Ocean acidification is a complex issue that is being studied and addressed from several viewpoints, in various locations, and for different issues. Within the sanctuary system, sanctuary sites across the country and United States territories are studying how this change in ocean chemistry will and already is affecting their sites. Some sites are being hit harder than others at the moment, but all are studying and preparing for what is to come.
Learn how our ocean is absorbing increasingly more carbon dioxide from the atmosphere, leading to lower pH and an increase in acidity. Ocean acidification is fundamentally changing the chemistry of the world’s ocean and threatening our marine resources.
Increased levels of carbon dioxide in the atmosphere have further increased the dissolved carbon dioxide concentration in seawater, reducing the pH and increasing the acidity of the ocean. As a result, the mobility, growth, and reproduction of calcium carbonate forming organisms (e.g., corals, invertebrates, plankton, etc.) will be affected, which is expected to have cascading effects throughout the food web.
National marine sanctuaries and partner organizations monitor ocean conditions and assess the impacts of a changing climate on ecosystems and coastal communities. Sanctuaries serve as sentinel sites where the impacts of climate change and ocean acidification can be studied.
Research conducted by sanctuary scientists and partners provides critical information to address existing and emerging resource conservation and management issues. Find the overview of research highlights and some of the research activities completed or ongoing at Olympic Coast National Marine Sanctuary here.
Human-induced increases in greenhouse gas emissions are contributing to global-scale warming and are associated with acidification of the world's ocean. Climate change is projected to profoundly affect coastal and marine ecosystems on a global scale, and we expect these consequences to manifest in the Channel Islands sanctuary as well.
In collaboration with research partners, the sanctuary will work to monitor physical and biological indicators of climate change, identify vulnerable natural and cultural resources, understand climate drivers and stressors, and more.
Along with extreme temperature fluctuations from a changing climate, ocean acidification may also affect coral reefs in the Florida Keys as atmospheric carbon dioxide levels continue to increase. Ocean acidification could prompt a chain reaction of impacts through the marine food web, beginning with larval fish, shellfish, and corals, cutting valuable ecosystem services provided by coral reefs such as food security, tourism, shoreline protection, and biodiversity.
Within Flower Garden Banks National Marine Sanctuary, there are corals that are found throughout the deeper areas of the sanctuary, as well as throughout the reefs and banks in the region. There is little known about how climate change and ocean acidification will impact these communities or the larger ecosystem.
Scientists have documented that nearshore waters in the California Current system already have a low carbonate saturation state linked to coastal upwelling processes. Seasonal upwelling brings deep water, enriched in carbon dioxide, closer to the surface and near the coast.
It is anticipated that continued carbon dioxide research at Gray's Reef will help forecast how the benthic community will adapt as the Atlantic Ocean changes due to anthropogenic pressures. Researchers are currently investigating several aspects of climate change and ocean acidification effects on biological, chemical, and physical processes at Gray’s Reef National Marine Sanctuary.
Monterey Bay National Marine Sanctuary is the second largest national marine sanctuary and among the larger marine protected areas in the United States. Global climate change is increasing sea surface temperatures – this increasing temperature combined with increasing concentrations of atmospheric carbon dioxide are causing the world’s ocean to increase in acidity.
Regional physical changes in the north-central California coast and ocean include sea level rise, coastal erosion and flooding, and changes in precipitation and land runoff, ocean-atmosphere circulation, and ocean water properties.
Climate change may be a threat to the preservation of the USS Monitor wreck. An increase in temperature or change in seawater pH in the case of ocean acidification has the potential to accelerate or advance the deterioration of the wreck itself.
Global and regional changes to the marine environment associated with climate change may have significant consequences for coral reef ecosystems and coastal communities relevant to the National Marine Sanctuary of American Samoa.
Climate change poses a threat to all coral reef ecosystems throughout the world, and the Papahānaumokuākea Marine National Monument is no exception. The increase in average global temperatures, sea-level rise and increasing acidity in the world’s ocean are typically cited as the results of global climate change.
