Lab-grown baby oysters, shipments of empty shells and muddy boots: Those are some of the ingredients that have made restoring the Olympia oyster successful in Fidalgo Bay.
Where overharvesting and water pollution in the 1900s left few, if any, Olympia oysters — a species once as integral to West Coast ecosystems as Pacific salmon and Dungeness crab — in the local bay there are now an estimated 4.5 acres populated by the native shellfish.
Since the estimated number of the oysters climbed into the millions in 2015, the population has remained strong. There are now an estimated three million of them in Fidalgo Bay waters.
“We pretty much hit a point where it looks like things are self sustaining,” said project lead Paul Dinnel, who is a retired marine scientist. “In general it has been very good with natural recruitment in the last half dozen years or so.”
That means oysters put in the bay through the project have successfully produced young, and those young have found new homes on shell, rock and other hard surfaces.
In some places, project partners — including the Puget Sound Restoration Fund and Skagit Marine Resources Committee — coaxed those baby oysters to take hold. Most recently, the partners dispersed empty Pacific oyster shells over about an acre of the bay’s muddy bottom in 2018.
In other places the oysters have made their own way with the help of tides and gulls. Tides can carry young oysters to new areas and gulls can drop empty shells that serve as new real estate.
Dinnel said during a recent online talk hosted by the Padilla Bay Foundation that there’s now interest in expanding restoration of the native oyster to other local waters.
“This might be a prime area for getting some Olympia oysters out in Padilla Bay,” Dinnel said as he showed a photo of channels slicing through the mud flats of the southern portion of the bay at low tide.
To find out for sure, Dinnel and Padilla Bay National Estuarine Research Reserve staff need to traverse the channels by kayak and muddy more boots. They need to determine whether there’s suitable Olympia oyster habitat.
“We were on tap for getting out there this summer ... but then COVID-19 hit and plans kind of went awry as field work was put on hold,” Dinnel said. “So that’s still on tap for the future.”
For now, the estimated 4.5 acres where Olympia oysters are believed to be thriving in Fidalgo Bay is a drop in the bucket compared to estimates of what the species once inhabited — 2,000 acres in Padilla Bay and another 2,000 acres in neighboring Samish Bay.
“That’s a lot where there are basically none now,” Dinnel said.
The Fidalgo Bay project has offered hope that the oyster can reclaim a place in these bays.
The project has also delivered some surprises, including Olympia oysters showing up in unexpected pockets of south Fidalgo Bay. That area wasn’t expected to be conducive to the oysters and is a ways from the primary restoration hub around the Tommy Thompson Trail trestle.
“Those oysters had to come from a spawning up around the trestle area,” Dinnel said. “There are some settling out in a lot of different areas, just not in very high densities.”
When the first oysters were delivered to Fidalgo Bay in 2002, it was the first project of its kind in north Puget Sound.
“We had our fingers crossed that they would survive and grow, because we had no really no idea what would happen,” Dinnel said.
The project’s success has helped spur additional ones in the region and is now one of about 40 along the West Coast, from Drayton Harbor in Whatcom County to Newport Bay in California, according to the Native Olympia Oyster Collaborative.
Baby oysters, called seed, used at the Drayton Harbor site, as well as projects in Similk and Skagit bays within the Swinomish Indian Tribal Community reservation, came from Fidalgo Bay’s established Olympia oysters, according to project documents.
According to a 2019 Skagit Marine Resources Committee report on the project, Fidalgo Bay oysters have also helped populate projects in San Juan, Jefferson and Clallam counties.
“There are many instances of Fidalgo Bay oysters being used ... to produce seed for other priority restoration areas in North Puget Sound,” Puget Sound Restoration Fund Executive Director Betsy Peabody said. “As oysters have increased in numbers in Fidalgo Bay itself, so have the number of restoration and research partners. The Fidalgo Bay effort has been really exemplary in that regard.”
The local partnership and its success was also highlighted in a 2019 book called “Goods and Services of Marine Bivalves,” an analysis of the economic and environmental roles of shellfish throughout the world.
The section about the Fidalgo Bay project said it was notable for “enabling the production of hatchery seed” that “helped Olympia oyster restoration efforts spread to many other locations across Puget Sound and the state.”
Taylor Shellfish Farms, which raises Olympia oysters commercially, provided the first oysters — fondly called baby Olys by some — that were left to their own devices in Fidalgo Bay.
Olympia oysters are the only oyster native to the West Coast and have historically played important roles in water quality and food webs.
Those working to bring the species back to Skagit County say the next major sign of success could be years away — the slow rebuilding of oyster reef habitat that’s long been a missing piece of the local ecosystem.
“You get some settlement of oysters and other oysters will settle on top of those oysters and you get, slowly, a buildup (of shell) over time,” Dinnel said. “This complexity creates hiding places for all kinds of critters ... including Dungeness crab.”
Dinnel said oyster reef habitat also supports other wildlife, including economically valuable seafood species.
Oysters themselves also help clean the water, each filtering up to 50 gallons a day, absorbing algae and nutrients that to them are food but left floating can harm water quality.