Understanding Ecosystem-Scale Impacts from Ocean Acidification; A California Current Atlantis Modeling Case Study

Ocean acidification is gaining increasing attention in the literature with large advances in our understanding of potential impacts at the species level; however, the realized impact in the food web and ecosystem context remains largely unknown. Advancing our understanding of ecosystem responses is essential in order to plan for change and an ecosystem model such as Atlantis is a valuable tool to use in such circumstances. Here we investigate ecosystem-scale impacts from ocean acidification using the Atlantis ecosystem model for the California Current. The California Current is an ideal study system, as low levels of carbonate saturation already exist within the near-shore environment due to upwelling, and even lower levels are expected in the future. It is also an area that provides large fishery revenues. Using  projections of future ocean conditions, we measured the impact of ocean acidification in the California Current, with particular focus on key species in the food web that serve as either an important fishery resource (Pacific hake, Dungeness crab) or play a key ecological role (krill). We found strong food web effects that have an influence on future catch, with strong variation between regions and fisheries, due to expected patchiness and latitudinal trends in acidification.