Salinity (PSU)

200 210 220 230 240 250Oxygen (µM)

0 0.5 1 1.5 2 2.5Chlorophyll a (mg l-1)

Temp.Sal.Ox.Chl.

WP7

0 0.1 0.2 0.3DGM (pM)

1000

100

10

1

Dep

th (

m)

0.08 0.12 0.16 0.2 0.24 0.28Reactive Hg (pM)

0.4 0.8 1.2 1.6 2Total Hg (pM)

0.08 0.12 0.16 0.2 0.24 0.28

MeHg (pM)

DGMRHgTHgMeHg

12 16 20 24 28Temperature (0C)

1000

100

10

1

38.6 38.7 38.8 38.9 39Salinity (PSU)

140 160 180 200 220 240Oxygen (µM)

0 0.02 0.04 0.06 0.08Chlorophyll a (mg l-1)

Temp.Sal.Ox.Chl.

Vertical distribution of different Hg Vertical distribution of different Hg speciesspecies

0 0.02 0.04 0.06 0.08 0.1DGM, MeHg (ng l-1)

1000

100

10

1

200

300

400

500

600

700800900

20

30

40

50

60

708090

2

3

4

5

6

789

Dep

th (m

)

0 0.02 0.04 0.06 0.08 0.1RHg, THg (ng l-1)

ST 7

RHgTHg NFTHg FDGMMeHg FMeHg P

13.6 13.8 14 14.2 14.4 14.6 14.8Temperature (oC)

1000

100

10

1

200

300

400

500

600

700800900

20

30

40

50

60

708090

2

3

4

5

6

789

Dep

th (m

)

37.8 38 38.2 38.4 38.6 38.8 39Salinity (PSU)

8 8.04 8.08 8.12 8.16Oxygen (ml l-1)

0 1 2 3 4Chlorophyll a (mg m-3)

ST 7

Vertical distribution of Vertical distribution of different Hg speciesdifferent Hg species

WP4

0 0.1 0.2 0.3 0.4DGM (pM)

1000

100

10

1

Dep

th (

m)

0.05 0.1 0.15 0.2 0.25 0.3Reactive Hg (pM)

0.64 0.68 0.72 0.76 0.8 0.84Total Hg (pM)

0 0.1 0.2 0.3 0.4

MeHg (pM)

DGMRHgTHgMeHg

12 16 20 24 28 32Temperature (0C)

1000

100

10

1

37.2 37.6 38 38.4 38.8 39.2Salinity (PSU)

80 120 160 200 240 280 320Oxygen (µM)

0 5 10 15 20 25Chlorophyll a (mg l-1)

Temp.Sal.Ox.Chl.

ST5

0.1 0.2 0.3 0.4DGM (pM)

1000

100

10

1

Dep

th (

m)

0 0.2 0.4 0.6Reactive Hg (pM)

1 1.2 1.4 1.6 1.8 2Total Hg (pM)

0.1 0.2 0.3 0.4 0.5 0.6 0.7

MeHg (pM)

DGMRHgTHgMeHg

13.5 14 14.5 15 15.5 16Temperature (0C)

1000

100

10

1

38.2 38.4 38.6 38.8 39Salinity (PSU)

180 200 220 240 260Oxygen (µM)

0 5 10 15 20 25Chlorophyll a (mg l-1)

Temp.Sal.Ox.Chl.

Obtain supportive informations and data Obtain supportive informations and data from other groups to describe the from other groups to describe the observed variations of THg observed variations of THg