Trace metal contamination of Beaufort’s Dyke, North Channel, Irish Sea: A legacy of ordnance disposal

Beaufort’s Dyke is a disused ordnance disposal ground within the North Channel of the Irish Sea. Over 1 million tonnes of ordnance were disposed of in the dyke over a 40year period representing a substantial volume of trace metal pollutants introduced to the seabed. Utilising particle transport modelling software we simulated the potential transport of metal particles from Beaufort’s Dyke over a 3month period. This demonstrated that Beaufort’s Dyke has the potential to act as a source for trace metal contamination to areas beyond the submarine valley. Trace metal analysis of sediments from the Dyke and surrounding National Marine Monitoring Programme areas demonstrate that the Dyke is not the most contaminated site in the region. Particle transport modelling enables the transport pathways of trace metal contaminants to be predicted. Implementation of the technique in other munitions disposal grounds will provide valuable information for the selection of monitoring stations.