Keywords: Species and food webs, Invertebrates, Nearshore habitat, Salish Sea, Bivalves, Shellfish, Implementation Strategies, Tribes

The geoduck has earned an honored place as Puget Sound's largest and most distinctive native clam, but how much do we really know about it? Often seen as a culinary curiosity, the geoduck has only been commercially harvested on a large scale since the 1970s, and the clam's current popularity is based mostly on demand from Asian markets. Nevertheless, this deep-burrowing mollusk has always been a signature part of the Salish Sea ecosystem. 


Puget Sound’s residents have harvested geoducks for thousands of years. Or at least that’s the theory. The huge, meaty mollusks would have surely been a good food source. All one had to do was dig a hole in the beach at low tide to find a clam that could provide several pounds of nourishment. With up to 8-inch-long shells and a siphon that can extend three feet, geoducks are the largest burrowing clams in the world. And, some of the longest lived, with one collected in Puget Sound that was 173 years old. Those who relish geoducks barbeque them, put them in chowder or a hot pot, or eat them raw, in sushi. One local chef described the taste as “sweet as it gets for something that comes from the ocean.”

Pacific geoduck clam (Panopea generosa). Photo: Don McCullough (CC BY-NC 2.0)

Pacific geoduck clam (Panopea generosa). Photo: Don McCullough (CC BY-NC 2.0)

Unfortunately, we have no evidence that the early residents ate geoduck. No shells appear in the archaeological record — perhaps because geoduck shells disintegrate easily and are therefore hard to distinguish from other shelled critters. They may not have ended up in middens, too, because they were processed on beaches at low tide and would have washed away. Yet, the very name geoduck, variously spelled gwiduc, goeduck, gooeyduck, and gweduck, comes from the Lushootseed word gwidəq, meaning "dig deep," so clearly the great clams were well known, and probably eaten.

Remarkably, one of the first appearances in print of the word geoduck comes from the February 23, 1883, New York Times, where an unnamed writer described them as the “prince of clams.” The Times reporter had been influenced by malacologist Henry Hemphill, who had visited Puget Sound in 1881 and become smitten: Geoduck were the “most delicious of any bivalves I have ever eaten, not excepting the best oysters,” he wrote. Hemphill then proposed a complicated scheme to ship live geoduck to the east coast so that those less fortunate might enjoy the fabulous bivalve. Like all other similar plans to follow, it failed.

Although there was apparently only a limited local demand for what another early enthusiast, R.E.C. Stearns, called the “boss clam of North America,” Puget Sound residents thought the clams were being over-harvested. In response, in 1925, the state legislature banned catching, taking, or possessing a geoduck. Five years later, legislators were still concerned about too few geoducks but decided to reopen the tidelands and allow harvesting but only three per day and only for personal consumption; none could be sold or canned. To this day, the daily, three-duck-per-person rule applies.

For the next four decades, time and tide limited geoduck harvesters. The massive clams could only be dug out during very low tides, generally in the summer, when the water had retreated far enough to reveal the tip of the geoduck’s long siphon, or neck as some call it. Resembling a pig’s snout, the siphon is initially the only visible part of the clam; the main body and the shell sit two to three feet deep in the sediment. In order to feed, geoducks extend their muscular siphon into the water and filter feed on phytoplankton; waste expulsion occurs via a parallel channel in the siphon.

Low tide at Golden Gardens in Seattle reveals the siphon of a geoduck in a bed of eelgrass. Photo: Sylvia Kantor.

Low tide at Golden Gardens beach in Seattle reveals the siphon of a geoduck in a bed of eelgrass. Photo: Sylvia Kantor.

