Every day, thousands of pounds of geoducks extracted from the floor of Puget Sound get loaded onto airplanes and shipped across the world, where the delicacy commands a high price.

The prized clam wholesales for more than $10 a pound and retails for as much as $40 a pound in Japan and other Asian markets. “Puget Sound gold,” some call it.

As fisheries go, the harvesting is among some of the most environmentally benign. Wild-stock geoduck, as it’s called, gets virtually hand-harvested from the sea floor, forced out of the substrate by a diver holding an underwater pressure hose. Seafood Watch, which issues advisories on the ecological cost of commercially harvested fish, gives wild-stock geoduck a “best choice” rating.

At the same time, biologists and regulators say, the high price the giant-sized clam commands has led to increased poaching and illegal harvests that the state is hard-pressed to track and that is putting pressure on the resource.

Ed Volz, who oversees the special investigative unit in the state Department of Fish and Wildlife’s marine division, said geoduck prices are the highest he’s seen in his 30 years on the job. He also has evidence that poaching is on the rise — including in the quiet waters off of Vashon and Bainbridge islands, places rich in geoduck.

“I am personally hearing about and seeing a lot more illegal geoduck harvesting these days because of the high price,” he said.

Two weeks ago, Volz said, his office obtained a search warrant and recovered illegally harvested geoducks from a boat docked at Zittel’s Marina in Olympia. Some of those geoducks, he added, likely came from Vashon’s waters.

“I am very concerned about the resource. … I think we have some serious problems in the geoduck industry,” he added.

Bob Sizemore, a biologist and the lead scientist on geoducks for the Washington Department of Fish and Wildlife (WDFW), said he, too, is concerned that high prices are leading to what he called “a lot of incentive to go out and break the rules.”

“There are some bad actors out there,” he said.

Geoducks (pronounced “gooey-ducks”) are long-lived clams; the oldest are thought to be more than 160 years old. They’re also considered the world’s largest burrowing clam — weighing in, on average, at two pounds. (The largest in the region, harvested 10 years ago, weighed just over eight pounds.)

Geoducks are called “broadcast spawners,” meaning that females release their eggs (as many as 10 million per year) at the same time that males release their sperm. Once an egg is fertilized and becomes a larva, it floats in the water for three to five weeks before burrowing into the substrate — where it settles in and stays put for the rest of its life.

Because of their sedentary lifestyle, geoducks are easy to count — and the state, which began regulating the industry in 1970, says it has a good handle on the extent of their population. An estimated 90 million geoducks are thought to live in the fishable portions of the region, the bulk of them burrowed into the sand in South and Central Puget Sound and along Hood Canal.

Two state agencies — the Department of Natural Resources and WDFW — regulate the wild-stock geoduck harvest, DNR with an eye towards managing the nuts and bolts of the harvest and WDFW tracking the clam’s biological status and the ecological impacts of commercial harvests. Several Puget Sound-area tribes also co-manage the resource, based on a 1994 judicial ruling — called the Rafeedi decision for the U.S. District judge who presided over the case — that recognized the tribes’ historic treaty rights to harvest shellfish in Puget Sound.

These days, state and tribal sources say, the industry is carefully regulated and co-managed — in part because the state was required to undertake an environmental impact statement that assessed the condition of the species, its habitat and the ecological impact of harvest practices. It’s the only fishery in the state governed by an EIS, Palzer said. Currently, a geoduck harvest tract — 16 exist around Vashon — is open to commercial fishing only after biologists have conducted surveys determining the extent of the geoduck population. Population levels, Palzer said, are not allowed to dip below 20 percent of what he calls the “pre-fishing biomass.”

“As part of this EIS, we do eelgrass surveys on every single tract that we fish. We establish buffer zones for them, and they’re protected. We definitely recognized the importance of the nearshore environment,” Palzer said.

In an era of declining state resources, the fishery is also a boon to the state, which receives an estimated $22 million a year from commercial harvesters — money that helps to fund, among other things, nearshore habitat restoration projects. State proceeds have climbed significantly in the last few years, Sizemore said — from $4 to $5 per clam to $10.

Tribes also benefit, charging its harvesters a geoduck clam fishery tax that is enabling it to purchase shoreline property in the region, including 11 acres on Vashon two years ago.

But Volz said he worries that the state is failing to stay on top of a poaching situation that he believes is growing worse. Vashon, he added, is one of the areas of concern — a place easier to poach than some because of the many quiet stretches of shoreline where illegal harvesters can park their boat. “We have some current investigations going on in your area,” he said.

Volz is well-known for both his success in nailing some high-profile geoduck poachers and his frustration with the state’s inability to do more to protect its fisheries. He figures prominently in Seattle journalist Craig Welch’s new book “Shell Games: Rogues, Smugglers, and the Hunt for Nature’s Bounty,” an acclaimed account of the black market surrounding geoduck and other wildlife.

Now close to retirement, Volz said he believes the state should do more to protect the giant-sized clam, an often laughed-at icon of the Puget Sound region and yet also a valuable and vulnerable resource.

His enforcement resources are few: He has only four officers and a sergeant to oversee all the fishery stocks in Central and South Puget Sound, he said. And in the case of geoduck poaching, it happens underwater and often at night, making enforcement particularly difficult.

“Honestly — and this is my opinion — we do not protect our geoduck,” he said. “Our job is to ensure that the rules are enforced. Our problem is that there are so very, very few of us.”

Islanders who suspect poaching should call the WDFW dispatch line at 360-902-2936. Or reach Washington State Patrol dispatchers by calling 911.