Mercury in the Black Sea: New Insights From Measurements and Numerical Modeling - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Global Biogeochemical Cycles Année : 2018

Mercury in the Black Sea: New Insights From Measurements and Numerical Modeling

Résumé

Redox conditions and organic matter control marine methylmercury (MeHg) production. The Black Sea is the world's largest and deepest anoxic basin and is thus ideal to study Hg species along the extended redox gradient. Here we present new dissolved Hg and MeHg data from the 2013 GEOTRACES MEDBlack cruise (GN04_leg2) that we integrated into a numerical 1-D model, to track the fate and dynamics of Hg and MeHg. Contrary to a previous study, our new data show highest MeHg concentrations in the permanently anoxic waters. Observed MeHg/Hg percentage (range 9-57%) in the anoxic waters is comparable to other subsurface maxima in oxic open-ocean waters. With the modeling we tested for various Hg methylation and demethylation scenarios along the redox gradient. The results show that Hg methylation must occur in the anoxic waters. The model was then used to simulate the time evolution (1850-2050) of Hg species in the Black Sea. Our findings quantify (1) inputs and outputs of Hg T (~31 and ~28 kmol yr À1) and MeHg T (~5 and ~4 kmol yr À1) to the basin, (2) the extent of net demethylation occurring in oxic (~1 kmol yr À1) and suboxic water (~6 kmol yr À1), (3) and the net Hg methylation in the anoxic waters of the Black Sea (~11 kmol yr À1). The model was also used to estimate the amount of anthropogenic Hg (85-93%) in the Black Sea.
Fichier principal
Vignette du fichier
Rosati-2018-Mercury in the Black Sea_ New Insi.pdf (1.7 Mo) Télécharger le fichier
Origine : Fichiers éditeurs autorisés sur une archive ouverte
Loading...

Dates et versions

hal-01771698 , version 1 (04-10-2018)

Identifiants

Citer

G. Rosati, Lars-Eric Heimbürger-Boavida, D. Melaku Canu, C. Lagane, L. Laffont, et al.. Mercury in the Black Sea: New Insights From Measurements and Numerical Modeling. Global Biogeochemical Cycles, 2018, 32 (4), pp.529 - 550. ⟨10.1002/2017gb005700⟩. ⟨hal-01771698⟩
216 Consultations
107 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More