Plant foods: Important nutrients for the people of prehistoric Prince Rupert Harbour

We have made measurements of the stable carbon isotope ratio (δ13C) of the carbonate in the bones of humans from three ancient archaeological sites at Prince Rupert Harbour, British Columbia, Canada. The value of δ13C for carbonate in these samples shows that a large part of the energy supply (elemental carbon) of these people was derived from terrestrial plants. Berries are known to have been consumed in large amounts by the people native to this region. Tubers and other root-derived foods are also known to have been present in the diet of British Columbia coastal people. We show that these plant-based foods would have constituted 60 ± 10 % of the energy content of the diet.