In August 2022, members of the Swinomish Tribal Community set up a human chain on Kiket Island, an islet jutting off their reservation in western Washington state. They and their friends passed rocks from hand to hand across the beach, down to the water’s edge. They were building something both old and new—a clam garden that resembles those designed by their ancestors.
The Swinomish Tribe's clam garden, which was originally built in 2022 and is being reinforced here by attendees of the 2023 Salish Summit, is the first contemporary Indigenous clam garden to be constructed in the United States.
Photo by EJ Harris
Butter clams and other clam species being cultivated tend to thrive on gravely beaches clear of seaweed and bathed with warm, moderate currents to wash in the plankton they eat.
Photo by Julie Barber
The key to a clam garden is its stone wall up to a few feet high, facing a stretch of beach at the level of the low tide. The wall entraps sand and gravel, flattening the slope of beach and expanding the area where clams can thrive, buried in sand between low and high tide levels.
Clam gardens were not built in a day, however. They ranged in size from small coves to a half mile long and took years of effort, not only to construct but also to maintain in the face of the ceaseless tug of tides and storms. “In ancient times, building a clam garden probably took generations,” said lifelong fisherman Joe Williams, who as the shellfish community liaison for his Swinomish Indian Tribal Fisheries Department helped lead the construction project.
For millennia, Indigenous peoples living along coasts from Alaska through Canada to Washington state created such gardens to bolster harvests of butter, horse and native littleneck clams as well as cockles by building short rock walls at the low-tide line from stones they found on the beaches. Dana Lepofsky, an archaeologist at Simon Fraser University in Burnaby, British Columbia, and her colleagues dated organic material under ancient clam garden rock walls as being at least 4,000 years old.
Although most clam gardens fell out of use after European colonization and the consequent growth of the cash economy, knowledge of their use in the Pacific Northwest was never fully lost. A few Kwakwaka’wakw elders in the Broughton Archipelago in British Columbia remembered learning their ancestors’ ways of maintaining the gardens during the 1930s and 1940s. Aerial exploration of the British Columbia coast in 1995 revealed remnants of rock walls and finally brought clam gardens to the attention of Western science.
Stone walls alone, however, do not make a clam garden. Diggers who harvest the clams also rake the sand, turning it over to let the tide wash away silt and debris, enabling nutrients in ocean water to flow more efficiently to the remaining clams. Raking also reduces the organic content in the sediment that produces hydrogen sulfide as it decays, which is toxic to young clams.
Aside from fashioning a home for clams, the rock walls also provide habitat for mussels, crabs, chitons, sea cucumbers, limpets, small fish and octopuses. Some of those creatures are edible by humans and some are food for larger predatory fish, which are in turn food for coastal peoples.
While management differed between communities, clam gardens were often managed by a particular family, which probably kept gardens in more than one place, said Lepofsky. “People traveled by canoe so they didn’t need to have a garden outside their front door,” she said. “Clam gardens are about making a good living, respecting nonhuman kin and thinking about the future.”
“The Swinomish host several community events a year where tribal members come and tend to their garden,” said Julie Barber, senior shellfish biologist for the Swinomish Indian Tribal Community. “The tribe will always be there on the beach, tending to their garden and ensuring aspects of future food security for their people.”
“Food systems are all about productivity—how much you can harvest each year,” explained Marco Hatch from the Samish Indian Nation who is an associate professor of Environmental Science at Western Washington University. Compared to natural, unwalled beaches, clams in gardens increase in numbers and grow faster to a harvestable size.
Other cultural practices contribute to the harvest over the long run. Self-imposed collecting limits mean that smaller clams are left behind, for instance, allowing them to grow bigger for future harvests. Returning whole or crushed clam shells to the beach recycles calcium carbonate, which the clams use to build their shells and also serves to mitigate cold and heat, especially when the lowest tides come in on a summer midday, explained Hatch.
Farther north, in Canada’s British Columbia, Nicole Norris is an aquaculture specialist and member of the Halalt First Nation in the Hul’q’umi’num Territory on Vancouver Island. She remembers toting four-prong potato rakes and five-gallon plastic buckets down to the beach to dig for clams as a youth. Mixing traditional knowledge with Western science, she later learned both from tribal elders and university researchers about how clams grow and how different shore types, water salinity and air and water temperatures affect the clams. They tend to thrive on gravely beaches clear of seaweed and bathed with warm, moderate currents to supply the plankton they eat.
Norris and her colleagues have found the remains of more than 50 clam garden walls in British Columbia, of which four are being restored. “It took years of labor and thousands of pounds of rocks at several different locations to build them,” said Norris. “We should only restore a clam garden today if we know that someone will continue to maintain it. We want to promote food security and see that clams become a food source for these communities.”
Sea gardens always were, and continue to be, a climate change adaptation strategy. “The Coast Salish moved their clam garden walls up and down the beach over generations in response to rising or falling sea levels,” said Williams. “Our ancestors left us a playbook for how to adapt and be good stewards in the face of climate change. So the clam gardens will make us a little more resilient when it comes to our food in the future.”
For instance, seaweed was traditionally gathered from clam beds to fertilize trees in nearby forests. As storms are becoming more severe and more frequent in changing climates today, keeping those forests healthy means strong root systems can retain soil and reduce runoff during heavy downpours. This can prevent silt from washing seaward and choking marine life.
Restoration of clam gardens can not only revive seashore environments but also parts of Coast Salish life. “Colonization cost us a site-specific portion of our language and culture,” said Williams. “Words naming or describing a place go unused when we are not in those places.”
Williams didn’t fully realize that until an elder told him the story of coming to Kiket Island decades ago to dig horse clams with his elderly aunts when he was a boy. One of the women went out to dig clams, another gathered wood and built a fire, and the third prepared the clams for smoking. Just being on the site again brought memories back to the elder.
“Bits and pieces of our stories and songs will come back as people cultivate these beaches,” said Williams. “I can feel the presence of my ancestors when I visit a clam garden. This project is making our culture return to life.”