This report is a contribution to Strategic Environmental Assessment SEA2 conducted by the Department of Trade and Industry (now Department of Energy and Climate Change) and it considers human activities in the North Sea which might have an impact on, or themselves be affected by, further oil and gas developments in the SEA2 areas. The SEA2 areas cover the Northern North Sea (NNS), the Central North Sea (CNS) and the Southern North Sea (SNS). The activities include shipping, energy (both existing oil and gas developments and renewable energy), telecommunications, military activities, waste disposal, dredging and aggregate extraction, marine archaeological sites and wrecks. Commercial fishing is the subject of a separate report.