Geoducks: Happy as Clams- page 4 | Science | Smithsonian
They may not be beautiful, but geoducks fetch a pretty price. (Natalie Fobes)

Geoducks: Happy as Clams

In the Pacific Northwest, fishermen are cashing in on the growing yen for geoducks, a funny-looking mollusk turned worldwide delicacy

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Goodwin, who has studied geoducks since 1967 and retired from the state wildlife agency in 1994, remains a clam fanatic. He named his sailboat Panope and his car license plate reads "GEODKR." In the early 1970s, Goodwin became the first person ever to breed geoducks in a laboratory setting—in a five-gallon bucket. "I just wanted to see if it could be done," Goodwin recalled. To study the mollusk's early life stages, he dropped dozens of clams in cold water and fed them for several weeks, then jacked up the water temperature, inducing a few males to release sperm. But his equipment was primitive, his clam food was riddled with bacteria and he couldn't get the larvae to grow reliably. If he could, he reasoned, perhaps the state could someday plant geoduck beds, much like people farm oysters.

At a state research hatchery in the 1980s, Goodwin and his colleagues succeeded in producing baby mollusks. Getting geoducks to grow after the creatures were transplanted was another matter. The researchers planted little geoducks and big ones, tucked them neatly in the sand and dumped them from boats, buried them in deep and shallow water. "We did at least 100 experiments and I think we planted 18 million clams on old, harvested beds," Goodwin said, laughing. Almost every time, the crop died.

Goodwin and I strolled past larvae-rearing tanks as big as brewery boilers. A tang filled the air, the smell of a fetid rain forest on a hot day. Down the hall, water-heater-size plastic bladders bubbled with shellfish feed—algae of varying hues, from mahogany to brilliant green.

By the mid-1990s, other biologists finished the work Goodwin began. They caged the clams in protective plastic cones covered with mesh, allowing the clams to burrow and grow while protected from predators. That practice, along with Goodwin's research, led to operations like this, run by a shellfish company called Taylor Resources, which provides months-old geoducks to clam farms.

Geoduck farmers place starter clams on tidelands leased from private landowners, poking thousands of plastic pipes through the surf like headstones. Acres of mesh netting blanket the operation. After four or five years, farmers, on foot, drag pressure hoses across the mud during low tides and dig out their harvest. Clam farms in Washington now sell nearly a million pounds of geoducks a year.

In traditional fish farms, salmon or cod may be fed pellets and crammed like hogs into net pens, from which diseases may spread to wild fish. But farmed geoducks, once planted, feed and grow naturally. "So far there have been no diseases known that spread from geoduck farms to a natural population," Goodwin told me, though "there may be down the line." Still, some environmentalists and coastal homeowners want to block new farms and have existing ones dismantled. Activists fear that the miles of clam farms now dominating some shallow bays may drive forage fish from Puget Sound's near shore. Residents also worry that the tons of sand turned over by geoduck harvesting smothers eelgrass beds serving as nurseries to young salmon. They complain that the plastic pipes and nets blow ashore in storms. To be sure, the environmental risks remain largely unknown. Scientists are just beginning to study geoduck aquaculture's impact on the Sound.

Some scientists also worry about the risks that farmed geoducks could pose to native populations. Hatchery-raised geoducks may not be as genetically diverse as wild ones, and some experts fear that transplanted geoducks that breed with natives could "change the genetic structure of wild stocks," says Brent Vadopalas, a biologist at the University of Washington. Anything that reduces genetic diversity could make wild populations less able to adapt in response to disease or changes in habitat. Could that alter long-term survival? "It's a legitimate concern," Goodwin concedes.

Today, at 70, Goodwin works as a consultant for another geoduck operation, Seattle Shellfish. He lives a ten-minute drive from Taylor Resources' hatchery, where he still does research in the company's lab. (His most recent study looked at how summer heat altered the burrowing speed of young geoducks.) "You'd think after playing around with the same critter for 40 years we'd know everything there is to know," Goodwin said. "But we've only scratched the surface." Besides, he told me in a whisper, "I think they're beautiful. Most people go ‘Eeeeew!' That's the first reaction you get. But they're absolutely gorgeous animals."

Craig Welch wrote about Northern spotted owls in the January issue. He is working on a book about wildlife thieves.
Natalie Fobes is a photographer and writer based in Seattle.

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