Fishery and wildlife managers face important challenges in reconciling recovery of historically over-harvested or extirpated populations of marine mammals with effective fisheries management. For example, the reestablishment of sea otters in British Columbia (B.C.) has had repercussions that led to one of the more interesting resource management problems involving commercial fisheries in Canada. As a case study, this paper reviews the history of sea otter exploitation and reintroduction in B.C., and discusses the nature and context of the problem today. Fisheries and marine mammals in Canada continue to be managed under overlapping legislative mandates and often with quite different goals. The case study highlights persistent social and institutional constraints on reconciling marine mammal-fishery conflicts. To reduce tensions and uncertainty, Fisheries and Oceans Canada should prioritize intensive marine mammal sampling programs for non-endangered species to disentangle fishing and predation effects, and fully implement Species At Risk Act and Fisheries Act measures to reduce uncertainty among increasingly diverse stakeholders.