Environmental change has stressed wildlife co-management systems in the Arctic because parameters are changing more rapidly than traditional scientific monitoring can accommodate. Co-management systems have also been criticized for not fully integrating harvesters into the local management of resources. These two problems can be approached through the use of spatiallydefined human social units termed community clusters, which are based on the demographic or ecological units being managed. An examination of polar bear management in Nunavut Territory, Canada, shows that community clusters provide a forum to collect and analyse traditional ecological knowledge (TEK) over a geographic area that mirrors the management unit, providing detailed information of local conditions. This case study also provides examples of how instituting community clusters at a governance level provides harvesters with social space in which to develop their roles as managers, along the continuum from being powerless spectators to active, adaptive co-managers. Five steps for enhancing co-management systems through the inclusion of community clusters and their knowledge are: (1) the acceptance of TEK, science, the precautionary principle and the right of harvesters not to be constrained by overly-conservative management decisions; (2) data collection involving TEK and science, and a collaboration between the two; (3) institutionalization of community clusters for data collection; (4) institutionalization of community clusters in the management process; and (5) grass-roots initiatives to take advantage of the social space provided by the community cluster approach, in order to adapt the management to local conditions, and to effect policy changes at higher levels, so as to better meet local objectives.