The impact of coal production on the sediment record of the Severn Estuary

A link between historical coal production and sediment coal concentrations in saltmarsh sediments is demonstrated for the Severn Estuary, southwest Britain. It is clear that whilst coal production has varied in accordance with industrial demand, the environmental impact has been manifested in a corresponding increase in environmental pollution. Furthermore, the transfer of coal between production site and estuarine sediment has introduced a lag period into the transfer mechanism, argued to be of different periods by different authors, but generally agreed to exist. With coal production at the present time effectively zero, it can be argued that new input has to come from contaminated sediments already present within the Estuary. Current estimates indicate that the intertidal mudflat sediments of the contemporary system currently hold around 105–106 tonnes of coal, whilst erosion of the three marshes studied here suggest an input of coal from this source ranging from 76 to 134 tonnes a−1. As a consequence, both contemporary mudflats and saltmarshes must both be regarded as potential future coal pollution sources.