Cascading social-ecological costs and benefits triggered by a recovering keystone predator

Predator recovery often leads to ecosystem change that can trigger conflicts with more recently established human activities. In the eastern North Pacific, recovering sea otters are transforming coastal systems by reducing populations of benthic invertebrates and releasing kelp forests from grazing pressure. These changes threaten established shellfish fisheries and modify a variety of other ecosystem services. The diverse social and economic consequences of this trophic cascade are unknown, particularly across large regions. We developed and applied a trophic model to predict these impacts on four ecosystem services. Results suggest sea otter presence yields 37% more total ecosystem biomass annually, increasing the value of finfish (+9.4 M$), carbon sequestration (+2.2 M$), and ecotourism (+42.0 M$). To the extent these benefits are realized, they will exceed the annual loss to invertebrate fisheries (-7.3 M$). Recovery of keystone predators thus not only restores ecosystems, but can also affect a range of social, economic, and ecological benefits for associated communities.Science, Faculty ofNon UBCEarth, Ocean and Atmospheric Sciences, Department ofOceans and Fisheries, Institute for theResources, Environment and Sustainability (IRES), Institute forZoology, Department ofReviewedFacultyResearcherPostdoctora