Variation in species’ tolerance to climate change conditions may result in changes to the strength of ecological relationships that structure and maintain the stability of ecosystems. I evaluated how historical (1982-2019) and projected (2030 through end-of-century) warming in the Eastern Bering Sea (EBS), Alaska, affects predator-prey interactions for some of the most commercially valuable fisheries in the U.S. These potential shifts in predator-prey interactions will not only impact the structure of ecological communities, but also the human communities that rely on these resources. The EBS is the largest marine ecosystem in Alaska and is already transitioning from an arctic to a subarctic system. Using a species distribution modeling approach for seven species and an ensemble of 18 statistically downscaled climate models, I project how further temperature increases will affect the geographic similarity between predator and prey populations, the proportion of locations where predator and prey co-occur, and their encounter rates. Projections suggest predator-prey encounter rates in historic prey refuges will increase, intensifying predation pressure for prey, while projections of decreasing encounter rates in the outer shelf and southern EBS indicate predators may not have sufficient prey to maintain high abundance in these regions. This study establishes that the strength of predator-prey relationships will be impacted by climate change conditions, potentially altering the relative importance of predators and prey in the system and reshaping the structure of the EBS trophic web.
Ellen Willis-Norton 