Prosjektsammendrag: The aim of this project is to study marine protected areas (MPAs) as a fisheries management tool when emphasis is put on two important aspects: management costs and uncertainty. Although often ignored, management costs make up a substantial part of the c atch value in many countries. It may however be assumed that the costs of managing a fishery will vary with the regime chosen.We wish to investigate how the inclusion of management costs affects the results from studies of optimal management strategies. T he effect MPAs have on the management costs is closely related to ecological uncertainty. MPAs have been found to reduce the exposed to a shock in recruitment. If the use of MPAs cause substantial reduction in the risk of stock depletion, it could expecte d that management costs would decline as the need for surveillance and monitoring decreases accordingly. We therefore also plan to include uncertainty in our study of MPAs as a fisheries management tool. Applications will be on cod and shrshrimp in the Barents sea.