Minimum size limits for clams on the Quilcene Bay tidelands have been increased, as a decline in the oyster population has allowed the clam population to flourish.

The Washington State Department of Fish and Wildlife (WDFW) issued a fishing-rule change March 22 that is to go into effect April 1 regarding the minimum size limit for Manila, native littleneck, cockle and butter clams harvested for personal use from public tidelands on the west side of Quilcene Bay north of the county boat ramp.

The new rule increases that minimum size limit from 1.25 inches to 1.5 inches, measured across the longest dimension of the shell.

This removes the exception to the statewide minimum size limit for clams at the Quilcene Bay tidelands. The rule’s smaller minimum size of 1.25 inches was in place because, historically, clams on the public tidelands in Quilcene Bay tended to be stunted, and did not often reach the standard minimum harvest size of 1.5 inches.

Camille Speck, speaking for the WDFW Port Townsend office, explained that changing ecology, likely related to “a decrease in oyster biomass” on the Quilcene Bay tidelands, has resulted in more normal growth patterns for Manila clams at this location.

“The oyster population is smaller now than it used to be in the aforementioned public tidelands,” Speck said. “I can’t speak for the private tidelands, but the public area covers a lot of that ground.”

Speck attributed the oyster numbers “going way down,” at least in part, to the cleanup of aquaculture sites in the area within the past decade or so.

“Removing that gear removed a lot of oysters in the process,” Speck said. “Between that and harvesting by sport and treaty fishermen, the clams have responded by growing more.”

As a result, state and tribal comanagers have agreed that the smaller minimum size restriction for clam harvests on the west side of Quilcene Bay, north of the boat ramp, is no longer necessary.

Speck compared the supply of plankton and other nutrients that are brought in by the tide to deliveries of groceries for the oysters and clams.

“It used to be that the oysters would grab more of those groceries before they reached the clams, that are higher up on the beach,” Speck said. “People shouldn’t be alarmed about the oysters, though. They’re still doing well enough that there’s plenty of them for treaty and sport fishermen.”

This change in the minimum legal size applies to both state and treaty fisheries.