Seasonality and Life History Complexity Determine Vulnerability of Dungeness Crab to Multiple Climate Stressors
Halle M. Berger, Samantha Siedlecki, Catherine M. Matassa, Simone R. Alin, Isaac C. Kaplan, Emma E. Hodgson, Darren Pilcher, Emily Norton, Jan Newton
Abstract
Abstract Scaling climate change impacts from individual responses to population‐level vulnerability is a pressing challenge for scientists and society. We assessed vulnerability of the most valuable fished species in the Northwest U.S.—Dungeness crab—to climate stressors using a novel combination of ocean, population, and larval transport models with stage‐specific consequences of ocean acidification, hypoxia, and warming. Integration across pelagic and benthic life stages revealed increased population‐level vulnerability to each stressor by 2100 under RCP 8.5. Under future conditions, chronic vulnerability to low pH emerged year‐round for all life stages, whereas vulnerability to low oxygen continued to be acute, developing seasonally and impacting adults, which are critical to population growth. Our results demonstrate how ontogenetic habitat shifts and seasonal ocean conditions interactively impact population‐level vulnerability. Because most valuable U.S. fisheries rely on species with complex life cycles in seasonal seas, chronic and acute perspectives are necessary to assess population‐level vulnerability to climate change.