Ocean’s Rising Acidification Dissolves Shellfish That Coastal Tribes Depend On

“The tribes of the west coast of the U.S. are literally on the front line of ocean acidification impacts,” he said. “Oyster growers from Washington and Oregon have documented year after year of lost crops as tiny oyster larvae die from low pH water. What is going on in the ecosystem adjacent to Quinault? What other small organisms are being impacted, and how is our ecosystem reacting? We have a responsibility to know so we can plan for an uncertain future.”

Scientists from NOAA and Oregon State University studied ocean waters off California, Oregon and Washington shorelines in August 2011, and found the first evidence that increasing acidity was dissolving the shells of a key species of minuscule floating snails called pterapods that lie at the base of the food chain.

Their study, published in the April 4, 2014, edition of the British scientific journal Proceedings of the Royal Society B, found that 53 percent of pterapods “are already dissolving,” said NOAA’s Feely.

“Pteropods are only a canary in this coal mine,” the Quinault’s Schumacker said. “They are a critical component of salmon diets, but what other creatures in the ecosystem are being affected?”

It’s a concern too, for the Yurok Tribe on the northern California coast. Micah Gibson, director of the Yurok Tribe Environmental Program, told ICTMN, “We’ve done some research, but no monitoring yet.”

The Passamaquoddy Tribal Environmental Department in Maine is monitoring ocean acidification, according to a letter the tribe sent to the U.S. Environmental Protection Agency (EPA). They reported that the pH of Passamaquoddy, Cobscook Bays and the Bay of Fundy was around 8.03 during the 1990s and had dropped to 7.92.

The lower the pH value, the more acidic the environment. If, or when, the Passamaquoddy letter stated, the level in bays falls to 7.90, shellfish—including clams, scallops and lobster, all economic mainstays—will die.

In Alaska, coastal waters are particularly vulnerable because colder water absorbs more carbon dioxide, and the Arctic’s unique ocean circulation patterns bring naturally acidic deep ocean waters to the surface, according to recent research funded by National Oceanic and Atmospheric Administration (NOAA) awaiting publication in the journal Progress in Oceanography.

Ocean acidification spells even more trouble for the Inuit subsistence way of life.

“New NOAA-led research shows that subsistence fisheries vital to Native Alaskans and America’s commercial fisheries are at-risk from ocean acidification,” NOAA said in the report. “Emerging because the sea is absorbing increasing amounts of carbon dioxide, ocean acidification is driving fundamental chemical changes in the coastal waters of Alaska’s vulnerable southeast and southwest communities.”

The pH of the ocean’s surface waters had held stable at 8.2 for more than 600,000 years, but in the last two centuries the global average pH of the surface ocean has decreased by 0.11, dropping to 8.1. That may not sound like a lot, but as of now the oceans are 30 percent more acidic than they were at the start of the Industrial Revolution 250 years ago, according to NOAA.
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