West Coast oysters are under attack, according to a recent article in the Los Angeles Times. An outbreak of Vibrio tubiashii bacteria has been wiping out the mollusks during their vulnerable larval stage, decimating shellfish hatcheries that supply seed oysters to aquaculture farms from Canada to South America. The bacteria is so virulent that Oregon’s Whiskey Creek Shellfish Hatchery, the Pacific Coast’s second-largest supplier, has been unable to produce any significant amount of larvae or seed for the past eight months.
“It’s pretty scary,” Sue Cudd, owner of Whiskey Creek, told the Times. “We almost decided to close, and people panicked. I realized if I go out of business, I take a lot of people with me.” Shellfish growers passed the hat to help fund a $200,000 water treatment system to filter and kill the bacteria. Oregon’s governor has also approved a $95,000 grant to Whiskey Creek for treatment research.
A previous oyster larvae die-off in 1998 was attributed to bacteria spread by upwelling warm ocean waters caused by the weather pattern El Niño, but scientists note that ocean waters climbed to unseasonably warm temperatures in 2007, causing another die-off, without El Niño. “There was a fundamental heating of the ocean waters in 2007,” researcher Ralph Elston of AquaTechnics told the Seattle Times. Warm waters have also expanded low-oxygen dead zones off the West Coast that scientists say may be related to global warming.
Unless a way to reduce bacteria levels in ocean water is found soon, future stocks of West Coast oysters could be in jeopardy. Oysters take 18 months to four years to reach harvestable size.
“Appreciate your shellfish while you still can,” Robin Downey of the Pacific Coast Shellfish Growers Association told the Tillamook Headlight-Herald.
Scary. But you know, there’s no such thing as global warming — I know, because President Bush and the EPA told me so (after suppressing all evidence to the contrary).
Just a minor correction: unless there’s a thermal vent on the ocean floor, warm water does not “upwell.” The linked article referred to warm water “coming up the coast” — I take that to mean extending from warmer regions, not coming up from below, which is what upwelling is. Upwelling is an incredibly important part of the ecosystem on the West Coast: it brings colder, nutrient rich water up from below, moderating the air temperatures and providing food for a weath of oceanic life forms (and the people who like to eat them). El Nino is actually characterized by a reduction in upwelling as the “bulge” of warm water from the tropics traps the cold water farther below.
http://sealevel.jpl.nasa.gov/education/el-nino-skit.html
Thanks for the correction, Ruth! I’ll have to read up more on it. It is scary stuff.