By Sean Nealon
Nearing retirement, Chris Langdon is focused on passing on the oyster breeding program he built and nurtured the past 25 years at Oregon State University. He is also looking to the future where two serious threats loom over the industry.
“Even though Oregon is a fairly small producer of oysters, OSU has made a huge contribution to the oyster industry,” said Langdon, a professor in the College of Agricultural Sciences, based at the college’s Coastal Oregon Marine Experiment Station at the Hatfield Marine Science Center in Newport.
“First, OSU was instrumental in the development of oyster hatchery technology in the 1970s and early 80s. And secondly, OSU’s breeding program has improved the performance of oysters and selected oyster stocks that are going to be more resistant to future threats.”
Ocean acidification and an oyster herpes virus threaten oyster farmers worldwide, including the West Coast of the United States. These threats are important reasons why the breeding program, previously led by Langdon, and now overseen by the U.S. Department of Agriculture Agricultural Research Service, recently received federal money to expand oyster genetics and breeding research at the Hatfield Marine Science Center. The threats are also a significant reason why OSU’s College of Agricultural Sciences is seeking state funds to continue to support aquaculture research.
Ocean acidification is a process by which oceans become acidified as larger and larger amounts of atmospheric carbon dioxide from burning fossil fuels dissolve in seawater. Once in the ocean, carbon dioxide forms carbonic acid, which lowers the seawater’s pH level, making it more acidic. This is bad news for oysters, whose shell-forming process is adversely affected by increasingly acidified waters.
Highly pathogenic strains of the oyster herpes virus, known as Ostreid Herpesvirus-1 or OsHV-1, have already decimated oyster farms in France, Australia and New Zealand. It’s only due to oyster breeding programs like Langdon’s that farmers in these countries have recovered with the development of oysters resistant to the virus.
Until relatively recently, the threats posed by OsHV-1 have seemed largely distant. However, in 2018, a strain of the virus was detected in San Diego, California, causing oyster farmers in the Pacific Northwest to fear its possible spread to local waters. Since then, they’ve turned to Langdon to develop virus-resistant oysters for their region.
Alan Barton, manager of the Whiskey Creek Shellfish Hatchery on Netarts Bay near Tillamook on Oregon Coast, is among those closely following Langdon’s research. His hatchery supplies oyster larvae to dozens of oyster farms on the West Coast and abroad.
“Our needs change and Chris has always been very able to adapt and tailor research to industry’s needs, like working on the herpes virus,’ Barton said. “It isn’t here yet, but when it is Chris is already going to have herpes-resistant families on hand.”
Pioneering a New Approach to an Ancient Industry
Langdon’s work builds upon a long history of oyster cultivation and research in Oregon. Oysters were an important food source for Native American and early European settlers. In the mid-1800s, native oysters were shipped to California to feed miners during the gold rush with returning ships bringing materials and supplies to Oregon’s isolated coastal communities.
In fact, the origins of Oregon State’s Hatfield Marine Science Center can be traced to the oyster. In the late 1930s, the Yaquina Bay Fisheries Laboratory was established in Newport, with a focus on water quality, estuarine ecology and oyster and clam aquaculture.
This laboratory served as the early precursor to the Hatfield Marine Science Center, which was built in the mid-1960s. Oyster research picked up there in the 1970s and 80s with a focus on oyster hatchery technology.
The next major step in oyster research at Oregon State occurred in 1996 when Langdon started the oyster breeding program, known as the Molluscan Broodstock Program, to improve survival, growth and yields of oysters. At the time, many were skeptical it could be successful.
“The whole idea of a breeding program to improve oysters was kind of foreign to the industry,” said Bill Dewey, director of public affairs at Taylor Shellfish, which is based in Washington and is the largest producer of farmed shellfish in the United States. “Chris really had to prove himself with that program and develop ways to communicate with the industry that the breeding program could lead to improvements for them.”
Langdon himself wasn’t sure what was possible.
“We were initially thinking that nature may have already done its best and we may not be able to improve on that,” he said. “We had colleagues and industry members who said we’re wasting our time. We did have ups and downs. In any breeding program you’re going to have situations in which you take one step forward and two steps back. But we have shown that breeding oysters works and that’s really gratifying to see.”
According to recent data from Langdon, oyster families in the breeding program showed average yields 87% greater than those of wild oyster families. Growth and survival rates also improved, with a 55% increase in growth and a 24% increase in survival.
Those improvements translate to financial gains for oyster farmers who use the seed from the Molluscan Broodstock Program’s selected broodstock, Langdon said. He estimates that farmers on the West Coast harvest oysters valued at $80 million annually. If all the farmers used seed derived from selected broodstock from the Molluscan Broodstock Program, he estimates a potential $48 million annual increase in harvest value.
