What is acidification Ocean Acidification (OA) is a pressing environmental concern that affects the health of our oceans and the people who use them. Overview Increased atmospheric carbon dioxide (CO₂) levels, caused by the burning of fossil fuels and deforestation, is the primary driver of a process termed ocean acidification, where the addition of CO₂ to the surface ocean acts to increase seawater acidity and lower pH. Why It Matters Carbon dioxide gas dissolves so readily in seawater that approximately one quarter of human caused CO₂ emissions become sequestered in the ocean. Once in the ocean, CO₂ combines with water to form a weak acid, resulting in a change in the chemistry of the sea. What Lies Ahead The Federal Ocean and Acidification Research Monitoring (FOARAM) Act, reauthorized by Congress in 2022, strengthens investments in acidification research, monitoring, and studies on socioeconomic impacts. Coastal Acidification Networks, like MACAN, NECAN, and SOCAN, provide an important bridge, connecting scientists, local government, and industry members to address acidification impacts at the regional level. At the local level, Mid-Atlantic states are taking a closer look at acidification’s implications in their waters. Learn more about state-led OA action planning initiatives here. Acidification Will Continue to Influence All Areas of the Mid-Atlantic, From its Tidal Estuaries to Deep Sea Ecosystems 1 Acidification will continue to influence all areas of the Mid-Atlantic, from its tidal estuaries to deep sea ecosystems. The cooler, less salty waters of the upper Mid-Atlantic are particularly susceptible to ocean acidification, making reductions in the survival, calcification, growth, development, and abundance of marine organisms more likely. The organisms impacted most negatively and directly will likely be calcified algae, corals, mollusks, and echinoderms. Crustaceans, fleshy algae, seagrasses, and diatoms may be less directly affected or may even benefit from acidification. Even still, questions regarding food web impacts that may indirectly negatively impact all species remain. Acidification May Hamper Efforts to Protect and Preserve the Mid-Atlantic’s Cultural Underwater Resources 1 The “Ghost Ship fleet” of Mallows Bay-Potomac River National Marine Sanctuary is one such resource. Anticipating damage to metal structures on the ships and other potential impacts, sanctuary managers are beginning to address climate change through their sanctuary management plans. As outlined in the report, Climate Change Impacts: Mallows Bay-Potomac River National Marine Sanctuary, strong partnerships between NOAA, the state of Maryland, and local organizations have been key to establishing a water monitoring network and supporting research on acidification and other climate stressors. Combating Acidification Won’t Be Easy, But Scientists, Governments, and NGOs Are Working to Identify Approaches to Help Mitigation Changing behavior and advancing technologies to decrease the carbon dioxide that causes acidification. Remediation Taking steps to lessen the acidity of water, such as planting eelgrasses that take up carbon dioxide. Adaptation Making changes in response to the symptoms of acidification, such as breeding shellfish that are more resistant to acidified waters. Innovative Ideas for Mitigation, Remediation, and Adaptation of Acidified Waters Will Continue to Evolve MACAN can help to guide resources for research in mitigation, remediation, and adaptation by collectively identifying the most critical research gaps.