Ocean Acidification Carbon dioxide emissions are making the water uninhabitable for shellfish

The Problem

Ocean acidification (OA) is the name for the process of the oceans becoming more acidic due to increased levels of carbon dioxide in the atmosphere. This change threatens ocean ecosystems, the food chain and the livelihood of coastal residents.

The acidic conditions created by CO2 emissions are harming fisheries, aquaculture farms, coastal recreation and diversity in the ocean. Animals like oysters and clams use a substance called calcium carbonate to build their shells. Acidic water erodes that calcium carbonate and makes the organisms fragile, much like osteoporosis in a human. Even worse, the acidity could completely eliminate animals like the pteropod—a type of sea snail—that serve as a key food source for small fish, which in turn feed commercial fish like salmon and tuna. Investing in long-term research will help determine specific impacts of OA and will lead to the development of effective management and mitigation tactics to preserve our economies and ecosystems.

Ocean Acidification

Fast Facts

As the ocean absorbs carbon dioxide, it reacts with water molecules to form carbonic acid, thereby increasing the overall acidity.

The oceans are acidifying at a rate 100 times faster than any time in the last 200,000 years, and perhaps all of Earth’s history, according to a 2012 study. 

The ocean absorbs 25-30 percent of carbon dioxide emissions from the atmosphere, roughly 22 million tons per day, according to NOAA.

Fishermen and the aquaculture industry will lose jobs and profits due to OA. A 2009 study found that mollusk—shelled animals like oysters—sales could drop between $75 and $187 million annually due to acidic ocean conditions.


  • In 2012, Washington State created the Blue Ribbon Panel to review OA research and issue recommendations. The Marine Resource Advisory Council was subsequently created to establish a coordinated response to OA and engage in public outreach. More information, including bill text, is available here.
  • Maine and Maryland task forces have completed reviews, and legislators in those states are now looking to implement recommendations. 
  • In 2016, California (AB.2139), New Hampshire (SB.375), New York (A.10264), and Rhode Island (H. 8223) enacted legislation to study the impacts ocean acidification on their states’ economies. California also enacted a bill to look at OA mitigation through a blue carbon program (SB.1363).  New Hampshire’s bill includes this provision as well.

Science and Reports

West Coast Ocean Acidification & Hypoxia Science Panel

This report highlights major findings and recommendations that can be taken now to address ocean acidification and hypoxia. The panel included stakeholders from British Columbia, California, Oregon and Washington.

Maryland Task Force to Study the Impact of Ocean Acidification

This report details the impact of ocean acidification on state waters and is directed at the Governor and State General Assembly.

Washington State Blue Ribbon Panel on Ocean Acidification 

This report outlines the impacts of ocean acidification on Washington State and provides recommendations for action. These recommendations later established the Washington Marine Resources Advisory Council.

Maine Commission to Study the Effects of Coastal and Ocean Acidification 

This commission, created by the state legislature, analyzed existing and potential effects on species that are commercially harvested and grown along the Maine coast.


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