Marine Protected Areas (MPA) are rapidly developing into an important part of the management of fish stocks and the protection of marine biodiversity because of their potential to protect entire functioning ecosystems and improve fishery harvests.  Historically, MPA have been directed towards the protection of coastal marine species with a sedentary adult phase because individuals remain inside reserves and are protected from anthropogenic disturbances.  Nevertheless, the politics and science of MPA are moving beyond these limits, and there is increasing interest in and pressure for the use of marine reserves as part of the management and conservation strategy for mobile demersal and pelagic species.  These species and their ecosystems present special biological, economic and governance challenges for the use of MPA.  Because mobile species are likely to move out of reserves, it is widely expected that MPA will offer less protection and benefits to these species.  However, the life histories of mobile marine species are often complex, involving a variety of migratory behavior patterns.  This spatio-temporal complexity offers the hope that reserves that protect particular life-history phases or critical habitats along migratory routes will offer benefits to these species.  Nevertheless, the negative consequences of fishing effort displacement may outweigh protection benefits if fishing mortality increases outside of reserves. 

 In the absence of scientific study of how the complex spatial dynamics of mobile marine species affects MPA functioning, there is a great risk that ineffective management decisions will be taken based on existing knowledge relating to sedentary species and/or terrestrial management.  This project addresses this urgent need through a comprehensive examination of the problem from a variety of complimentary angles, including (i) the collection of basic empirical data needed to understand the movement and interactions of fish species, (ii) the development and use of several spatially-explicit MPA models, including individually-based, single-species, ecosystem and bio-economic approaches, to test competing strategies (MPA and other forms of management) against a variety of fish life-history types, and (iii) the examination of the governance implications of large scale marine reserves in national and international waters.  We apply these methods in three different systems, the Gulf of Lions, South Africa and the Indian Ocean, that contain high-value and/or important by-catch species with different movement behavior.  All three areas have expressed a strong interest in pursuing a science-based examination of the potential effects of MPA.  Through this comprehensive study, we aim to provide the information that management authorities need now while the topic of MPA for demersal and pelagic species is relatively young and critical decisions have yet to be made.