This is a study of a community-based fishery on the Rovuma River that forms the border between Mozambique and Tanzania. We postulate a relationship between social capital and community-based governance over access to and the use of the fish resource. In historical times social capital was high and community-based governance regulated access to and use of the fishery as a common property resource. Transforming forces particularly colonial administration, advocating Christianity, war and an emerging market economy undermined social capital, which in turn affected community-based governance. The deconstruction of social capital has resulted in attitudes and behaviours that challenge governance processes with dire consequences for sustainable resource utilisation. Harvesting of fish stocks occurs at levels that are no longer sustainable and inappropriate practices are being adopted. While the Mozambique government policy promotes community-based fisheries management in artisanal fisheries, we argue that under current conditions of ineffective community-based governance, a strong focus on reconstruction of social capital will be required before a community-based resource management process can be effectively implemented. The findings are discussed in the context of resilience in social ecological systems. We suggest that given the historical context in which community-based natural resource management is promoted within southern Africa such a focus may have wide relevance.