SEATTLE - A new report has found that ocean acidification continues to threaten water quality and wildlife in the Puget Sound. According to the report, surveys revealed the waters from the Strait of Juan de Fuca to the Great Bend of the Hood Canal are corrosive during part of the year — a troubling sign for animals that may be unable to build the shells they need to survive when seawater becomes increasingly acidic.

Authored by the Puget Sound Ecosystem Monitoring Program, a scientific partnership among universities and government agencies, the report also noted the presence of unusual, harmful algae that can contaminate shellfish, as well as nutrients from human activities, both of which are potential water-quality problems.

“Ocean acidification is already directly threatening Puget Sound’s wildlife. It’s alarming,” said Miyoko Sakashita, oceans director at the Center for Biological Diversity. “We have to act quickly to stop ocean acidification from unraveling Washington’s ocean ecosystem.”

In January 2012, the state of Washington classified the entire Puget Sound as “waters of concern” because of ocean acidification’s threat to local shellfish and fish resources. Surveys in 2008, 2009, 2010 and 2011 all reported corrosive waters in the Puget Sound that were attributable, in part, to ocean acidification. This means that the waters have low pH, and they don’t have enough of the materials that many shellfish need to build their shells. Such conditions have been linked to oyster die-offs in the Pacific Northwest. Since 2006, shellfish hatcheries in Washington and Oregon have reported massive oyster production failures related to ocean acidification.

“Science is showing us that the Pacific Northwest’s coast, and all the ocean life it supports, is in trouble,” said Sakashita. “This study suggests Puget Sound may be an early warning system for the future of our oceans. To save coral reefs and shellfish, we need to cut carbon pollution.”

In 2009 the Center for Biological Diversity filed a lawsuit challenging Washington’s prior water-quality assessment for failing to declare coastal waters impaired by ocean acidification. As a result of a settlement of that lawsuit, the U.S. Environmental Protection Agency directed all states to consider ocean acidification as a threat to water quality under the Clean Water Act. The Center has also urged Washington to develop new water-quality standards aimed at detecting ocean acidification.

Each day the world’s oceans absorb 22 million tons of carbon dioxide from the atmosphere, most of which comes from burning fossil fuels and cutting down forests. CO2 reacts with seawater, causing it to become more acidic; as a result the oceans have become about 30 percent more acidic since preindustrial times. Ocean acidification strips seawater of the materials that marine animals — such as corals, plankton and shellfish — use to build their shells and skeletons, which can have repercussions up the entire marine food web. Earlier this year, the Center for Biological Diversity called on the EPA to develop a national plan to address ocean acidification.

For more information, please see EndangeredOceans.org.