An unexpected discovery

Then in 1960, Robert Sheats and a team of Navy divers made an unexpected discovery while conducting their regular job of locating torpedoes lost on the bottom of Puget Sound. (The Navy began testing and servicing torpedoes at Keyport in 1914 and continues to do so to the present.) During one such dive deep in Hood Canal, they found geoducks living in habitat far below tide line. Up to this point, biologists thought that geoducks only lived intertidally (between high and low tide) and no deeper. After reporting his find to state biologists, Sheats worked with them to determine how many geoducks lived on the bottom of Puget Sound. Their initial total was 63 million individuals, which led to the state establishing its first ever commercial harvest.  

Despite the lack of a market, unregulated production went from 82,000 pounds in 1970 to 2.4 million in 1975 and ultimately to 8,708,000 in 1977, a quantity that has never been equaled.

The harvest began in May 1970 when Sheats and his wife Margaret dove to the sandy bottom of Thorndyke Bay on Hood Canal and pulled up fifty live clams. In the subsequent months, they harvested 4,021 geoducks, operating under the company name of Bubble Heads, Inc. The Sheats hoped to market the clams to local food markets and restaurants but found little success. Instead, they ended up setting up a stand on the side of the road and selling them there for about a dollar a pound, compared with the quarter per pound paid by restaurants. Bubble Heads’ partner Herman Kunz also tried canning the geoducks and met with even greater failure. Other companies, such as Washington King Clam, had much higher harvests, collecting more than 192,000 clams between 1970 and 1972 in Agate Pass (off the north end of Bainbridge Island), but they, too, failed to find a demand for the weighty clams. A 1972 report for the Department of Fisheries by economic consultant Lee E. Erickson concluded that “this is not a profitable business yet, but the potential does exist.” Despite the lack of a market, unregulated production went from 82,000 pounds in 1970 to 2.4 million in 1975 and ultimately to 8,708,000 in 1977, a quantity that has never been equaled.

Mesh bag of geoduck clams. Photo: David B. Williams

Live geoduck (average weight is 3-4 pounds) harvested in Agate Passage by divers working for Suquamish Seafood Enterprises. Photo: David B. Williams

A new market

As Craig Welch tells the story in "Shell Games: A True Story of Cops, Con Men, and the Smuggling of America’s Strangest Wildlife," the price did not rise until a market developed in Asia. He notes that geoduck became popular in China in part because dinner hosts often sought out the most exotic food they could find, and few foods featured the geoducks’ combination of taste, texture, and appearance. Welch tracks the story through a variety of geoduck sellers—one who ended up in jail for his illegal tactics, one who was a born huckster, and one who actually understood the Chinese desire for unusual foods—who took a dozen years or so to create a new overseas market. By 1994, the price of Washington state geoduck had risen above $4.00 per pound, after remaining below $.50/pound from 1970 to 1990. In 2013, sales from 6.2 million pounds of Washington geoduck was valued at $70.5 million, with at least 90 percent ending up in China. No other state produces a remotely comparable number of geoducks.

Wild stock harvesting, the practice pioneered by Robert Sheats, produces two thirds of the state’s marketable geoducks. Unlike most other marine species, such as herring or sea urchins, which one can gather over a broad region, geoduck harvests occur at a specific location with a specific harvest quantity. Akin to forestry, geoduck management begins when the Washington State Department of Natural Resources, which owns the bottomlands of Puget Sound, sends out divers to evaluate each tract, either virgin or previously harvested. For the latter, divers determine if enough geoducks have returned to make the harvest viable. On average, 40 to 50 years must pass before a second harvest can occur.

As with the salmon harvest, the harvest is split evenly between Tribal and non-Tribal entities. And, similar to what happened with salmon, a landmark case restored tribal rights. Following the logic of the 1974 Boldt Decision (often referred to as United States vs. State of Washington), Judge Edward Rafeedie decided on December 20, 1994 that the “usual and accustomed clause” applied to shellfish. Prior to the Rafeedie Decision, no tribes had a commercial shellfish program; now they harvest clams, oysters, crab, sea cucumbers, and shrimp.

