Background The Celtic Seas Marine Region (CSMR) encompasses the western seaboard of the UK and Republic of Ireland, the coasts and territorial waters to the north of Scotland and south to Brittany in northern France. The European Atlas of the Seas describes this area as a very windy stretch of water that has long been a busy shipping area with intensive fishing activity – small-scale in the south and deep-sea fishing in the north. Over the past 20 years, aquaculture (fish and sea-food farms) has taken off more strongly and diversified more than in other marine regions. In coastal areas, there is an active and varied tourist industry. The Celtic Seas have a wide range of marine habitats supporting a diversity of marine wildlife including whales, dolphins and porpoises, seals, internationally important populations of seabirds, fish and benthic species. In addition, the CSMR supports some of the major migratory fish stocks of the north-east Atlantic including Atlantic mackerel, blue whiting and sea bass. This northern part of the north-east Atlantic region has a strong maritime heritage and wide range of maritime users including maritime transport and cabling, and natural resources (e.g. aggregates, offshore wind). As pressures increase for use of the marine space and natural resources, there is a need for better coordination and communication between users and the relevant governing bodies. Objectives The CSP project will support the implementation of EU environmental and maritime policy, using a stakeholder-led approach to contribute to the development of marine strategies, particularly under the Marine Strategy Framework Directive (MSFD) for the achievement of good environmental status of marine waters. The project will develop appropriate stakeholder engagement mechanisms and build stakeholders’ capacities to enable them to support delivery of integrated management, to reduce conflicts between coastal and marine-resource users, and to enhance the environmental, economic and social sustainability of the CSMR. Effective stakeholder engagement will increase understanding, buy-in and compliance, reducing the need for enforcement and layers of regulation. To build stakeholder engagement, the project will hold three Celtic Seas Conferences. Capacity building will involve the development and demonstration of a number of practical tools and approaches that contribute to ecosystems-based management approaches. Through the development and evaluation of these tools, this project will offers a significant opportunity to explore good practice approaches towards the MSFD by improving coordination for cross-border coastal and marine planning and management. The tools and approaches demonstrated will include testing and evaluation of best practice approaches to conflict resolution and co-location of activities in the marine environment; developing transboundary governance structures; using Integrated Coastal Zone Management (ICZM) principles to support the implementation of the MSFD; and the development of sectoral action plans to aid practical implementation of ecosystems-based management. Expected results The project will deliver the following results by 2016: CSMR stakeholders will be familiar with the requirements of the MSFD and will be willing to cooperate and coordinate activities; Transboundary governance approaches led by stakeholders will demonstrate effective use of the ecosystems approach for cross-border marine management; Good practice approaches will have been developed and applied in the relevant sectors to mobilise capacity to support sustainable management of the CSMR; and Techniques and methods will have been developed to help monitor good environmental status in the CSMR.