A three-year study of ancient clam gardens in the Pacific Northwest has led researchers, including three from Simon Fraser University, to make a discovery that could benefit coastal communities' food production. PLOS ONE, a peer-reviewed science journal, has just published their study.
Amy Groesbeck, an SFU alumna, SFU professors Anne Salomon, an ecologist, and Dana Lepofsky, an archaeologist, and Kirsten Rowell, a University of Washington biologist are the authors.
The researchers discovered that ancient clam gardens made by Aboriginal people produced quadruple the number of butter clams and twice the number of littleneck clams as unmodified clam beaches. This is the first study to provide empirical evidence of ancient clam gardens' superior productivity.
In the past, as indigenous coastal communities from Alaska to Washington State grew in numbers, people needed to devise sustainable ways of feeding themselves. One of the ways they did this was by cultivating clams in human-made, rock-walled beach terraces known as clam gardens.
When the researchers transplanted more than 800 baby clams into six ancient clam gardens and five non-walled natural beaches to compare their growth rates they made a groundbreaking discovery.
The clams in the ancient gardens grew almost twice as fast and were more likely to survive than baby clams transplanted into unmodified beaches in the same area.
"We discovered that flattening the slope of ancient beach clam gardens expanded the real-estate for clams at the intertidal height at which they grow and survive best," explains Salomon. The School of Resource and Environmental Management assistant professor adds: "Traditional knowledge by coastal First Nations members further revealed that their ancestors boosted these gardens' productivity by adding ground clam shell and pebbles to them."
The researchers began their clam garden investigations in 2008. From 200
|Contact: Carol Thorbes|
Simon Fraser University