DISCOVERY BAY — A project to restore dwindling native Olympia oyster populations has shifted from planting oyster seeds to monitoring what remains of the silver-dollar-size mollusks nearly wiped out by overharvesting, pollution and loss of habitat during the past two centuries.
“We think there is only about 4 percent of the original habitat that still exists,” said Joth Davis, Port Townsend Marine Science Center and county Marine Resource Committee consulting shellfish biologist who works for Taylor Shellfish Co. on Hood Canal.
“We believe we can bump up the populations with appropriate techniques. We hope that we can bring back the oysters in the places where they were.”
The Olympic oyster project, which Jefferson County’s Marine Resource Committee has coordinated through state dollars over the past seven years, was infused with a $32,000 two-year grant from the state Department of Ecology, which the county commissioners approved last week.
The grant allows the county’s volunteer Marine Resources Committee to contract with Port Townsend Marine Science Center and shellfish researchers to monitor remnants of the original Olympia oyster populations in a tideland pocket on Discovery Bay.
The grant also includes East Dabob Bay, Seal Rock near Brinnon and Triton Cove at the county’s south end.
Hundreds of thousands of oyster seeds, or spat, were planted on the beaches at the head of Discovery Bay since 2002, but those close to the project determined that a new direction was necessary — monitoring existing native Olympic Oyster habitat to find a model that could be replicated in ideal habitat locations around the region.
The group has this year focused research on a “small but robust” Discovery Bay lagoon pocket discovered while planting seeds and uncovered in 2008 when an old sawmill was removed.
The Marine Resource Committee’s latest report this year states that the clearing of vegetation and creosote-coated wood and wood waste from the former mill site appears to have had no effect on the population discovered there that includes healthy spawning adults.
Michael Adams, Marine Resource Committee chairman and a commercial shellfish grower on Bywater Bay near Port Ludlow, said the Discovery Bay project focuses on 349 Olympia oysters in various stages of growth. While some oyster mortality has been observed there, he said the general population is strong.
Healthy population
“We found that East Jefferson County has a healthy population of Olympia oysters and if conditions are right they can actually thrive,” Adams said.
The Olympia oyster grows best in a thin layer of water and its larvae adheres to hard surfaces such as rocks.
Adams said it is illegal to harvest oysters less than 2.5 inches long and the Olympia oyster is smaller than that, which helps protect it.
While the Olympia is Washington state’s only native oyster, its sparse populations range from Southeast Alaska to Baja California, Mexico.
Oysters typically harvested on the North Olympic Peninsula’s private, recreational and commercial shorelines, especially along Hood Canal, are the much larger Pacific oysters, native to Japan.
The Olympia oyster was an important food source for Native American coastal tribes and early British explorers described Discovery Bay’s tidelands as being blanketed with Olympia oysters.
Overharvesting significantly depleted oyster stocks in Puget Sound by 1870, with ship loads of the tasty Olympia oysters feeding gold miners during the mid-1800s in San Francisco, according to historic accounts.
Unregulated effluent from surrounding pulp and paper mills before the 1950s also played a large part in Olympia oyster declines.
To augment disappearing and ailing stocks, oyster harvesters began importing the larger and faster-growing Pacific oyster in large numbers, which soon replaced the Olympia oyster in cultivated beds.
Adams said the Discovery Bay location was chosen as a focus of future Olympia oyster study because it has easy access and is a controlled site that can be studied over time.
Discovery Bay natives Olympia oysters under study are also not believed to be inbred with other commercial stocks, Adams said.
“It’s more of a monitoring project than a restoration project,” said Adams, who volunteers as a county marine shoreline steward.
Davis said the Discovery Bay project in 2008 appeared to be “a virtual disaster, with poor water quality, and the oysters looked terrible.
“We thought it was one more little population that was going to bite the bullet, but in 2009 we had a banner year. So some years are good, some years are not so good.”
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Port Townsend-Jefferson County Editor Jeff Chew can be reached at 360-385-2335 or at jeff.chew@peninsuladailynews.com.