Maxwell, Sara M2; Hazen, Elliott L2; Bograd, Steven J2; Halpern, Benjamin S2; Breed, Greg A2; Nickel, barry2; Teutschel, Nicole M2; Crowder, Larry B2; Benson, Scott2; Dutton, Peter H2; Bailey, Helen2; Kappes, Michelle A2; Kuhn, Carey E2; Weise, Michael J2; Mate, Bruce2; Shaffer, Scott A2; Hassrick, Jason L2; Henry, Robert W2; Irvine, Ladd2; McDonald, Birgitte3; Robinson, Patrick W2; Block, Barbara A2; Costa, Daniel P2
1 Department of Bioscience - Zoophysiology, Department of Bioscience, Science and Technology, Aarhus University2 unknown3 Department of Bioscience - Zoophysiology, Department of Bioscience, Science and Technology, Aarhus University
Stressors associated with human activities interact in complex ways to affect marine ecosystems, yet we lack spatially explicit assessments of cumulative impacts on ecologically and economically key components such as marine predators. Here we develop a metric of cumulative utilization and impact (CUI) on marine predators by combining electronic tracking data of eight protected predator species (n=685 individuals) in the California Current Ecosystem with data on 24 anthropogenic stressors. We show significant variation in CUI with some of the highest impacts within US National Marine Sanctuaries. High variation in underlying species and cumulative impact distributions means that neither alone is sufficient for effective spatial management. Instead, comprehensive management approaches accounting for both cumulative human impacts and trade-offs among multiple stressors must be applied in planning the use of marine resources.