Due to degrading marine environments and loss of biological diversity, marine protected areas (MPAs) are increasingly utilized to protect living marine resources. Unfortunately, effective management of these areas is often held back by conflicts between conservation and user interests, together with the limited knowledge on the functioning of marine ecosystems. As a way of reducing tensions and closing knowledge-gaps, collaborative arrangements between stakeholders and decision-makers are increasingly sought and comprised into policy guiding the establishment of MPAs. Despite the rising scholarly interest in these matters, little has been written about whether the commitments to collaboration expressed in policy are fulfilled in practice. Pursuing this question, the purpose of this thesis is to examine the resemblance between policy and practice in the context of collaboration between decision-makers and stakeholders during the establishment of MPAs. A case study of the Swedish Skånska Kattegatt, a marine protected area on the west coast of Sweden, reveals a discrepancy between policy and practice during the early stages of the process, regarding the construction of the knowledge base of the decision. The study identifies a possible cause to be lacking resources at the County administrative board responsible for the establishment, a crucial aspect to which more attention needs to be directed in similar, future settings.