Assessing vulnerability of Arctic fish species to climate change.

Climate change is impacting Arctic marine ecosystems at faster rates than the global average, challenging the management and conservation of biodiversity and living marine resources. This study examined the climate risks and vulnerabilities of 21 Arctic fish species occurring in the western Canadian Arctic using a fuzzy logic approach. Identified climatic hazards to marine species and their habitats are increasing temperature, decreasing sea ice cover, freshening, decreasing oxygen concentration, and acidification. The nature of these hazards included changes in mean conditions by 2050 (2041-2060), compared to the historical period (1979-2015 average) simulated from a regional coupled ice-ocean biogeochemical model and two coupled Earth system models under low and high emissions scenarios. A spatially-explicit algorithm was used to assess the risk and vulnerability in the Beaufort Sea shelf and slope and Amundsen Gulf (BS-AG) based on the species' biological traits, biogeography and their exposure to climatic hazards. The results indicated high to very high exposure and risk of climate impacts across the ecosystem variables. Specifically, shallow areas were projected to be simultaneously exposed to more intense warming, reduced sea ice coverage, freshening, and acidification relative to the regional averages. In addition, for species occurring in the BS-AG, low adaptability and high sensitivity to climate hazards was identified. These applied tools and evaluations can inform marine spatial planning and climate adaptation efforts to help achieve conservation objectives and sustain ecosystem and community health in a changing Arctic climate. Supplementary Information: The online version contains supplementary material available at 10.1007/s44289-025-00056-7.