Effect of root metabolism on the post-depositional mobilization of mercury in salt marsh soils

Abstract

Salt marsh soils are an efficient sink for trace metals associated with particulate material in tidal waters (Nixon, 1980; Long & Mason, 1983) and have been proposed as monitors for trace metal contamination in coastal areas (Taylor, 1979), on the basis that vertical profiles provide a record of loading rates. However, the complex nature of the biogeochemicial processes occurring in these soils, may prevent this use, since post-depositional mobilization of some trace metals may occur, resulting in their release to pore water, vertical movement through the soil column and exchange with overlying waters (French, 1993; Rasmussen, 1994).