Group Threatens Suit Related to Ocean Acidification

The Center for Biological Diversity notified the U.S. Environmental Protection Agency of its intent to file a lawsuit against the agency for failing to respond to the threat of ocean acidification.

Last year, the center filed a formal petition asking EPA to impose stricter pH standards for ocean water quality and publish guidance to help states protect U.S. waters from ocean acidification. The notice of intent to sue urges EPA to promptly respond to the center's petition.

The oceans cover about 70 percent of the Earth's surface and absorb about 22 million tons of carbon dioxide each day. The absorption of carbon dioxide is changing seawater chemistry, causing it to become more acidic. This process, known as ocean acidification, impairs the ability of marine animals to build the protective shells and skeletons they need to survive.

Already, the pH level of the ocean has decreased 0.1 units on average due to carbon dioxide pollution caused by human activity – especially emissions from such sources as automobiles and electrical power plants, according to the press release from the center. If carbon dioxide emissions continue unabated, seawater pH may decrease an additional 0.4 units — more than a 100 percent change in acidity. A recent article in the journal Science noted that rapid changes in pH would have adverse effects on a number of marine organisms ["Carbon Emissions and Acidification"]. "The seawater quality criteria of the U.S. Environmental Protection Agency date back to 1976 … [t]hese standards must be re-evaluated based on the latest research on pH effects on marine organisms," the authors wrote.

The federal Clean Water Act requires the EPA to update water-quality criteria to reflect the latest scientific knowledge. Since the agency developed the pH standard back in 1976, an extensive body of research has developed on the impacts of carbon dioxide on the oceans.

"Ocean acidification is global warming's evil twin," said Miyoko Sakashita, an attorney with the Center for Biological Diversity's oceans program. "The EPA has a duty under the Clean Water Act to protect our nation's waters from pollution, and today, carbon dioxide is one of the biggest threats to our ocean waters."

If EPA strengthens the pH water-quality criterion for oceans, then the Clean Water Act requires states to adopt a water-quality standard at least as protective as the one established by the agency. Here, stronger water-quality standards for pH could translate into measures that regulate pollutants such as carbon dioxide, which is causing ocean acidification.