Addressing the Symptoms, Not the Cause
About 10 years after Langdon started the oyster breeding program, the impact of ocean acidification became clear. It was 2007 and oyster larvae started dying at high rates at West Coast hatcheries, including the Whiskey Creek Shellfish Hatchery.
The hatchery sits next to Netarts Bay, where intake pipes pump saltwater from the bay to the hatchery. The water is then treated and pumped to tanks up to 20,000 gallons where the oyster larvae are grown.
In 2007, Barton, now manager of the hatchery, was working with the Molluscan Broodstock Program at Oregon State. He was dispatched to Whiskey Creek to figure out why the larvae were dying.
Ocean acidification and an oyster herpes virus threaten oyster farmers worldwide, including the West Coast of the United States.
Initially he and others thought it was a biological issue, such as bacteria. But after seemingly countless experiments, Barton realized that wasn’t the case. That led him to Burke Hales, an Oregon State professor and expert on ocean acidification and later George Waldbusser, another Oregon State professor. Research by Hales, Waldbusser, Barton and others confirmed the larvae were dying because the baywater was too acidified for the early larvae to form the shells they needed to survive.
Hales went on to develop a monitoring device, now known as the Burkolator. Through a series of sensors routed through a computer, the Burkolator measures parameters of the carbonate chemistry of seawater that affect larval shell formation. Barton and shellfish hatchery managers around the country now use the Burkolator to determine the degree of seawater buffering needed to protect their oyster larvae against the adverse effects of ocean acidification.
While the Burkolator is a great help for oyster farmers, ocean acidification is still real and remains a significant challenge. Though it currently helps oyster farmers make critical decisions to protect oyster larvae from its impacts, Barton and others remain concerned about what the future might hold.
Sitting around a table at the hatchery, wearing knee-high rubber boots, jeans and a hoodie, Barton recalled a recent conversation with Hales. Hales said that the chemical signature of the ocean water currently being driven to the surface in the Pacific Northwest, through a process called upwelling, dates back 40 years—a time when carbon dioxide emissions were well below what they are today.
“It’s clear the ocean will increasingly get more acidified every day of my career and whoever comes after me,” Barton said. “We’re talking 40 years minimally and that’s if everyone stops burning fossil fuels tomorrow.”
That virus is so deadly with Pacific oysters.
It’s 100% mortality in a matter of weeks
and it spreads rapidly.
It’s put the fear of God in growers on the West Coast here.
The Powerful Partnership of Science and Industry
On top of persistent concerns about the impact of ocean acidification, Barton, Dewey and other oyster farmers now have the added worry of OsHV-1.
“That virus is so deadly with Pacific oysters,” Dewey said. “It’s 100% mortality in a matter of weeks and it spreads rapidly. It’s put the fear of God in growers on the West Coast here.”
In recent years, Langdon’s breeding program has focused on developing oysters that are resistant to the virus. Members of his lab, led by Konstantin Divilov, have identified a genetic marker associated with resistance to the virus. Using that information, they have improved the survival rates of oysters exposed to a less pathogenic variant of the virus found in Tomales Bay, California, by about 35%.
Five years ago, in response to the herpes virus and ocean acidification, Langdon, working with the Pacific Coast Shellfish Growers Association and others, began seeking additional federal funding for the breeding program to help ensure its long-term future.
“The industry was at a crisis point with ocean acidification and the threat of OsHV-1,” said Dewey, who is also active with the Shellfish Growers Association. “The industry really felt that the genetics program was critical.”
It made sense for the association to work with Langdon and Oregon State to seek the funding because of OSU’s long history with oyster research, Dewey said. In preparation for an interview, he jotted down a page of notes of things OSU has done for our industry over the years.
“It’s extensive,” he said. “It’s probably more than any of the universities on the West Coast to be perfectly honest.”
In 2019, Langdon, the association and others were successful in securing substantial additional funding for the USDA Agricultural Research Service to continue the breeding program, known as the Pacific Shellfish Program, at the Hatfield Marine Science Center.
As Langdon winds down his career, the breeding program has now been transferred to scientists with USDA’s Pacific Shellfish Program, Neil Thompson and Bernarda Calla, with the anticipated addition of a third scientist soon. They will join Langdon at the Hatfield Marine Science Center.
Sitting in his office, on a sideways-rain morning in late fall, Langdon spoke optimistically about the future of oyster research at Oregon State.
Excited that modern molecular and genetic techniques are now being used to select oysters and happy that the transition of the breeding program has gone smoothly, he reflected upon the future of the program.
“When I passed it on, I said, ‘OK, it’s your baby now. I’ve nursed it long enough.”
He’s also enthusiastic about Oregon State’s effort to secure state funding for three aquaculture positions, one of which would continue Oregon State’s focus on oysters and other mollusks after Langdon retires.
No matter what the future holds, or who is leading oyster research at Hatfield, it is clear that the indelible partnership between science and industry will continue to find solutions to whatever new challenge presents itself.