Marine protected areas (MPAs) are a promising tool for preventing overexploitation of marine biological resources. However, there are still few MPAs in temperate waters. Recently, the Norwegian Directorate of Fisheries has encouraged the establishment of MPAs in Skagerrak. A working group at the Norwegian Institute of Marine Research has proposed three sites for establishment of MPAs, primarily as lobster refugia, in cooperation with local fishers. The Norwegian lobster fishery has gradually decreased ove r the last 50 years. This project aims to test if MPAs can help to rebuild the lobster population. We will examine biotic change as well as study aspects of lobster ecology with relevance to design of MPAs. The project involves both observational and expe rimental studies relevant to MPA theory. We anticipate that the proposed reserves can act as important model systems for a broad-scale establishment of MPAs in temperate waters. We expect that the unique data-set on lobster from the Swedish reserve will g enerate fundamental knowledge on lobster demography, which will be important for designing future reserves.