Scientists Deposit 200,000 Rare Oysters in a Shipwreck 100 Feet Below the Surface of the North Sea

European flat oysters have nearly disappeared from the region. Now, researchers are helping them recover by depositing the oyster larvae on gravel beds off the coast of Belgium

Sarah Kuta | Daily Correspondent

July 29, 2025

Share

Copy linkEmailSMSFacebookXRedditLinkedInBlueskyPrint

Add as preferred source

European flat oysters were once abundant in the North Sea. But because of human activities over the past century, they’ve largely disappeared.

Now, scientists have come up with an innovative plan to help the mollusks rebound—and restore vital marine ecosystems in the process. In early July, researchers deposited 200,000 European flat oyster (Ostrea edulis) larvae into the hull of a shipwreck off the coast of Belgium, reports Agence France-Presse (AFP).

Flat oysters are often referred to as “ecosystem engineers” because they build reefs, which provide shelter and protection for various marine animals. They also perform other important functions, such as water purification, nitrogen fixation and seabed protection.

Only 30,000 of the 200,000 larvae are expected to survive the first year. However, the project’s organizers are hopeful those oysters will start reproducing to create a self-sustaining reef.

“Our ambition is to create long-term nature restoration, without further human intervention,” says Vicky Stratigaki, an engineer and the Belreefs project coordinator at Jan De Nul Group, a construction and offshore energy company based in Belgium, in a statement.

Scientists, government officials and industry partners have spent the past two years working on the pilot project, which is called Belreefs. It’s been supported with funding from the Belgian government, as well as the European Union.

The shipwreck—a cargo vessel called Kilmore that sank in 1906—is resting on the seafloor roughly 20 miles from Ostend, a coastal city in northwest Belgium. Scientists say the wreck is the perfect location for the project because it’s closed to fishing and other potentially disruptive activities. The vessel, submerged 100 feet below the surface, is also located atop gravel beds that historically hosted oyster reefs.

“In Belgium, every wreck that is … more than 100 years on the sea bottom gets protected automatically as cultural heritage, because it’s nice for divers to go there,” says Merel Oeyen, a marine environment policy advisor with the Belgian health ministry, to AFP. “It’s also a hot spot for biodiversity.”

Prior to the 1850s, flat oysters—and their reefs—were common throughout European waters. But the creatures began to disappear in the late 19th century because of overfishing and other activities that disrupted the sea floor. Their demise was later hastened by a parasite called Bonamia ostreae, which is thought to have been imported from California around 1979. The lethal invader killed off nearly all of the remaining flat oysters in France, the Netherlands and Belgium.

Now, conservationists are taking steps to restore Europe’s flat oyster populations and their reefs. It won’t be easy, but the organizations partnering on Belreefs are optimistic about the project.

Now that the larvae are in place, organizers plan to conduct extensive monitoring for several years to understand how and where the oysters affect the marine ecosystem. If the pilot project is successful, officials hope to expand the efforts to other parts of the North Sea and beyond.

“The North Sea is not only a key economic engine, but also a unique natural environment that we must safeguard,” says Annelies Verlinden, Belgium’s minister of justice, in a statement. “Deploying young oysters is an investment in biodiversity and climate resilience. Projects like Belreefs help us achieve our goal to restore at least 20 percent of our North Sea ecologically by 2030.”

Sarah Kuta | Read More

Sarah Kuta is a writer and editor based in Longmont, Colorado. She covers history, science, travel, food and beverage, sustainability, economics and other topics.