Working to keep oysters healthy

Langdon’s research focuses on the aquaculture of oysters, genetic selection of oysters in order to improve all aspects of oyster production, and ocean acidification and hypoxia and its effects on oyster production. In simplified terms, he breeds and raises healthy oyster babies.

Langdon has been at Hatfield since 1986, where he started working on the nutrition of oysters. “It’s because I like it so much, I’ve stayed,” he said. 

The history of the oyster industry is long. Prized for their taste and alleged aphrodisiac qualities, they have been a delicacy for thousands of years.

In the mid to late 1800s, Yaquina Bay was abundant with native, or Olympia oysters, and they were big business. They were harvested, shipped and traded for goods to San Francisco. “It became a sort of gold rush to grow oysters,” Langdon said. Towns, like Oysterville and Oyster City were established along the Yaquina River. Unfortunately, it wasn’t long before the oysters were over-harvested and the area was fished out. As the oysters disappeared, so did those towns.

The Pacific oyster from Japan was introduced into Yaquina Bay about 100 years ago. Though they grew well, they could not spawn in the cold water of the bay. So each year, growers would import more oyster seeds from Japan. After a break in imports due to World War II, imports started again after the war, but the cost skyrocketed, and farmers sought out alternative sources.

In 1968, local scientists and philanthropists built three insulated rooms at the Hatfield Marine Science Center and began research into the feasibility of hatching Pacific oysters locally. That research, which has evolved into other areas, is a key to a healthy and sustainable oyster industry.

Langdon said that although the native oyster thrives in our local waters, there are several issues that make them less desirable than the Pacific oyster. “The seed of the native oysters stay on the mother and don’t get washed out in the water column like other oysters, so it is more difficult to produce large quantities of the larvae,” Langdon said. “A female may produce about 10,000 eggs, which is not enough to sustain them. They’re better adapted, but the growth is very slow and they are very small.” 

Pacific oysters grow quite fast, are very large and can be strip spawned. They can spawn 100 million eggs — a third of their body weight. “Hatcheries produce billions of larvae each year,” said Langdon. “You can’t produce that much native oyster larvae.” The hatcheries will sell either larvae that are almost ready to set or baby oysters attached to a surface, which are called spat.

Hatfield doesn’t deal with huge quantities of seed — just over 1,000. “We improve those and mate them with each other. We improve the genetics and give them to the farmers to grow and sell. It’s a win/win situation.”

It isn’t just Pacific oysters grown at Hatfield. They also breed the Kumamoto oyster, a highly desired oyster for connoisseurs, and a new stock of Pacific oysters from southern Japan called Midori oysters. Looking to the future, these stocks might do better than existing stocks and be more adapted to future warming. “We have a quarantine facility, so we can bring them in from Japan and to reduce pathogens,” said Langdon. “Each take about two years with rigorous testing. Breeding oysters is risky.” 

Scientists noticed a critical problem in 2006 when it was discovered oysters were producing about 50 percent less larvae than they had been. “It turned out we were seeing the early effects of ocean acidification. The water that was coming up to the coast from upswelling and plankton blooms due to warming global water.”

Betsy Johnson, a former Oregon state senator, realized what a serious problem it was and got some state funding and a grant to keep the research going during that critical period of time. “OSU has some of the best scientists in the world. We developed an electronic water monitoring system where the acidified water coming into the hatcheries is monitored, then the hatchery can automatically add a buffer to raise the pH and overcome the acidification of the water,” Langdon said. Most of the hatcheries globally now use this system and it’s been a major help for the west coast oyster industry.

“We’d been selecting oysters that are more resistant to ocean acidification in our hatchery. We had a lot of mortality but the survivors came through and it turned out that the larvae from our stock were more resistant than in the wild,” he said.

Eventually, the USDA department of Agriculture Research Service (ARS) took on the breeding project at Hatfield. Breeding programs are expensive and they have the ability to invest long term and with a considerable amount of money. 

Then in 2018, a devastating oyster disease, Ostreid herpesvirus type 1 (OsHV-1) was discovered, and it poses a major threat to the economy of the oyster aquaculture industry. It’s a virus that only affects the oyster — people cannot contract this virus from eating an oyster whether they are eaten raw or cooked. There hasn’t been a big outbreak of the virus on the West Coast yet, except for San Diego in 2020 when a high mortality of oyster seeds rang alarms. 

ARS hired two scientists to study disease resistance and develop a disease resistant stock, and Langdon is optimistic. “Luckily we can develop resistant stock to this disease,” he said. “Resistance is controlled by a fairly low number of genes so we can obtain resistance after about four or five years of breeding.”

Langdon is ready to pass the baton and plans to retire in a couple years. But the show, or research, will go on. “ARS and OSU will partner as collaborators in future research. Having this stable funding for oyster research is a huge step forward and will serve us well into the future.”