What is it about?

Around the world, Indigenous Peoples have been using their multi-generational, age-old knowledge to manage culturally important ecosystems. This knowledge involves culturally proscribed ways of interacting with the world so that resources can be harvested sustainably. Often this knowledge is invisible in the archaeological record and thus not apparent to people outside of these cultural traditions. In addition, stone features, while visible, are difficult to date based on standard archaeological techniques . On the Northwest Coast of North America, “clam gardens” are the striking physical evidence for the long-term management of intertidal ecosystems. These rock-walled terraces were created at the lowest-low tide levels to maintain and increase productivity of clams – foods that have been central to Northwest Coast cultures for millennia. While known to Indigenous Peoples throughout time, as indicated in ancestral stories and languages, western scientific researchers only accepted the presence of clam gardens in the last decade or so. Our research picks up on previous clam garden research conducted by the Clam Garden Network (www.clamgardens.com) on Quadra Island, British Columbia – where there is a very high density of clam gardens and ancient human settlements. We use novel techniques to date these rock wall features and find that they began to be created at least 3500 years ago, and probably longer ago. Based on local knowledge and the archaeological record, they continued to be used and maintained until quite recently.

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Why is it important?

Documenting the age and extent of these features is a fundamental step to recognizing Indigenous mariculture knowledge and also to supporting Indigenous marine food sovereignty going forward. In combination with Indigenous ways of knowing, this project demonstrates, once again, the extent and depth of Indigenous management practices and the deep value of understanding that knowledge in today's changing global cultural and ecological landscapes.


We are so excited to have honed ways to document these ancient management features. Doing so requires three crazy hours of excavating during the low-low tide window. Mud is flying, as rocks are removed, notes are taken, and samples are extracted and measured. We only have five such days in the months of May - August, when the tide is low enough to dig into these features. So, it's both exciting and a huge privilege!

Dana Lepofsky
Simon Fraser University

Read the Original

This page is a summary of: 3500 years of shellfish mariculture on the Northwest Coast of North America, PLoS ONE, February 2019, PLOS,
DOI: 10.1371/journal.pone.0211194.
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