Olympia Oysters Making a Comeback in Sequim Bay

Thumb-sized baby Olympia oysters have been spotted on the Sequim Bay tidelands where Jamestown S’Klallam tribal members and staff tossed Pacific oyster shells last summer.

“We spread these shells in an area that looked good for Olympias after a tribal picnic to add to the shoreline habitat since oysters need shells to survive,” said Ralph Riccio, Jamestown’s shellfish biologist. “This is amazing because now there’s a bunch of baby Olympia oysters growing in this little area.”

Riccio’s observation is a testament to Sequim Bay’s role as a poster child for the resurgence of Olympia oysters. The small oysters are native to the Northwest but have declined to dangerously low population levels.

The nonprofit Northwest Straits Commission (NWSC) aims to restore 100 acres of tidelands for Olympias by 2020. The tribe collaborated with the Clallam County Marine Resources Committee which received funding from NWSC.

In 2013, the tribe spread 200 bags of seeded oyster shells, known as cultch, on an acre of Sequim Bay tidelands, followed by another 100 bags on the same area plus another half acre in 2014.

In 2015, the tribe put out non-seeded cultch to create more habitat and support natural recruitment, providing substrate for naturally produced spat (shellfish seed) to settle on.

The three years of work have paid off.

“The recruitment levels of oysters have been good,” Riccio said. Within the 1.5-acre restoration site, “it is hard to find shells that have not been colonized by Olympias.”

Olympia oysters are not highly regarded in the commercial market, Riccio said, but they are native to the region, and tribes have been harvesting them for millennia.

“As filter feeders, they provide a service to the ecosystem,” Riccio said. “Bringing back a native species could have other ecological benefits that we don’t know about. They may be subtle benefits, but they could be important to the overall marine environment.”