FN Archimer Export Format
PT J
TI Monomethylmercury sources in a tropical artificial reservoir
BT 
AF MURESAN, B
   COSSA, Daniel
   RICHARD, Sophie
   DOMINIQUE, Y
AS 1:1;2:1;3:2;4:3;
FF 1:;2:;3:;4:;
C1 IFREMER, F-44311 Nantes 3, France.
   Lab Petit Saut, HYDRECO, F-97388 Kourou, French Guiana.
   CNRS, LEESA, F-33120 Arcachon, France.
C2 IFREMER, FRANCE
   HYDRECO, FRANCE
   CNRS, FRANCE
IN WOS Ifremer jusqu'en 2018
   copubli-france
IF 1.857
TC 27
TU CNRS
   EPHE
   IFREMER
   UNIVERSITE BORDEAUX
UR https://archimer.ifremer.fr/doc/2008/publication-4198.pdf
LA English
DT Article
CR AMANDES I
BO Unknown
DE ;Tropical environment;Artificial reservoir;Methylmercury;Mercury
AB The distribution and speciation of mercury (Hg) in the water column, the inputs (wet deposition and tributaries) and the outputs (atmospheric evasion and outlet) of an artificial partially anoxic tropical lake (Petit-Sa-Lit reservoir, French Guiana) were investigated oil a seasonal basis in order to appraise the cycling and transformations of this metal. The total mercury (HgT) concentrations in the oxygenated epilimnetic waters averaged 5 +/- 3 pmol L-1 in the unfiltered samples (HgTUNF) and 4 +/- 2 pmol L-1 in the dissolved (HgTD) phase (< 0.45 mu m). On average, the monomethylmercury (MMHg) constituted 8%, 40%, and 18% of the HgT in the dissolved phase, tile particulate suspended matter and in tile unfiltered samples, respectively. Covariant elevated concentrations of particulate MMHg and chlorophyll a in the epilimnion suggest that phytoplankton is ail active component for the MMHg transfer in tile lake. In the anoxic hypolimnion the HgTUNF averages 13 +/- 6 pmol L-1 and tile HgTD 8 +/- 4 pmol L-1. The averages of MMHgP and MMHgD in hypolimnetic waters were two and three times the corresponding values of the epilimnion, 170 +/- 90 pmol g(-1) and 0.9 +/- 0.5 pmol L-1, respectively. In the long dry and wet seasons, at the flooded forest and upstream dam sampling stations, the vertical profiles of MMHgD concentrations accounted for two distinct maxima: one just below the oxycline and the other near the benthic interface. Direct wet atmospheric deposition accounted for 14 moles yr(-1) HgTUNF, with 0.7 moles yr(-1) as MMHgUNF, while circa 76 moles yr(-1) of HgTUNF, with 4.7 moles yr(-1) as MMHgUNF, coming from tributaries. Circa 78 moles (similar to 17% as MMHg) are annually exported through tile dam, while 23 moles yr(-1) of Hg-0 evolve in the atmosphere. A mass balance calculation suggests that the endogenic production of MMHgUNF attained 8.1 moles yr(-1), corresponding to a methylation rate of 0.06% d(-1). As a result, tile Petit-Saut reservoir is a large man-made reactor that has extensively altered mercury speciation in favor of methylated species.
PY 2008
PD MAY
SO Applied Geochemistry
SN 0883-2927
PU Elsevier
VL 23
IS 5
UT 000256262200010
BP 1101
EP 1126
DI 10.1016/j.apgeochem.2007.11.006
ID 4198
ER

EF