This report is a contribution to the Strategic Environmental Assessment (SEA6) conducted by the Department of Trade and Industry (now Department of Energy and Climate Change). In order to understand and prioritise the nature of prehistoric archaeological sites, which might occur on the sea floor, this report considers the context of all the adjacent land masses, including the Irish Republic, and in the south the Celtic Sea and western Channel. Prehistoric submarine archaeological remains back to a date of about 225,000 years ago, Palaeolithic, Mesolithic and Neolithic, could occur with low probability in many parts of the SEA6 area.
Palaeolithic archaeological sites as old as 225,000 years Before Present (BP) occur at locations on the Welsh coast, with a great density of sites from the later Mesolithic and Neolithic. Some sites therefore pre-date the last interglacial high sea level, and although they were covered by the Devensian ice sheet, material inside caves survived.
Pipe entrenching is the process in the oil and gas industry most likely to disturb prehistoric archaeological deposits. Commercial site investigation using acoustics and coring could provide beneficial new archaeological data. The paper concludes with tentative suggestions for discussion of protocols and a reporting regime.