Salmon bones reveal Ice Age fishing holes

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Researchers in Alaska have found the earliest known evidence that Ice Age humans in North America used salmon as a food source. A new paper published on Monday in the

Proceedings of the National Academy of Sciences asserts that chum salmon have been harvested in Alaska for 11 thousand years.

The findings are based on analysis of 11,500-year-old chum salmon bones found by University of Alaska Fairbanks anthropologist Ben Potter and colleagues at the Upward Sun River site in Interior Alaska.

“So, when we found these fish remains, we were able to identify them to some level of specificity, but what this paper does, really nails the species through ancient DNA analysis, with is chum salmon, and also isotopic analysis lets us say that they were anadramous, that is sea run. they are just like modern salmon they spend part of their life in the sea and they spawn in fresh water streams. So one of the I guess, implications of this are quite surprising. We really had no evidence that people were doing this, or that salmon were even there.”

Excavation of the site has revealed human dwellings, tools and human remains, as well as the salmon bones.

“The site is quite exciting, it’s a multi-component site, and by that I mean that we have evidence of different cultures occupying the site at different times, all the way from over 13,000 years ago into the Middle Holocene, so maybe about 5,000 years ago. Because it is well, very deeply buried and well stratified, we can get information about specific occupations, different peoples that were at the site over time, and look at how their lifeways varied.”

The ancient chum salmon migrated upriver near where the mouth of the Yukon River now exists. These analyses indicate that modern salmon migrations may have ancient roots, dating back to at least the end of the last Ice Age.

The findings also suggest that salmon spawning runs were established much earlier and much farther north than previously thought.

UAF anthropologist Carrine Halfmann helped analyze the bones.

“This is the tail end of the Ice Age, so this provides direct evidence for the first time of humans capturing salmon this early, and that indeed salmon were available in Interior Alaska.”

The Upward Sun River site is located between Delta Junction and Fairbanks.

The salmon were found in an ancient cooking hearth in a residential structure. Fish remains pose a challenge to archaeologists because their bones are very small and fragile and typically do not preserve well. Because of these challenges, their remains are likely underrepresented in global archaeological studies and findings.

The findings show that Ice Age humans used complex strategies and specialized technology to obtain their food, Potter says

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