Country's largest estuary facing increasing acidification risk

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Chesapeake Bay, the largest estuary in the United States and one of the largest in the world, is facing new risks from a layer of highly acidified water some 10 to 15 meters below the surface, a new study has found.

This “pH minimum zone” is 10 times more acidic than the bay’s surface waters and may pose a risk to a variety of economically and ecologically important marine species, including oysters, crabs and fish, the researchers say. A decline in the number of calcium carbonate-shelled organisms – particularly oysters – may be hampering the bay’s ability to deal with the increase in acidity, they add.

Chesapeake Bay, the largest estuary in the United States and one of the largest in the world, is facing new risks from a layer of highly acidified water some 10 to 15 meters below the surface, a new study has found.

This “pH minimum zone” is 10 times more acidic than the bay’s surface waters and may pose a risk to a variety of economically and ecologically important marine species, including oysters, crabs and fish, the researchers say. A decline in the number of calcium carbonate-shelled organisms – particularly oysters – may be hampering the bay’s ability to deal with the increase in acidity, they add.

Results of the study are being reported this week in Nature Communications.

“Oysters and other bivalves provide a built-in Tums effect that naturally helps the bay deal with corrosive water,” said George Waldbusser, an Oregon State University marine ecologist and co-author on the study. “They generate large amounts of calcium carbonate structures, which may be able to buffer the increasing amounts of carbon dioxide entering the bay.

“Overharvesting and disease have reduced the number of oysters, however, and we’re seeing the results.”

Continue reading at Oregon State University

"Chesapeake Bay" by PA1 Pete Milnes is licensed under CC BY-SA 2.0