FN Archimer Export Format
PT J
TI Heavy metals distribution in mangrove sediments along the mobile coastline of French Guiana
BT 
AF MARCHAND, Cyril
   LALLIER VERGES, E
   BALTZER, F
   ALBERIC, P
   COSSA, Daniel
   BAILLIF, P
AS 1:1;2:1;3:2;4:1;5:3;6:1;
FF 1:;2:;3:;4:;5:PDG-DOP-DCN-BE-LBCM;6:;
C1 Univ Orleans, CNRS, Inst Sci Terre Orleans, UMR 6113, F-45067 Orleans, France.
   Univ Paris 11, CNRS, Dept Sci Terre, FRE 2566, F-91405 Orsay, France.
   IFREMER, Nantes 03, France.
C2 UNIV ORLEANS, FRANCE
   UNIV PARIS 11, FRANCE
   IFREMER, FRANCE
SI NANTES
SE PDG-DOP-DCN-BE-LBCM
IN WOS Ifremer jusqu'en 2018
   copubli-france
   copubli-univ-france
IF 2.663
TC 199
UR https://archimer.ifremer.fr/doc/2006/publication-1041.pdf
LA English
DT Article
DE ;French Guiana;Mangrove;Fe/Mn cycling;Heavy metals
AB The accumulation of nine heavy metals in fine-grained sediments from the mangrove fringed coast of French Guiana is evaluated. The dynamic features of the South American tropical coastline, from the Amazon to the Orinoco Rivers, result in mangrove sediments being alternately submitted to phases of erosion and net sedimentation a few tens of years long. This process influences the distribution of the heavy metals associated with these frequently re-mobilized deposits. Sedimentary cores and mangrove plant samples were collected, at different seasons, in various swamps characterized by different properties (content of sedimentary organic matter, distance from sea water and fresh water). The ranges of measured concentrations expressed in mu mol g(-1) were the following: Cu (0.06 to 0.61), Co (0.12 to 0.68), Pb (0.08 to 0.18), Ni (0.32 to 0.76), Cr (0.61 to 1.40), Zn (1.25 to 5.94), Mn (4.36 to 45.4) and Fe (441 to 1128). No differences were found between sediments from mangroves developing upstream and downstream of urban areas, i.e. Cayenne and Kourou. This suggests that the content of mangrove sediments in heavy metals along the coastline of French Guiana is essentially the result of the continuous alternation of accumulation and transport phases occurring upstream after departing from the Amazon watershed. The sources of this heavy metals content are thus difficult to identify. However it is well known that the alluvium produced by the natural erosion of the Amazonian soils is naturally enriched in mercury. Also, the run-off from gold mining activities is known to contribute to mercury pollution. Ranges in total Hg were between 0.15 and 2.57 nmol g(-1), with mean values close to 0.41 nmol g(-1), and were clearly correlated with total organic carbon except for some outstanding high values, which may be a result of rapid geochemical changes. Heavy metal concentrations showed variations with depth. The redox conditions and the decay processes affecting the organic matter control the cycling of iron and manganese, which in turn control the concentrations and associations of heavy metals. These preliminary results suggest that the variations in heavy metal content with depth or between mangrove areas result largely from diagenetic processes rather than changes in metal input resulting from local human activities. (c) 2005 Elsevier B.V. All rights reserved.
PY 2006
SO Marine Chemistry
SN 0304-4203
PU Elsevier
VL 98
IS 1
UT 000234914300001
BP 1
EP 17
DI 10.1016/j.marchem.2005.06.001
ID 1041
ER

EF