Pacific Coast Shellfish Industry is Canary in Coal Mine
Shellfish producers in the Pacific Northwest are the first harbingers of a trend that may have wide ranging implications for the fishing industry: ocean acidification. They also embody the phrase, “a stitch in time saves nine.” By proactively seeking out adaptation solutions early on, the shellfish industry is performing a self-rescue and it’s showing signs of working.
The general acidity of the oceans has risen 30% 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.
The Pacific Coast of North America is being hit particularly hard because, due to a unique system of wind and currents, deep water surfaces 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 on 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. Eventually they had 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 in to Netarts Bay had unusually low pH levels. The implications were monumental and treatment options only theoretical. Sue said, “I was in despair. The problem was so big.” The ramifications were big indeed. Whiskey Creek produces 75% of all oyster seedlings used by West Coast oyster farmers.
Washington State shellfish growers tell a similar tale. Iconic Willapa Bay oysters haven’t reproduced on their own 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 shipped back to Willapa Bay once they are old enough to withstand the acidity.
Although the West Coast of North America is ground zero, other coastal areas including Maine and Virginia are also seeing rapid changes in ocean chemistry.
The harm done to oyster farmers is just the tip of the iceberg. Kathleen Nisbet stated, “It hit us first but it’s just going to expand to other industries.” Acidification could in fact disrupt the entire marine food web. For example, pteropods, tiny, snail-like creatures, are a fundamental food source for myriad species and make up 50 percent of the diet of some salmon stocks. Researchers had predicted pteropods could begin dissolving by mid-century, but Seattle scientists have recently discovered that acidifying seas are already damaging pteropods— decades earlier than expected.
Realizing the urgency, some states are beginning to take action. In 2011, former Washington Governor Christine Gregoire commissioned a ground-breaking Blue Ribbon Panel on Ocean Acidification. The panel identified 18 key early actions as essential in our effort to address ocean acidification.
The most urgent action is to slow the pace of acidification by reducing global carbon dioxide emissions. If carbon emissions continue to rise at current rates, Researchers estimate ocean acidity may double or triple by the end of this century, compared to pre-industrial levels.3 Resulting pH levels would likely be lower, and the rate of change 10 times faster, than anything the oceans have experienced in 20 million years.
Importantly, panel scientists found that in addition to carbon emissions, local sources of pollution, such as wastewater and polluted runoff containing nitrates, exacerbate acidification. Panel co-chair Jay Manning noted, “We need to develop a better understanding of the magnitude of these sources, and if they prove to be significant, act immediately to reduce loading from local sources.”
Oregon and California are forming a joint scientific panel to gain a clearer understanding of the effects of acidification in those jurisdictions. All three coastal states and British Columbia are developing a collaborative approach to addressing this pressing issue.
These are important first steps. Scientists can monitor ocean chemistry and work with industry, local communities and governments to identify and address the worst problems resulting from ocean acidity. In addition, adaptation strategies are essential, especially expanding monitoring capacity. With its state-of-the-art monitoring system Whiskey Creek is now able to shutdown intake when acidity levels are dangerously high. Wiegardt says installing the monitoring system was like, “Turning on the headlights.”
Shellfish farmers are the canaries in the coal mine. By closely following their proactive and successful quest for solutions, all fishing industry sectors will stand a better chance of overcoming the great challenge of this century.
1. Washington State Blue Ribbon Panel on Ocean Acidification (2012): Ocean Acidification: From Knowledge to Action, Washington State’s Strategic Response. H. Adelsman and L. Whitely Binder (eds). Washington Department of Ecology, Olympia, Washington. Publication no. 12-01-015.
2. The Royal Society, 2005 and Ridgwell and Schmidt, “Past constraints on the vulnerability of marine calcifiers to massive carbon dioxide release,” doi:10.1038/ngeo755, Feb. 14, 2010, Nature Geoscience, published online: 14 february 2010, http://pages-142.unibe.ch/science/scor/ gfx/Ridgwell&Schmidt2010NGeo-PastOceanAcidification.pdf.