oysters.jpg

Seed Sale Coordinator Dave De Andre holds a handful of Pacific Diploid oysters at Taylor Shellfish near Shelton, Wash.

(The Associated Press)

The Natural Resources Defense Council released a report today that won't come as a surprise to Northwest shellfish growers.

Ocean acidification--a chemical imbalance in the water caused by carbon dioxide emissions--is hitting the Northwest harder than other parts of the country.

Authors of the report, "Vulnerability and adaptation of US shellfisheries

to ocean acidification," ranked Oregon and Washington high among regions expected to be rocked by the ocean's changing chemistry, but not only because of our water conditions. They picked us because many Northwesterners make their living off shellfish - a species that's particularly vulnerable to acidification.

"It's the first place that has seen measurable, attributable impacts from ocean acidification," said Sarah Cooley, a scientist with the Ocean Conservancy who co-authored the report.

Shellfish larvae rely upon calcium carbonate in the water to form their shells. Under normal conditions, the ocean is saturated with the chemical. But the huge amounts of carbon dioxide that have entered the ocean have neutralized much of the calcium carbonate and subsequently made it difficult for larvae to form shells.

Oregon and Washington mollusk fisheries produce more than $100 million in annual sales and employ thousands either directly or indirectly. Losing larvae means losing money, and can have a trickle down effect on the entire coastal economy.

Other factors play a role in our region's vulnerability, researchers found. Coastal areas such as the Puget Sound are polluted with nutrient runoff from farms, lawns and sewage systems, contributing to algal blooms that worsen acidification. The Columbia River and other waterways are poorly protected from erosion and pollution, making their water unusually acidic for fresh water. Upwellings lift acid water from the deep, depositing it onto the coastline.

"Upwelling is a normal phenomenon, but what is not normal is that the water it's scooping up has extra CO2 in it," Cooley said.

Marine scientists at NOAA's Newport outpost and other coastal research hubs have been working with the shellfish industry for several years on ways to protect shellfish larvae when waves of sour water pass by hatcheries.

Although other coastal communities haven't experienced immediate harm from souring oceans, Cooley said, "it doesn't mean they're off the hook." As greenhouse gases from our tailpipes, chimneys and factories continue to pollute the ocean, "people are starting to think about, 'How is this affecting our resources?'"

"It's something that's going to be constantly changing the baseline, constantly shifting what normal actually looks like," Cooley said. "With this study, we want to allow some precautionary thinking that will encourage people to think about what they're likely to experience, and start adapting. At the end of the day, we really still have to work on cutting carbon dioxide emissions."

-- Kelly House

khouse@oregonian.com

503-221-8178

@Kelly_M_House