By Mathew Roland
Shellfish farming in Washington is a multimillion-dollar industry with a history as deep as Puget Sound. However, recent decades of warming oceans and higher levels of ocean acidification continue to challenge shellfish farming practices.
In and around Whatcom County there are several aquaculture farms, such as Lummi Shellfish Hatchery, Drayton HarborOyster Co., Blau Oyster and Taylor Shellfish in Samish Bay. Each farm varies in size, number of employees and type of shellfish produced, but they share one thing in common: the water quality of Puget Sound.
There are more than 300 aquaculture farms across Washington, according to the Pacific Shellfish Institute. A WashingtonState Maritime Sector Economic Impact Study in 2017 found that the industry directly supports 15,900 jobs. Samish Bay shellfish farms alone include $2 million annual payroll and $6 million in wholesale oysters, clams and geoduck.
In June, four ocean acidification bills made bipartisan progress, in the U.S. House of Representatives and Senate, to becoming law. The bills are designed to encourage research and spur new ideas for adapting to the affects of ocean acidification. The bills include the COAST Research Act of 2019, the Coastal Communities Ocean Acidification Act of 2019,the Ocean Acidification Innovation Act of 2019 and the NEAR Act of 2019.
As carbon dioxide is emitted into the atmosphere a certain percentage is absorbed into the water, causing a chemical reaction that makes the water more acidic. According to the National Ocean and Atmospheric Administration, roughly 25%of carbon dioxide emissions are absorbed into the worlds oceans. The process is similar to bubbles escaping from a soda can, but in reverse. Since the industrial revolution ocean acidification has increased by 30% and reduced carbonate ions by16%, said Bill Dewey, director of public affairs for Taylor Shellfish. By the end of the century it is predicted that ocean acidification will increase by 100% to 150% and reduce carbonate ions by 50%, said Dewey.
The reduction in the availability of carbonate ions is not good for shellfish larvae, also referred to as seed. Carbonate ions are the building blocks for shellfish such as oysters, clams and mussels. Dr. Brook Love, assistant professor at HuxleyCollege of the Environment, has a Ph.D. in chemical oceanography from the University of Washington, and her research focuses on ocean acidification. “It takes more energy to build a shell when the water is acidic,” Love said. “Acidic water is more likely to dissolve the shell.”
Because of its location, Puget Sound gets north winds in the summer. These winds causes upwellings which bring carbon dioxide that was dissolved into the ocean decades ago to the surface and into the estuaries of Puget Sound.
It was thought to be upwelling that brought more acidic water into the Sound and decimated shellfish hatcheries in thePacific Northwest between 2008-09. Oyster farms were not being supplied with seed, and it became more difficult to collect oyster seed from the wild. The shortage hit the seafood industry hard.
“Ocean acidification has impacted us already. We are probably the first industry in the world to be impacted by it and know it,” Dewey said.
The seed shortage spurred a swift response from farmers and local government to take proactive measures that would lessen the effects of ocean acidification on shellfish agriculture in the future. The Ocean Acidification Blue Ribbon Panel was developed in 2012 by then-Gov. Christine Gregoire to bring together shellfish farmers, scientists and policy makers with the goal of better understanding and adapting to the consequences of ocean acidification.
Since then, shellfish farmers have collaborated with nonprofits, implemented new ways to monitor ocean chemistry and continued sustainable shellfish farming practices. Drayton Harbor Oyster Co., owned by Steve and Mark Seymour, relay their oysters to deeper water to combat warmer ocean temperatures, a common practice in the industry. The company is also working with the Puget Sound Restoration Fund to restore native Pacific Oyster habitat that will improve water filtration and support biodiversity.
For Taylor Shellfish, adapting to more acidic water meant looking for new places to grow that are a natural refuge from ocean acidification. There is potential for growing shellfish in or around large eel grass or kelp beds because eel grass and kelp pull carbon dioxide out of the water for photosynthesis, Dewey said. Taylor Shellfish is also investing in breeding programs to develop an oyster that is more resilient to acidic water.
The Lummi Hatchery uses large sand filters to process the water that feeds into the hatchery, and in the past few years they added a series of secondary filters to ensure that water quality meets the needs of the growing crop. Ralph Solomon, 68,has been an oyster farmer at the Lummi Shellfish Hatchery since 1989. While the Lummi hatchery was not heavily impactedby the 2008-09 seed crisis, it experienced a substantial loss of oyster seed in early summer of 2012 and 2015 that theywere not able to explain. Best guess was that something was wrong with the water quality, Solomon said.
“It’s an alarming story to raise attention to ocean acidification,” Dewey said. “But its also a positive story to say that if we allwork together and collaborate, besides needing to address the source of the problem, which is carbon pollution, there areways that we can adapt and mitigate and thats what we need to focus on.”