The gradual increase of acid in the oceans threatens coastal communities in 15 states, although the reason for the impact – and what to do about it – varies widely, according to a new study.
Writing in the journal Nature Climate Change, a group of researchers declared ocean acidification “a complex and seemingly overwhelming problem.” That’s partly because of its varied nature, and partly because of big gaps in what is known about it.
States are at risk, according to the study, because of straight economic factors – the size of their seafood industry, for example – as well as their “adaptive capacity,” which the authors said is how adaptable states are to change and how prepared governments and economies are for it.
“It’s not just the threat of the changing chemistry,” said Chris Langdon, a professor in the Department of Marine Biology and Ecology at the University of Miami who participated in the study. “It’s whether the people – the society – are geared up to do anything about it.”
It’s why states such as Washington, which reacted swiftly when ocean acidification damaged its oyster industry, might be economically vulnerable but don’t rank high on the authors’ “social vulnerability” scale.
And it’s why states along the Gulf of Mexico do rank high. They have communities dependent on shellfish for economic survival but governments that haven’t done much to counteract acidification, according to Lisa Suatoni, a senior scientist at the Natural Resources Defense Council.
“If you are an oyster farmer in St. Bernard Parish, La., you may need to be worried about ocean acidification,” said Suatoni, one of the authors of the report. “There are pockets of vulnerable communities that have not gotten the attention they deserve.”
Such places have “low adaptive capacity because they have governments that haven’t done anything about it,” she said.
Ocean acidification is sometimes referred to as “the other carbon dioxide problem,” and it’s exactly what the name implies: the gradual increase of acid in the world’s waters. It’s fueled by the burning of fossil fuels and the massive amounts of carbon that releases. A good chunk of that is absorbed by the world’s oceans, making the water more acidic.
Additional acid makes it hard for some species to develop the shells they need to survive, which has instilled fear in government and fisheries leaders around the country.
In Washington state and the Pacific Northwest, the issue hit home between 2005 and 2009, when acidified conditions killed billions of oyster larvae at two of the main hatcheries that provide Pacific oysters to growers. Hatcheries scrambled to boost the monitoring of ocean chemistry and to adapt growing methods to avoid particularly acidic waters.
More recently, leaders in Maine convened a state commission to understand the problem and detail ways to counteract it.
The study in the Nature Climate Change journal concluded that ocean acidification is a long-term, global problem and that reducing carbon dioxide in the world’s waters “will take decades to accomplish successfully.” Until that happens, local areas will need to undertake measures to adapt to and mitigate the problem.
The study was conducted by researchers from the Natural Resources Defense Council, an environmental advocacy group; the federal government; and academic centers such as Duke University and the University of Miami.
The study divided the nation’s coastal waters into regions and found that 10 out of 23 are exposed to two or more threats of acidification. The marine ecosystems around the Pacific Northwest and southern Alaska are expected to be exposed soonest to ocean acidification, followed by other parts of the West Coast and the Gulf of Maine in the northeast.
Beyond that are pockets along the East Coast and the Gulf of Mexico, where the study found that acidification will come earlier than generally expected because of local stressors such as algae blooms caused by pollution runoff.
While parts of the Pacific Northwest and the Northeast are projected to hit a key acidification threshold in the next decade or so, other parts of the country aren’t projected to hit it until the second half of this century, although local factors make those projections difficult to nail down.
Among the hot zones the study identified:
– In New England, Maine and southern Massachusetts have poorly buffered rivers that run into the cold New England waters that already have high levels of carbon dioxide.
– In Mid-Atlantic areas such as the Chesapeake Bay, abundant nitrogen pollution exacerbates ocean acidification in shellfish-rich areas.
– In the Pacific Northwest, Oregon and Washington coasts and estuaries have several risk factors, including cold waters, upwelling that brings corrosive waters closer to the surface, and nutrient pollution from land runoff.
Overall, the study found that communities in 15 states are most at risk for economic impact from ocean acidification. The states, in order of risk, are: Massachusetts, New Jersey, Virginia, Washington, Oregon, Connecticut, New York, Rhode Island, Maine, Florida, North Carolina, California, Louisiana, Maryland and Texas.