All wild stock harvesting occurs in water between 18 and 70 feet. (Geoduck have been found in water as deep as 300 feet. In 2018, the state estimated that 487 million geoducks inhabited Puget Sound.) To reach the geoducks, divers travel by boat out to the geoduck tract, put on a full wet suit with weights, and dive to the bottom, always connected to the boat by an oxygen hose. On the bottom, the divers feel for geoduck siphons, then blast around them with a high-pressure hose, which loosens the geoducks and lets the diver pull them out easily. Once a diver has filled a net with 200 pounds or so, she or he sends those to surface. The geoducks will then be packed on ice, typically transported to Sea-Tac Airport, and flown to China, where they may go on sale the next day or remain in a large tank for several weeks.

Geoduck farmers take the remaining one third of the geoduck harvest. State biologists began developing the modern farming technique in 1987 not for aquaculture, but as a way to supplement wild track harvests. In the years after the state commercialized geoduck diving, the biologists worried that too many geoducks might be taken and that they should try to supplement the wild stocks. The biologists tried more than 100 experiments transplanting 18 million clams on recently harvested beds. They had no success for the first couple years. Predators kept eating the juveniles. Eventually, the biologists used plastic tubes to protect the edible youngsters, though it was impractical for restocking the wild beds.

A novel technique

The biologists, though, recognized that there was a commercial opportunity for geoducks and tried to interest shellfish growers in the novel technique by making presentations at annual meetings of scientists and industry. “There wasn’t a lot of interest at first…Most of the shellfish companies were busy producing clams and oysters. It wasn’t until my third talk or so that they got involved. Part of the problem was the time involved because they could harvest in two to three years whereas geoducks are more like five to ten,” says Hal Beattie, who managed the WDFW facility. The companies, though, eventually adopted the new technique.

Baby geoducks ready for planting. Photo: VIUDeepBay (CC BY 2.0)

Baby geoducks ready for planting. Photo: VIUDeepBay (CC BY 2.0)

Geoduck farming begins on a shallow-sloped beach with the partial burial of row upon row of 12-inch-tall by four-inch diameter, vertical plastic tubes at low tide. Divers next swim by at high tide and deposit four baby geoducks in each tube, which rises several inches above the subsurface. Because the youngsters are vulnerable to predation, the tubes receive a mesh cover. Six months or so later the geoducks are about the size of kumquat and big enough that the mesh cap can be removed. Workers then return a year later to remove the tubes; the lemon-sized clam has now buried itself away from predation. By the time the geoducks are ready to be harvested, after five to seven years of growth, they will weigh a couple pounds and be the size of a baked potato.

Ecological impacts

Not everyone supports commercial geoduck aquaculture. People typically complain about the aesthetics of the geoduck tubes and how they detract from homeowners’ pristine views. Shina Wysocki, owner of Chelsea Farms, responds that the tubes are only visible part of the day and that they tend to get coated in green algae in less than a year. More fundamentally, Shina says “It’s a working waterfront issue. We need to get people to see that the Sound is not just a view and to see it as a living ecosystem that people rely on for jobs and for food.”

Others who object to the farms, cite ecological, recreational, economic, political, and land-use issues, according to a 2017 University of Washington study based on interviews with state agency employees, representatives of the aquaculture industry, nongovernmental organizations, and landowners. Their concerns include plastic from the PVC tubes, how the nets change the dynamics of the beach, and that a monoculture is inherently lower quality than a natural ecosystem. They are further troubled by the possibilities of losing walking and boater access to beaches and reduced land values.

In contrast, two studies published in 2015 of south Puger Sound geoduck aquaculture by University of Washington scientists showed that geoduck aquaculture has minimal and temporary effects on the ecosystem and that overall biological diversity changes very little. The new, three-dimensional habitat formed by the tubes and nets benefits some fish and larger invertebrates and creates a refuge that discourages flatfish and predatory moon snails. The structures may also lead to a decrease in bald eagle abundance, according to the report, which could benefit migratory shore birds preyed upon by eagles.

