title: Supporting Risk Assessment: Accounting for Indirect Risk to Ecosystem Components.
abstract: The multi-scalar complexity of social-ecological systems makes it challenging to quantify impacts from human activities on ecosystems, inspiring risk-based approaches to assessments of potential effects of human activities on valued ecosystem components. Risk assessments do not commonly include the risk from indirect effects as mediated via habitat and prey. In this case study from British Columbia, Canada, we illustrate how such "indirect risks" can be incorporated into risk assessments for seventeen ecosystem components. We ask whether (i) the addition of indirect risk changes the at-risk ranking of the seventeen ecosystem components and if (ii) risk scores correlate with trophic prey and habitat linkages in the food web. Even with conservative assumptions about the transfer of impacts or risks from prey species and habitats, the addition of indirect risks in the cumulative risk score changes the ranking of priorities for management. In particular, resident orca, Steller sea lion, and Pacific herring all increase in relative risk, more closely aligning these species with their "at-risk status" designations. Risk assessments are not a replacement for impact assessments, but-by considering the potential for indirect risks as we demonstrate here-they offer a crucial complementary perspective for the management of ecosystems and the organisms within.
authors.affiliation: Institute for Resources, Environment and Sustainability, University of British Columbia, Vancouver, British Columbia, Canada.|North Pacific Marine Science Organization (PICES), Sidney, British Columbia, Canada.
authors.forename: Cathryn Clarke
authors.identifier: http://orcid.org/0000-0002-6868-5371
authors.initials: CC
authors.lastname: Murray
authors.affiliation: Institute for Resources, Environment and Sustainability, University of British Columbia, Vancouver, British Columbia, Canada.|Center for Ocean Solutions, Monterey, California, United States of America.
authors.forename: Megan E
authors.initials: ME
authors.lastname: Mach
authors.affiliation: Center for Ocean Solutions, Monterey, California, United States of America.
authors.forename: Rebecca G
authors.initials: RG
authors.lastname: Martone
authors.affiliation: Institute for Resources, Environment and Sustainability, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Gerald G
authors.initials: GG
authors.lastname: Singh
authors.affiliation: Fisheries & Oceans Canada, Institute for Ocean Sciences, Sidney, British Columbia, Canada.
authors.forename: Miriam
authors.initials: M
authors.lastname: O
authors.affiliation: Institute for Resources, Environment and Sustainability, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Kai M A
authors.initials: KM
authors.lastname: Chan
mesh_terms: D000818:Animals; D017753:Ecosystem; D020387:Food Chain; D008386:Marine Biology; D011235:Predatory Behavior; D018570:Risk Assessment