The quickly rising levels of carbon dioxide (CO2) in the atmosphere are leading to ocean acidification (OA), as the oceans absorb this excess CO2. Global ocean pH has declined by about 0.1 units since pre-industrial times, representing an increase in acidity of about 30 percent. The Mid-Atlantic may be especially vulnerable to acidification in coastal waters, where high nutrient levels and rapid growth of plankton further reduce pH. OA causes organisms to expend more energy to regulate their body chemistry and reduces the availability of calcium carbonate (CaCO3), which corals, clams, oysters, lobsters, and other species require to build and maintain shells and skeletons. As a result, OA could have important effects on numerous culturally and commercially important species in the region.

The Mid-Atlantic Coastal Acidification Network (MACAN) seeks to answer basic questions about the intensity, frequency, and location of acidification events. MACAN seeks to understand the causes of those events, whether from atmospheric sources of carbon, land based pollution, or something else. MACAN also works to educate managers, elected officials, industry representatives, and the public about solutions to reduce those sources of acidification. MACAN can be a starting point to work together towards data driven answers to tough acidification questions.   

News & Events


Webinar: Acidification Effects Upon the Atlantic Surfclam

 MACAN's Feb. 12 webinar explored how carbon dioxide levels affect the physiology and energy budget of surfclams


Civic Science Initiative: Oyster Project

Learn how CSI Oyster engages citizen scientists to study the link between oyster growth rates and water quality in Chesapeake Bay


NOAA, IOOS Fund Acidification Research

NOAA and the U.S. Integrated Ocean Observing System have jointly funded four projects aimed at improving the observing system design for characterizing ocean acidification


New MACAN Journal Articles

Through two working groups, MACAN has produced manuscripts for Estuarine, Coastal, and Shelf Science focused on research priorities for ecological impacts and acidification monitoring


MACAN in National Geographic

Article examines work to understand what ocean acidification will mean for East Coast


Where is Acidification Being Monitored?

Learn about our interactive maps on the Mid-Atlantic Ocean Data Portal

Click Icons to Learn About Acification's Effects On:

Cold-Water Corals

Cold-Water Corals











Submerged Aquatic Vegetation




NOTE TO USERS: Sharing information is an important role that MACAN plays in the region. However, any resources shared from members on this site does not indicate endorsement by the entities coordinating MACAN or those on its Steering Committee. 

Contact Us

If you would like to contact MACAN or join our listserv, email us at