Monitoring sources and processes driving trace metal bioaccumulation in oysters from a European macrotidal estuary over forty years: A multi-isotope approach

Cu values likely reflect vineyard runoff coupled with complexation in the dissolved phase. Pb isotope ratios reveal a gradual shift toward radiogenic values, shaped by diminishing industrial inputs and increasing lithogenic contributions. Together, these findings demonstrate that integrating hydrological data with multi-isotope analysis can disentangle source persistence from estuarine reactivity, offering a framework for interpreting long-term contamination dynamics under changing hydrological regimes.