Evaluating the Evolving Ocean Acidification Risk to Dungeness Crab: Time-Series Observations and Modeling on the Olympic Coast, Washington, USA

The state of Washington’s Olympic coast is home to four US coastal treaty tribes who have relied on the region’s rich marine resources since time immemorial. The region is characterized by large dynamic ranges of physical and biogeochemical oceanographic parameters, particularly during the upwelling season (April–September). Here, we present novel estimates of ocean acidification metrics—pH and calcium carbonate saturation states (Ω)—representing pre-industrial, present-day (using 2010 as the index year), and near-future (2030) conditions. We compare these new estimates of past, present, and near-future ocean acidification status and seasonality to published end-of-century (2100) ocean acidification projections under a high CO2 emissions scenario, and also to sensitivity information for Dungeness crab, a regionally important subsistence and commercial fishery species projected to show strong declines in fisheries yields and revenues later this century.