『Abstract
The Marais Vernier is the largest freshwater wetland in the Seine
Estuary in northern France. It is in a heavily urbanized and industrialized
region and could be affected by atmospheric deposition and by
fluvial input of contaminants in water diverted from the Seine
River. To evaluate contaminant histories in the wetland and the
region, sediment cores were collected from two open-water ponds
in the Marais Vernier: the Grand-Mare, which was connected to
the Seine by a canal from 1950 to 1996, and the Petite Mare, which
has a small rural watershed. Diversions from the Seine to the
Grand-Mare increased sedimentation rates but mostly resulted in
low contaminant concentrations and loading rates, indicating that
the sediment from the Seine was predominantly brought upstream
by tidal currents from the estuary and was not from the watershed.
Atmospheric sources of metals dominate inputs to the Petite Mare;
however, runoff of metals from vehicle-related sources in the
watershed might contribute to the upward trends in concentrations
of Cr, Cu, and Zn. Estimates of atmospheric deposition using the
Petite Mare core are consistent with measured deposition in the
region and are mixed (similar for Hg and Pb; larger for Cd, Cu,
and Zn) compared with deposition estimated from sediment cores
in the northeastern United States. A local source of PAHs in the
watershed of the Petite Mare is indicated by higher concentrations,
higher accumulation rates, and a different, more petrogenic, PAH
assemblage than in the Grand-Mare. The study illustrates how diverse
sources and transport pathways can affect wetlands in industrial
regions and can be evaluated using sediment cores from the wetland
ponds.
Keywords: sediment; metals; PAHs; wetland; Seine Estuary; trends』
1 Introduction
2 Methods
3 Results and discussion
3.1 Age-dating and sediment focusing
3.2 Contaminant occurrence and trends
3.3 Contaminant sources to the Grand-Mare and Petite Mare
4 Conclusions
Acknowledgments
References