The Marine Resource Committees for Clallam and Jefferson counties will use federal funding to replenish strata in Sequim Bay and Discovery Bay to help rejuvenate Olympia oyster populations depleted by the “heat dome” in September 2022.
The shells will be placed on tidelands located at Jamestown S’Klallam Tribal Tidelands on about 2 acres of current restoration area and 1 acre of new restoration area to expand the Olympia oyster population in Sequim Bay.
“We figured this was a great project that we could get done in one year,” Clallam County Habitat Biologist Rebecca Mahan told Clallam County commissioners at their Jan. 9 work session. “So we are going to be bringing in some substrate to add to the Sequim Bay area in hopes that we get more improvement on the Olympia oysters. They did take a big hit during that heat dome.”
Clallam County will receive $96,650 in Congressionally directed spending, formerly called earmarks, through the Northwest Straits Commission via the National Oceanic and Atmospheric Administration.
Jefferson County will receive $118,000 for its oyster restoration project that started in 2013 with one-half acre in Discovery Bay near a stable but small population of Olympia oysters and now consists of three parcels. Volunteers spread empty shells on a quarter acre of nearby tide flats in August 2014.
“Olympia oysters (Ostrea lurida) are ecosystem engineers, forming complex carpets of overlapping shell that provides hiding places and feeding opportunities for a diverse community of nearshore species,” according to the Jefferson County Marine Resource Committee website.
Larvae released from the nearby population settled on those shells in 2015 and 2016. Additional shells were added to the project site in 2016 to replace the shells that the currents and wave action had moved southward. Empty oyster shells were added to a new area nearby in 2019 and in ensuing years.
The Clallam County project will place 200 cubic yards of shells in locations known to be successful for recruitment or ideal habitat, according to a staff memo to county commissioners. The shell placement plan will be based upon six years of population assessments, a three-year recruitment study that illustrates spatially how Olympia oysters have recruited outside of the three existing restoration sites and local knowledge of the site.
The data will be used to determine where shells will be added outside the three current restoration sites. Empty shells will be transferred onto a landing craft and positioned at predetermined GPS locations. The shell bags will be placed at high tide so they can be accessed at low tide for spreading by hand. Then the area will be monitored to see if the project works.
Mahan said any oyster shells can be used, but these will be Olympia oyster shells harvested from along Hood Canal and trucked to the areas to be shoveled into the water.
Mahan said baby oysters need some place to adhere in order to grow, and oyster shells are the best substrate.
“And Sequim Bay, as we know, has seen lots of human-led changes over the centuries,” Mahan said. “And so, it’s just kind of bringing back that substrate that was there.
“And then trying to figure out, “Where do these guys want to settle? We have a couple new spots,” she said.
Clallam County Commissioner Mark Ozias said: “This sounds like an interesting project and one that, later on in the year when we have our annual (Marine Resources Committee) update, I’m looking forward to hearing a little bit more about it.”
“It sounds like a fun research project to do afterwards,” Clallam County Commissioner Mike French said.
“It will be great to look at the recruitment over time and see if it actually works,” Mahan said.
The Olympia oyster is the only native oyster from British Columbia to Baja California. Due to habitat loss and overharvesting, their populations are a fraction of what they once were prior to the arrival of settlers in the mid-1800s.
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Reporter Brian Gawley can be reached at brian.gawley@soundpublishing.com.
