Since the beginning of the industrial revolution, the global ocean has absorbed a third of the carbon dioxide emissions from fossil fuels, transforming it into carbonic acid. The acidity of the marine environment has increased by roughly a third since 1750, changing chemical processes vital to life, including shell and coral formation and the growth of bony structures in fish. This massive change in ocean chemistry is a growing water quality problem that focuses attention on the surprisingly difficult business of determining whether and how a particular water quality standard has been violated. Such attention brings with it a larger question of whether water quality criteria are legally sufficient under the CWA if they are difficult or impossible to test as a practical matter, and highlights the changing role of the act as it is used to combat a new class of water pollution.

The world's oceans are absorbing carbon dioxide at an unprecedented rate and the resulting acidification is transforming marine ecosystems. Hari Sreenivasan reports on how ocean acidification is already affecting oysters and other shellfish in the U.S.

Since the beginning of the industrial era, humans have pumped increasing amounts of carbon dioxide into the atmosphere. This has led not only to a warmer climate but also to significant changes in the chemistry of the oceans, which have long acted as a sink for carbon emissions but are being asked to absorb more than they can handle. The result is ocean acidification: increasingly corrosive seawater that has already ruined many coral reefs and over time could threaten the entire marine food chain.

This state can’t afford to wait for decisive action by federal and global leaders on the pressing problem of climate change. One of the most compelling cases in point is the growing evidence that ocean acidification is raising havoc with the marine ecosystem in the Pacific Northwest, including Puget Sound. Last week, a panel of scientists and policymakers appointed by Gov. Chris Gregoire issued a sweeping set of recommendations to combat ocean acidification.

EPIC environmental issues usually stir educated passions tugging in opposite directions. The alarming acidification of the world’s oceans is indisputable: It is all about chemistry.