The Geoduck: Mysterious, Controversial and Delicious

Most folks who visit the tidelands of coastal Washington encounter crabs, seagulls and other denizens common to any other beach in the United States. However, those who dig deep enough are likely to come face-to-face with a geoduck, the largest burrowing clam on Earth. Native American populations have hunted geoducks for centuries and scientists have long studied the creature’s fascinating biological traits. In recent years, however, the curious bivalve has been at the forefront of a passionate debate between environmentalists and shellfish farmers in the Pacific Northwest.

Pronounced ‘gooey duck’, the animal takes its name from gweduc, a term coined by the Nisqually tribe that translates to ‘dig deep’. The bivalves are native to the chilly coastal waters of Washington, Oregon, Alaska and British Columbia, though similar species have been found in more tropical climates.

Unlike clams, oysters and other members of the bivalve family, geoducks are equipped with a sizable appendage – a thick, rubbery ‘neck’ that the animal uses as a siphon to collect plankton, its main food source. The appendage may measure more than a meter in length, which means adult geoducks can weigh up to 14 pounds. According to Smithsonian Magazine, geoducks can live longer than 150 years. Their longevity is so notable that their necks develop rings much like those found in tree trunks, and scientists have used these markings to measure the effects of climate change.

And yes, people eat them. The geoduck is not only edible, but also rather tasty – and as a result, the creature is revered as a culinary delicacy around the world. This is especially true in East Asia, where geoducks often end up stewed in Chinese hot pots or diced up and served as sashimi in Japan. The animal is currently enjoying 15 minutes of fame among the American cooking elite, thanks to appearances on several popular TV shows including Anthony Bourdain: No Reservations, Bizarre Foods America and Top Chef Canada. And naturally, geoduck is a staple of the Puget Sound food scene, where ‘geoduck ceviche’ is all the rage these days. Those who have eaten geoduck attest to a savory combination of chicken and clam (with a refreshing, briny aftertaste), while Bizarre Foods host Andrew Zimmern described the animals as ‘ocean candy’.

Of course, in order to be served in a restaurant, the geoduck must first be unearthed – and this is no easy task, since the animal can bury itself more up to four feet beneath the substrate. Much like digging for clams, geoducks require quick action once the tide goes out. Locating the ‘neck’ is usually simple enough – it distinctively protrudes out of the sand like an extra-terrestrial periscope. But when the geoduck becomes frightened, it retracts the appendage below the surface (contrary to a widespread myth that the animal actually burrows deeper to evade predators).

According to the Washington Department of Fish & Wildlife, digging for geoducks is a “rite of passage for Washingtonians” akin to climbing Mount Rainier. And because the activity is so laborious, geoducks fetch a handsome market value; The Seattle Times says the clams usually go for roughly $25 per pound at the local dock, while Chinese vendors will sell them for as much as $150 per pound.

The clip below (from a 2006 episode of Dirty Jobs) illustrates a typical day in the life of a geoduck farmer.

The first geoduck fishery opened in 1970, when very few people outside the Pacific Northwest knew the animal existed. Geoduck farming began in the early 90’s, and commercial growing operations began sprouting up (pun intended) a few years later. Today, economists estimate that geoduck farming produces $80 million every year – but local environmental groups are worried about this burgeoning industry’s long-term environmental impact.

Laura Hendricks is chair of the Sierra Club’s Marine Ecosystem Campaign in Washington State. She says the biggest environmental threat related to geoduck farming concerns the widespread practice of placing the animals in tubes rendered from polyvinyl chloride (PVC) plastic until they reach maturity. These tubes act as protective barriers against the bivalve’s natural predators (which include birds, otters, crabs, large fish species and sea stars) during their vulnerable early stages. Ms. Hendricks noted that installation of these tubes in harvest areas – which may contain as many as 100,000 geoducks per acre – is permanently altering the marine ecosystem through the “conversion and displacement” of native plant and animal species. “They’re eliminating biodiversity and creating monoculture,” she said, adding that PVC materials have also been linked to human health risks.

Ms. Hendricks said the local food chain is another concern. Geoducks mainly subsist on a diet of phytoplankton, but environmentalists worry that farmed geoducks will also snack on certain types of zooplankton, such as the larvae of forage fish. These larvae are also a dietary source for large fish and marine mammals. If forage fish larvae are no longer in abundance, then native species like Chinook salmon will eventually be forced to alter their migratory patterns.

However, the shellfish industry disagrees. During a July 2012 meeting facilitated by the State of Washington Shoreline Hearings Board, a representative from Longbranch Shellfish LLC presented findings that contradicted both of these claims. During deliberations, the board found “no evidence that farmed geoduck will cause adverse impacts to forage fish or salmon by depleting food resources”, citing an earlier study that indicated geoduck subsist “exclusively on phytoplankton”. The board also supported the Longbranch rep with regard to the risks of PVC tubes, stating that the individual presented “a more detailed and convincing expert report”. Though the board ultimately ruled in favor of the shellfish company, one member issued a letter of dissent in support of the claims put forth by the environmental groups.

Bill Dewey is the Director of Public Policy and Communications for Taylor Shellfish Farms, the state’s largest shellfish supplier. He argues that shellfish farming operations in Washington adhere to legislation introduced in 2007 by State Rep. Patricia Lantz [D-Gig Habor], which established a set of rules related to commercial geoduck agriculture that have been implemented by local shoreline master programs. The legislation also allocated roughly $2 million to Washington Sea Grant (WSG), a federally funded academic research program that is administered by the National Oceanic and Atmospheric Association (NOAA). Mr. Dewey said that “excellent scientific research” conducted by WSG has supported the notion that geoduck agriculture is a sustainable industry. “We’ve got areas that we farm in three-crop cycles, so it’s roughly a six-year crop,” he said. “We are anecdotally not seeing changes in the beach. These are areas that are just as healthy as any other beaches we farm, and I think the research bears that out.”

In addition, Mr. Dewey says that geoduck farming has evolved over the last two decades to incorporate eco-friendly practices, including organized beach clean-up efforts that have yielded more than 100 dump truck loads of debris. He said that his company (and several others) now use a large, singular tarp to cover the geoduck harvest areas, rather than individual covers for each tube; this measure not only reduces the number of small plastic parts that are used, but also prevents tubes from blowing out to sea or across the beach if they are dislodged by wind. Some companies have also reduced noise pollution by replacing loud Honda engines with quieter pump models outfitted with decibel gauges.

Mr. Dewey said that Washington shellfish farms supply roughly 1.2 million pounds of geoduck per year, while fisheries yield roughly 4 million pounds of the bivalve. Despite the heavy volume, he argued that geoduck farmers are still failing to meet global demands for the product.

The questionable sustainability of geoduck agriculture continues to be an issue for Washingtonians. In August 2012, The Tacoma News Tribune reported that Pierce County officials revised the Shoreline Master Program to ensure that shellfish companies incur “no net loss of shoreline ecological functions”. The shellfish companies complained that the revised regulations were too restrictive on their business operations. Local residents, on the other hand, complained the new policies were insufficient.

By Brad Nehring