Alaska peninsula stable isotope and radioisotope chemistry: a study in temporal and adaptive diversity

Purified bone collagen from a small suite of human remains recovered at three sites on the Alaska Peninsula (Port Moller, Brooks River, and Mink Island) were analyzed for stable carbon and nitrogen isotope chemistry and were accelerator radiocarbon dated. Because samples sizes were small and faunal isotope chemistry lacking, results should be considered preliminary. However, these data indicate that each locality was represented by a somewhat different suite of subsistence strategies and covered a distinct temporal span. Port Moller burials (n = 7) from the Hot Springs site date to a calibrated 2σ range of 3547-1388 BP. Although marine foods clearly made the greatest contribution to these diets, individuals were not as heavily reliant on high-trophic-level marine taxa as eastern Aleutian groups to the west, given their intake of salmon and evidence of caribou hunting. Brooks River burials (n = 9) expressed an inland foraging focus with significant reliance on caribou and spawning salmon and covered a calibrated 2σ range of 1484-381 BP. In contrast, individuals from Mink Island (n = 7), dating to cal. 666-292 BP, were heavily reliant on high-trophic-level marine prey similar to but not as enriched isotopically as the Aleut, perhaps a consequence of limited access to caribou and greater reliance on invertebrates. This pattern suggests that prehistoric economic strategies on the Alaska Peninsula were diverse, characterized by fine-tuned adaptations to local ecological settings, perhaps mediated by ethnic factors and territorial and social pressures.