Supporting Risk Assessment: Accounting for Indirect Risk to Ecosystem Components

Area of Science:

• Ecosystem risk assessment
• Social-ecological systems
• Conservation biology

Background:

• Quantifying human impacts on complex social-ecological systems is challenging.
• Traditional risk assessments often overlook indirect effects mediated through habitats and prey.
• Understanding these indirect risks is crucial for effective ecosystem management.

Purpose of the Study:

• To incorporate indirect risks into ecosystem risk assessments.
• To evaluate how indirect risks alter the at-risk ranking of ecosystem components.
• To determine if risk scores correlate with food web linkages.

Main Methods:

• Case study conducted in British Columbia, Canada.
• Risk assessment framework extended to include indirect effects.
• Analysis of seventeen ecosystem components, considering trophic and habitat connections.

Main Results:

• Addition of indirect risks changed the relative at-risk ranking of ecosystem components.
• Species such as resident orca, Steller sea lion, and Pacific herring showed increased risk.
• Updated rankings better aligned species' risk levels with their conservation status.

Conclusions:

• Indirect risk assessment provides a vital complementary perspective to impact assessments.
• Considering indirect effects is essential for prioritizing management actions in ecosystems.
• This approach enhances the accuracy of risk assessments for ecosystem management.