The Chilean government has introduced a co-management policy that grants ten-itorial user tights to organised groups of artisanal fishers with the goal of achieving sustainable coastal fisheries. This management measure aims to encourage a positive change in fishers' behavioural patterns and to transform fishing operations into small business enterp1ises managed by fishers. This study analyses the human dimensions of the policy with special emphasis on the social, cultural and economic variability of participating a1tisanal fishers. Fishers' attitudes towards conse1vation and co-management va1y significantly between individuals. Fishers also respond in different ways to the financial challenge of managing resources under teITitorial user rights policies. These differences indicated the existence of different worldviews that stmcture fishers' behaviour toward the marine environment and its management. Fishers' attitudes and financial adaptation strategies coITelated best with fishers' livelihood characteristics. Additionally fishers' specific attitudes towards environmental quality seemed to be shaped favourably by fishers being engaged with co-management, as these aspects would be related to quality control operating w ithin international markets. Results also suggest that a simple review of co-management application statistics and th e accompanying official documentation does not identify the problems with the policy. Historical fishing sites are becoming scarce, conflict between fishers is rising and the costs of enforcing tenit01ial user rights increments. Under these circumstances, fishers' engagement with co-management relate to power stmggles between fishing groups, which acquire specific sto1y-lines to legitimize claims when adapting to conditions generated by the policy. Power inequalities between fishers could jeopardize the use of tenit01ial user rights and therefore must be considered in co-managements future developments. The thesis also highlights the importance of understanding the impact of implementing co-management over traditionally managed ecosystems. In doing so the study advocates for the need to include derogations in policies for systems that offer similar benefits to those achievable by co-management. The human dimension is an imp01tant aspect of co-management implementation. It offers a way to understand fishers who engage in the activities to be regulated, including their motivations, attitudes, culture and social and economic situations. In view of this knowledge policy makers gain new insights into the problems that arise while attempting to co-manage resources and therefore might consider new mechanisms for consultation, better adaptation of the policy to local realities and eventually a move towards an adaptive f01m of co-management.