There’s been quite a bit of buzz surrounding a new paper by Carrin Halffman et al. documenting the use of salmon at the Upward Sun River Site (more) which is on the Tanana River: a tributary of the Yukon River, but about 1,400 kilometres upstream from the ocean (and much further still from the paleo-rivermouth during Beringian times). The authors report this as both the earliest evidence of salmon exploitation in the Americas, and the first evidence of Pleistocene salmon use. The first I am on board with, the second I may quibble a little with lower down. (And this is all assuming we don’t consider eastern Beringia to be effectively part of Asia at this time!). But it’s a remarkable find and a very carefully researched and presented paper. [edit: be sure to read comments from Ben Potter below which tweaks some information in this post.]
My first reaction on reading that these were Chum salmon (Oncorynchus keta) was “no way, that species only migrates upriver a few tens, or maybe a hundred kilometres. Certainly not well over 1,000 km from saltwater”. Turns out this is true for most Chum salmon, but the Yukon River Chum do run that far upriver – this site is near the uppermost range they reach on the system. So Chum is certainly plausible. My second reaction was, “How do they know it is Chum?”, since salmon remains are notoriously difficult to tell apart – that is, it’s hard to tell a coho vertebra from a sockeye, etc. Turns out that they used ancient DNA extraction to verify these remains as Chum salmon. Well, when I say “these remains”, it appears they extracted DNA from two specimens from a total of over 300. They tried three, but had success with only two (fairly miraculous to have any success at all, really). This low sampling density is a little puzzling. At least one sample aDNA ID was replicated in an independent lab. The dates seem tight and the components are well defined and there are other fauna and artifacts galore.
To further solidify these as anadromous (marine fish which run up rivers to spawn) versus (I suppose) potentially landlocked Chum of some kind (analogous to landlocked sockeye, also known as kokanee), they performed stable isotope analysis on the specimens. They were able to convincingly show these were fish that spent their lives in a marine environment. I mean, I don’t think there are any known landlocked Chum, but perhaps there were in the past? It’d seem aDNA would settle it but it’s good to see them go the extra mile.
The early dates are quite exciting. This is in the heart of Beringia, where some models of the early peopling of the Americas would have us believe the big game hunters responsible for killing off the now extinct American megafauna originated. Fishing is pretty manly in my books, but is not commonly associated with the hyper-manly “PaleoIndian” period. Well, there’s not much evidence for fishing then, but since fish exploitation is known for literally two million years, it’d be safe to assume it was in the capabalities of Homo sapiens. Sometimes I get the impression that we think of Beringia as a giant culture-eraser, so the early people of the Americas must be shown all over again to have basic adaptive skills which are well established all over Eurasia for tens of thousands of years. Like, archaeologists think they lost their well-established Upper Paleolithic skillsets and had to start all over again. Watercraft is another that comes to mind. Maybe it’s less scientific or something, but wouldn’t we be further ahead if we had just assumed people 10-15,000 years ago in the Americas were familiar with boats?
OK, I digress. My slight quibble is not that this isn’t a fantastic and important site for understanding early North American archaeology. Rather it’s around terminology. If the Pleistocene is understood as ending at the end of the Younger Dryas interval, caa. 11,700 calendar years ago, then are these actually Pleistocene? Not quite, perhaps. However, if, as is common, we use 10,000 calendar years as a convenient shorthand for the end of the Pleistocene, then there other sites bearing salmon or salmon-related that qualify. Just off the top of my head, there were trace amounts of salmon at Kilgii Gwaay (10,700 years ago), and in hearths at Richardson Island dating to between 10,000 and 10,400 years ago. In fact, 25% of the hearths at Richardson contain calcine salmon (Steffen, MA thesis). Both sites are in Haida Gwaii. If memory serves (and it’s too late to put my scotch down and waddle across blog headquarters to check) the Milliken site on the Fraser has basal dates of about 9,200 years 14C, or about 10,300 calendar years, or so? The location of this site in the midst of prominent salmon-rich eddies at the base of a steep river canyon makes little sense except as a salmon fishing station. And I think there were charred seeds indicative of fall occupation there as well. So despite the lack of salmon bones it’s a fairly safe inference. Anyway, it’s all terminological I guess – it’s the age it is, even if the label is arguable. If I had to, I’d choose the end of the Younger Dryas cold interval as the true end of the Pleistocene, so these remains are indeed very close to that age.
I was also a little surprised at the lack of comment on the context of these salmon remains. It appears they are sandwiched between and amongst two burial features, including three individual children, none older than age four. In fact, the context for the salmonids is described as “cremation hearth” and “burial pit fill”. Maybe the significance here is not just eating salmon, but ritual deposition of salmon in mortuary practice? It’d be nice to see this discussed head on. In an earlier paper (Potter et al. 2014) a variety of grave goods and ritual treatment of these dead children is described. However, the salmonid remains (as then known) were described as being incidental to the burial contexts. I mean, I’m not going to second guess the assignments of association from my sofa, and certainly not those of Ben Potter! However, my point is, the ritual use of food in funerary ritual is extremely widespread. Whether we consider these food remains to be just functional as foodstuffs, or implicated in a bigger system of meaning, affects how we think about, and therefore research, these early inhabitants. If we don’t explicitly acknowledge spirituality, or demand unequivocal evidence for that which may always be equivocal, (and no mention of this in the new paper) it may skew our research. Just as if we don’t allow these people the skills to catch fish, small game, or use plants we may not even attempt to recover microfauna or archaeobotanical remains.
Halffmann, Carinn et al, 2015 (preprint – institutional access only). Early human use of anadromous salmon in North America at 11,500 y ago. Proceedings of the National Academy of Sciences, in press.
Ben A. Potter, Joel D. Irish, Joshua D. Reuther, and Holly J. McKinney 2014. New insights into Eastern Beringian mortuary behavior: A terminal Pleistocene double infant burial at Upward Sun River PNAS 2014 111 (48) 17060-17065.