This project is particularly pertinent in terms of assessing the status and seasonal movements of the North Sea population of harbour porpoises (as specified under 2a of the Annex of the Agreement and Action 7 of the Conservation Plan for harbour porpoises). The proposed surveys will improve existing methods with the combination of visual, acoustic and aerial methodologies. Overall, the work will aid the implementation of the Conservation Plan for Harbour Porpoises in the North Sea (Action Point 8 of the Triennium Work Plan). In addition, this project demonstrates close cooperation amongst governmental and non-governmental organisations working in partnership to improve knowledge and conservation of harbour porpoises within waters of the ASCOBANS agreement.