Alaska – Researchers found in Alaska the earliest known evidence that ancient humans in North America consumed salmon by the last Ice Age. The study, which was published in the Proceedings of the National Academy of Sciences, contradicts the common belief that Ice Age Paleoindians were mainly big-game hunters, who usually chased animals such as mammoths and bisons.

Ben Potter and colleagues from the University of Alaska Fairbanks, found a 11,500 year old chum salmon bones at the Upward Sun River site in Alaska. Previous excavations at the site have unearthed human dwellings, tools and humans remains, and now, the salmon bones.

Two natives use a pole to carry freshly caught salmon filets for drying at a village in Alaska. Native people, who once celebrated the return of salmon with elaborate ceremonies, still net and dry salmon much as they did thousands of years ago. Today, echoes of these traditional celebrations survive in Alaska Native salmon stories and contemporary art. Photograph taken on assignment for The Nature Conservancy “Design For A Living World” project and exhibit. 2008. Credit: Amy Vitale.

“Salmon fishing has deep roots, and we now know that salmon have been consumed by North American humans at least 11,500 years ago,” said lead author Carrin Halffman, a UAF anthropologist who helped analyze the fish bones.

The Discovery

About 300 salmon bone fragments were found in an ancient cooking fireplace in a residential structure, indicating the beginning of salmon exploitation. Fish remains represent a special challenge to archaeologists because their bones are very small and fragile and do not preserve well.

After evaluating the remnants by ancient DNA and stable isotope analysis, the team confirmed that it was indeed a sea-run chum salmon that migrated upriver about 1,400 km from where the mouth of the Yukon River is now located.

This result shows that modern salmons migrations may have ancient roots, even dating back to the last Ice Age, approximately 110,000 to 12,000 years ago. It also suggests that salmon spawning goes back to much earlier and much north that what was previously thought.

Researchers work on excavation at the Upward Sun River site in Alaska. Photo courtesy of Ben Potter, UAF

“We have cases where salmon become landlocked and have very different isotopic signatures than marine salmon. Combining genetic and isotopic analyses allow us to confirm the identity as chum salmon, which inhabit the area today, as well as establish their life histories,” said Potter.

Additionally, Potter explained that the finding demonstrates that ancient Beringian diets were more extensive than believed and that Ice Age Humans used specialized technology and complex strategies to obtain their food.

“This suggests that salmon fishing may have played a role in the early human colonization of North America,” he added.

Source: PNAS