Pacific Northwest shellfish producers are the first harbingers of a trend that may have wide ranging implications for the broader fishing industry: ocean acidification. By proactively seeking out adaptation solutions early on, the Northwest shellfish industry is attempting a self-rescue that may provide important lessons as other commercial species begin feeling the impacts of increasing acidification.
The general acidity of the oceans has risen 30 percent since the Industrial Revolution.1 The culprit is carbon, which is being released into the atmosphere through the burning of fossil fuels such as coal and oil. The oceans act like massive sponges soaking up airborne carbon. As carbon dissolves in seawater it forms carbonic acid, which lowers pH and increases acidity. This carbonic acid takes on a corrosive quality, eroding sea animal shells or skeletons, as well as robbing the water of important nutrients that allow these animals to grow shells in the first place. 2
The Pacific Coast of North America is being hit particularly hard because, due to a unique system of wind and currents, deep water rises to the surface along the West Coast. This older water has been absorbing carbon for a relatively long period of time and is therefore unusually acidic.
The West Coast shellfish industry, which contributes more than 100 million dollars a year to the economy and provides thousands of jobs, is in jeopardy. Acidity levels are already high enough to prevent oyster larvae from forming shells.
Whiskey Creek Shellfish in Netarts Bay, Oregon, was one of the first to identify acidity as the cause of high mortality rates in larval oysters. Owners Sue Cudd and Mike Wiegardt explain that the problem started in 2007. They experienced four straight months of zero production. Suspecting bacteria, they spent hundreds of thousands of dollars on treatment equipment, but it wasn’t effective.
Then hatchery manager Alan Barton, with a degree in oceanography, discovered the water coming into Netarts Bay had unusually low pH levels. The implications were monumental and treatment options only theoretical. “I was in despair. The problem was so big,” said Cudd. The ramifications were big indeed. Whiskey Creek produces 75 percent of all oyster seedlings used by West Coast oyster farmers.
Washington State shellfish growers tell a similar tale. Iconic Willapa Bay oysters haven’t self-reproduced since 2005. Every grower now relies on hatchery-produced larvae.
The Nisbets, of Goose Point Oysters, have been producing Willapa Bay oysters for nearly 40 years. When they realized the magnitude of the acidification problem they took drastic action, taking out a loan and building a new hatchery in Hawaii, where acidification is not yet a problem. The larvae are then shipped back to Willapa Bay once they are old enough to withstand the acidity.