Could seagrass meadows be a natural, local remedy for ocean acidification? This project explores the idea by documenting pH, alkalinity and other properties of seawater at seagrass meadows and control sites in Tomales Bay, a major shellfish-growing center in the state. Three major questions will be addressed: 1) To what extent does carbonate chemistry within the bay vary because of geomorphology and hydrology? 2) To what degree do seagrasses, by up-taking and releasing carbon dioxide, alter local carbonate chemistry? And, 3) Do results support the idea of using expanded seagrasses to locally buffer carbonate chemistry and hence offset ocean acidification? Results from this project will be shared with stakeholder groups at yearly workshops, convened by the project’s lead investigator, and may provide crucial information to help protect the region’s shellfish farms from climate change. The project is a collaboration with the Hog Island Oyster Company.