The macrotidal Seine estuary (France) is one of the most man-altered and mercury-
contaminated European estuaries. Molecular quantification by competitive PCR has shown
that the highest quantities of Gram-negative merA genes in intertidal freshwater mudflat
sediments are located in recent sediment deposits independently of mercury concentrations,
suggesting that particle-attached allochtonous mercury-resistant merA bacteria are
deposited on mudflat surfaces. To investigate this hypothesis, a microcosm experiment was …