image: Researchers in British Columbia, Canada excavate ancient shells from the beach of a "clam garden" -- a constructed rock-face terrace where Indigenous People cultivated clams. The clam garden fronts a 9,000 year old village that was supported in part by these cultivated clams. view more
Credit: Image courtesy of Mark Wunsch (Greencoast Media, British Columbia, Canada).
A study examines 11,500 years of shared history between butter clam and people in the Salish Sea in Western Canada. Tracking the relationship between humans and culturally and economically relevant species can inform ecological studies. In particular, ecological records of species cultivated by humans can show how traditional cultivation practices have affected the numbers and health of a species. Ginevra Toniello, Dana Lepofsky, and colleagues studied the growth of butter clams in the northern Salish Sea in British Columbia, Canada, over the last 11,500 years by measuring the overall size and the width of growth rings of clam shells from 5 beach sites. Clam size and age at death increased following the end of the last glacial period, suggesting improved habitat conditions. Middens indicating human harvesting of clams date to around 9,000 years ago, and by around 3,500 years ago, people began constructing clam gardens as a form of aquaculture. Traditional management practices meant that clam populations thrived during the aquaculture period, despite heavy harvesting pressure. According to the authors, traditional clam gardens were more productive than current untended clam beaches, suggesting that adopting traditional practices may help increase productivity of farmed marine species and maintain healthy ecosystems.
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Article #19-05921: "11,500 y of human-clam relationships provide longterm context for intertidal management in the Salish Sea, British Columbia," by Ginevra Toniello, Dana Lepofsky, Gavia Lertzman-Lepofsky, Anne K. Salomon, and Kirsten Rowell.
MEDIA CONTACT: Dana Lepofsky, Simon Fraser University, Burnaby, CANADA; e-mail: dlepofsk@sfu.ca
Journal
Proceedings of the National Academy of Sciences