Sustainable ecosystem management relies on a diverse and multi-faceted knowledge system in which techniques are continuously updated to reflect current understanding and needs. The challenge is to minimize delay as ideas flow from intent through scientific capability, and finally to implementation to achieve desired outcomes. The best way to do this is by setting the stage for the flow of knowledge between researchers, policy makers, and resource managers. The cultural differences between these groups magnify the challenge. This paper highlights the importance of the tacit dimension of knowledge, and how this renders the concept of knowledge transfer much less useful than the concepts of information transfer and technology transfer. Instead of knowledge transfer, we propose that "co-production" of knowledge through collaborative learning between "experts" and "users" is a more suitable approach to building a knowledge system for the sustainable management of ecosystems. Keywords: communities of practice, knowledge interface, knowledge transfer, science-management divide, R&D programs, shared understanding, tacit knowledge.