@article{fdi:010068930,
  title = {{T}he open sea as the main source of methylmercury in the water column of the {G}ulf of {L}ions ({N}orthwestern {M}editerranean margin)},
  author = {{C}ossa, {D}. and de {M}adron, {X}. {D}. and {S}chafer, {J}. and {L}anceleur, {L}. and {G}u{\'e}dron, {S}t{\'e}phane and {B}uscail, {R}. and {T}homas, {B}. and {C}astelle, {S}. and {N}audin, {J}. {J}.},
  editor = {},
  language = {{ENG}},
  abstract = {{D}espite the ecologic and economical importance of coastal areas, the neurotoxic bioaccumulable monomethylmercury ({MMH}g) fluxes within the ocean margins and exchanges with the open sea remain unassessed. {T}he aim of this paper is to address the questions of the abundance, distribution, production and exchanges of methylated mercury species ({M}e{H}g{T}), including {MMH}g and dimethylmercury ({DMH}g), in the waters, atmosphere and sediments of the {N}orthwestern {M}editerranean margin including the {R}hone {R}iver delta, the continental shelf and its slope ({G}ulf of {L}ions) and the adjacent open sea ({N}orth {G}yre). {C}oncentrations of {M}e{H}g{T} ranged from <0.02 to 0.48 pmol {L}-1 with highest values associated with the oxygen-deficient zone of the open sea. {T}he methylated mercury to total mercury proportion ({M}e{H}g{T}/{H}g{T}) increased from 2% to 4% in the {R}hone {R}iver to up to 30% (averaging 18%) in the {N}orth {G}yre waters, whereas, within the shelf waters, {M}e{H}g{T}/{H}g{T} proportions were the lowest (1-3%). {W}e calculate that the open sea is the major source of {M}e{H}g{T} for the shelf waters, with an annual flux estimated at 0.68 +/- 0.12 kmol a(-1) (i.e., equivalent to 12% of the {H}g{T} flux). {T}his {M}e{H}g{T} influx is more than 80 times the direct atmospheric deposition or the in situ net production, more than 40 times the estimated "maximum potential" annual efflux from shelf sediment, and more than 7 times that of the continental sources. {I}n the open sea, ratios of {MMH}g/{DMH}g in waters were always <1 and minimum in the oxygen deficient zones of the water column, where {M}e{H}g concentrations are maximum. {T}his observation supports the idea that {MMH}g could be a degradation product of {DMH}g produced from inorganic divalent {H}g.},
  keywords = {{M}ercury ; {M}ethylmercury ; {O}cean margin ; {C}oastal area ; {M}editerranean ; {MEDITERRANNEE} ; {GOLFE} {DU} {LION}},
  booktitle = {},
  journal = {{G}eochimica et {C}osmochimica {A}cta},
  volume = {199},
  numero = {},
  pages = {222--237},
  ISSN = {0016-7037},
  year = {2017},
  DOI = {10.1016/j.gca.2016.11.037},
  URL = {https://www.documentation.ird.fr/hor/fdi:010068930},
}