The Celtic Sea marine ecosystem is an area of diverse wildlife and important ecological activity. It is also one of the most heavily used bodies of water in the world of with multiple sectors including industry, shipping, commercial fishing and coastal recreation competing for space and resources. Like oceans and seas globally, this region is experiencing pressures due to increasing human activity. In response to this growing problem, the European Commission LIFE+ programme funded a project called Partnerships Involving Stakeholders in the Celtic Sea Eco-System (PISCES) produce a set of stakeholder-led guidelines for an ecosystem-based approach to management of activities in the area.Current EU-wide marine management policies rely on effective application of an ecosystem-based approach (e.g., the EU Marine Strategy Framework Directive; the Common Fisheries Policy). PISCES is a pioneering project in that it is translating EU maritime policy into practical outputs for multiple sectors and across a multinational area encompassing four countries: the UK, Ireland, France and Spain. This three-year project, which began at the end of 2009, identifies the key players in the Celtic Sea representing all major human uses and impacts, and builds successful stakeholder partnerships through a series of workshops whilst also facilitating additional interactions in order to maximise the out-reach and impact of the practical guidelines. Stakeholders include the fishing and aquaculture industries, marine renewable energy companies, shipping, oil, gas and aggregate extraction industries, ports, environmental agencies, coastal tourism and recreation industries, as well as key policy makers from the four countries.