The report is focused on the research priorities pertaining to the implementation of the ‘maximum sustainable yield’ (MSY) and of the ‘ecosystem approach to fisheries’ (EAF). The MSY is first examined, taking account of its relevance as a management objective, of its link with maximum economic yield (MEY), and of its close relationship with ecosystem productivity and fishing capacity. Related research priorities are identified. In the second part, emphasis is put on EAF, a very challenge for fishery scientists. The extension of fisheries science towards an ecosystem dimension (including human activities) and the integration of uncertainty have opened up large fields of research. Priorities are presented by domain. Five principal areas of knowledge and related societal issues are identified: ecosystem, resources, exploitation, governance, methodology, the latter encompassing data collection.