In the light of increasing global energy demands and the need to reduce greenhouse gas emissions, attention has recently turned to the sea as a large and renewable source of kinetic energy. Developments for wave and tidal energy extraction currently exist more in potential than in actuality, but there is huge impetus from political, environmental and commercial interest groups for rapid growth of the marine renewable energy sector over the immediate future. Such growth will inevitably have repercussions for other stakeholders in the marine environment. Concerns from fishery interests are likely to centre on access to fishing grounds and on changes to the physical structure and ecological functioning of fish habitats. We examine the extent to which fishery and marine energy resources overlap in UK waters. We also consider in more general terms how marine spatial planning decisions may affect fishery yield and the spawning potential of target stocks. Results of these analyses point to the conclusion that the greatest potential for interaction between the marine energy and fishery sectors is at a local scale in inshore environments. The potential near‐field and far‐field environmental effects of energy conversion devices, and their repercussions for marine productivity are as yet poorly understood. Marine spatial planning decisions need to be informed by both ecological and socio‐economic considerations.