Biologists have also examined mollusk aquaculture as it compares to fisheries, livestock, and fish aquaculture. University of Washington fisheries ecologist Ray Hilborn published the most exhaustive study in 2018. Hilborn and his team reviewed 148 cradle-to-grave assessments that addressed energy use, carbon footprint, nutrient release, and acidifying compounds and found that beef production and catfish aquaculture had the worst environmental impact production methods. The best were small pelagic fisheries (e.g. herring) and mollusk aquaculture.

Researchers acknowledge that the results from their short-term studies on relatively small plots may fail to reveal cumulative long-term effects on a single location or a mosaic of locations, so they are continuing their research. They also note though that intertidal organisms are adapted and resilient to disturbances because they evolved in an ever-changing environment characterized by waves, tidal fluctuations, shifting substrates, storms, flooding, and thermal stress.

One consistent area of concern for geoduck farming is the use of plastic tubes but even the Monterey Aquarium’s Seafood Watch program, which produces the most respected fisheries-related environmental reports, concluded the issue is “surrounded by uncertainty.” Regulations are in place requiring cleanup of lost tubes and studies have shown that PVC may be less prone to degrade or leach pollutants in the marine environment than on land. As one ecologist told me, geoduck farming “is not as bad as people claim nor as good as the farmers claim.”

Washington's geoduck auction

The geoduck harvest begins in Olympia at the state’s DNR offices with regularly scheduled public auctions of the harvest rights. At one auction attended by the author in February 2019, the bidders consisted of 15 companies representing American and Chinese interests. Prior to the auction, the companies had the opportunity to read an environmental assessment of the tracts, or Puget Sound bottom land available to be leased. Each assessment contained a detailed description of the property, including information on substrate, water quality, previous harvest history, digging difficulty, and geoduck density. The data came from Washington Department of Fish and Wildlife, whose divers had visited each tract and counted geoducks and other species, such as moon snails, horse clams, and Dungeness crabs. It was this data that led to a decision to open a tract or keep it closed until it had returned to a harvestable condition.

Geoduck auction bids, February 20, 2019. Photo: David B. Williams

A typical range of bids listed by company at a DNR geoduck auction, February 20, 2019. Photo: David B. Williams

The auction began precisely at 9:00 A.M. when Blain Reeves, the DNR assistant aquatic resources manager, announced the first tract. Bidders then dropped a white envelope in a box at the front of the room. Each envelope contained a bid and a $75,000 deposit check. After opening the box, Reeves pulled out each bid and announced the amount, which a staffer wrote down on a large piece of paper on an easel. Losers got their checks back and the winner got to fill out paperwork.

Each bidding round took about four minutes followed by 16 minutes of quiet chatter in English and Chinese between the bidders. Bidding continued through lunch, a catered meal provided by DNR.

Bids for the 17 tracts ranged from $5.00 to $11.78/pound, depending upon the tract quality, with the highest total bid $314,999 for two tracts, one west of Dungeness Spit and another north of Dash Point. The lowest was $122,700 for a tract south of Anderson Island. By the end of the day, the state had taken in $4,584,524. Auction winners then had 13 days to pay the remainder of their bid. In addition, they would also have to pay $4.00 per pound to the state for every pound they harvested, which would not be available to harvest until later in spring.

— David B. Williams


About the author: David B. Williams is a naturalist, author, and educator whose award-winning book Too High and Too Steep: Reshaping Seattle’s Topography explores the unprecedented engineering projects that shaped Seattle during the early part of the twentieth century. He is also the author of "Seattle Walks: Discovering History and Nature in the City," "The Street-Smart Naturalist: Field Notes from the City," and co-author of "Waterway: The Story of Seattle’s Locks and Ship Canal." This story is adapted from David’s next book - "Homewaters: Human and Natural History in Puget Sound." Williams is a curatorial associate at the Burke Museum and you can find him on Twitter at @geologywriter.

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