A comparison of the vulnerability of marine ecosystems to anthropogenic stressors

Cumulative effects assessments are increasingly required for resource management, marine spatial planning, and ecosystem-based management. A key step in a cumulative effects assessment is to determine the vulnerability of ecosystem components to stressors, which can be achieved through a vulnerability assessment. However, not all studies define vulnerability in the same way, which can lead to variable and incompatible results. For example, while many cumulative impact mapping studies use expert-derived scoring based on the variables of spatial scale, frequency, trophic impact, percentage change, and recovery time (e.g., Teck et al 2010), others, such as DFO’s Ecological Risk Assessment Framework (O et al 2015), use area, depth, temporal extent, intensity, frequency, acute change, chronic change, and recovery. In order to evaluate whether assessment outcomes vary based on the vulnerability criteria used, we synthesized vulnerability assessments, and compared rankings to examine commonalities and differences. We then explored how the definition and calculation of vulnerability and the goal of the assessment may have affected the rankings of habitats, species, and stressors. This comparison of vulnerability definitions and ranking across different assessments will advance the understanding of cumulative effects and the management of the risk of stressors, and inform our work to create a vulnerability matrix specifically for Canada’s coasts. The refinement of vulnerability assessments will be a key component in future cumulative effects assessments