Climate Science

two photos show a bleaching event that occurred over three months
Many people believe that climate change is a slow process, but these changes are actually rapidly affecting our ocean. These two photos show a bleaching event that occurred over just three months in National Marine Sanctuary of American Samoa. When corals are stressed by warmer water, they evict their colorful symbiotic algae, called zooxanthellae. But corals need these algae to help them get enough food, and once they've bleached, the corals may not survive. Photo: XL Catlin Seaview

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.

buoy in the water
The NOAA Pacific Marine Environmental Lab, the University of Georgia, and Gray's Reef National Marine Sanctuary have been monitoring the partial pressure of CO2 (pCO2 or the concentration of CO2 in seawater) offshore Georgia since 2006. Increase in seawater CO2 levels decreases the ocean's pH (also known as ocean acidification, or OA). That change in pH is monitored with high-resolution instrumentation attached to a buoy (shown here), and a separate instrumentation package deployed on the seafloor. Photo: NOAA

Learn more about climate science in the National Marine Sanctuary System:

American Samoa

Channel Islands

Cordell Bank

Florida Keys

Flower Garden Banks

Gray's Reef

Greater Farallones

Hawaiian Islands Humpback Whale


Monterey Bay

Olympic Coast

Papahānaumokuākea Marine National Monument

Stellwagen Bank

Thunder Bay

Wisonsin-Shipwreck Coast