Award: OCE-1600230

This project documented the role of apex predators and environmental drivers on changes in Southeast Alaska nearshore marine resources using an interdisciplinary approach that integrated social and ecological studies. Humans and sea otters are apex predators in this system, and their interrelationship is complex. The extermination of sea otters during the fur trade resulted in their absence for hundreds of years, and during this time nearshore marine resources likely increased in abundance. We found that when sea otters recolonize, they consume and reduce the abundance of shellfish, such as crabs, sea urchins, clams and abalone, causing cascading effects in nearshore ecosystems and competing with humans for these popular fished species. Coastal Alaska Natives hunt sea otters, with reciprocal feedbacks. Our research documents cascading effects of sea otters in eelgrass and kelp communities. Highlights of this work include an intriguing positive association between sea otters and eelgrass, potentially mediated through disturbance of habitat and removal of clams that could compete for space. Within kelp habitats, sea otters increase kelp and could benefit abalone through keeping sea urchins at low densities. Fish in eelgrass and kelp habitats may benefit from sea otters increasing the abundance of these structured vegetated habitats. Our research has local and broad scientific significance because of the local and global value of apex predators and the contribution of their ecosystem services to sustainability. Human removal of apex predators is one of the most pervasive effects on nature, and this research can inform societal decisions on how to manage these apex predators in the future. We collaborated with Alaska Native communities in this project through consultation with community members and leaders about project goals and results. We shared our results broadly with a wide diversity of stakeholders and hope our results will be used to inform future management to improve well-being and sustainability of rural coastal communities. Last Modified: 06/27/2023 Submitted by: Ginny L Eckert