The coastal areas of the Pacific Northwest were among some of the most densely populated parts of Native North America. At the time of European contact, it is estimated that 150,000 Indigenous people lived in the Salish Sea region which spanned from “the north end of the Strait of Georgia to the south end of Puget Sound and west to the mouth of the Strait of Juan de Fuca.” How were the people Native of the Salish Sea able to support such large populations, without anything that Europeans would have recognized as agriculture? The answer is that the Indians farmed the sea.
The Natives of the Salish Sea made shellfish a very large part of their diets. They enjoyed little-neck clams, butter clams, oysters, mussels, and XX. Barnacles, in particular, were a delicacy. Natives used the bounty of their marine-harvest primarily for sustenance but not exclusively. They are expert ecologists, timing shellfish harvests for maximum yield and habitat sustainability. They went even further, creating shellfish habitat in the form of extensive and sometimes elaborate “clam gardens” at the tidal margins.
Clam gardens were built on Orcas Island by the Lummi people as early as 2,000 years ago. Natives constructed rock walls near the zero tide line. The wall would produce a terrace on the land-side of the wall, greatly expanding the zone of optimal habitat for clams and other shellfish.
These clam gardens produced four times as many clams as non-walled beaches. Research also shows that clams grown with Indigenous mariculture grew nearly twice as fast, were more likely to survive, and grew to double the biomass. Salish Sea Natives relied on harvesting this food source to sustain a large population.
The creation and maintenance of clam gardens called “Wuxwuthin” by many Coastal Salish Nations, were also culturally important. Native people passed the knowledge of clam mariculture on to the next generation through stories, songs, and dances. The construction of rock walls and the harvesting of clams were important family events in which the proper techniques were learned by the next generation. Clam gardens were often controlled by specific families and in certain societies only families of high status. There is some evidence to suggest that communal untended clam gardens were open to all.
While recorded ancient clam gardens are common in the waters surrounding Vancouver Island, especially on Quadra Island, there is an absence of these discoveries in Washington State throughout the Salish Sea and Puget Sound region. Industrial shoreline development and rising sea levels have hidden countless ancient clam gardens throughout the Salish Sea. This has made it especially difficult to pinpoint the location of Wuxwuthin in the San Juan Islands. However, the presence of large deposits of shell middens (places where the debris from eating shellfish and other food has accumulated over time) near the shores of American and English Camps is evidence to the extensive sea farming that was vital to indigenous life in the San Juans for thousands of years. Local tribes are currently working to fight water contamination that is sabotaging the success of some modern indigenous clam gardens.