Barriers and opportunities for the effective management of cumulative effects in salmon ecosystems in British Columbia, Canada

The cumulative effects of climate change and human activities pose major challenges for environmental management, a problem exemplified by Pacific salmon ecosystems. We offer an integrative treatment of both the science and policy levers of cumulative effects and reveal the sheer complexity of effective governance of salmon ecosystems in British Columbia, Canada. We then present and examine a hypothetical conceptualization of cumulative effects and their governance in salmon ecosystems to highlight several barriers and opportunities. We find that the progressive degradation of many salmon habitats appears to be enabled by the current policy approach through scarce monitoring, ineffective assessment, lack of legal limits, and isolated decision-making. At the same time, climate change magnifies the urgency of effective management as human activities act cumulatively with climate change impacts. However, our synthesis also highlights opportunities with existing but underused policy levers within Crown and Indigenous governance, as well as local co-governance arrangements, that could improve salmon ecosystem management. Although positive steps have been made toward managing several stressors, the current challenges facing Pacific salmon underscore the need for a fundamental shift in the treatment of cumulative effects.