Mobility among the stone age island foragers of Jettbole, ?land, investigated through high-resolution strontium isotope ratio analysis

The input of strontium from aquatic resources in an omnivorous diet has been researched to a lesser degree than that of terrestrial sources, which, in specific sociocultural settings, complicates the study of provenance and mobility. To address this lack of research and to investigate forager mobility in an archipelago environment, where access to terrestrial resources was limited and earlier studies have indicated a dependence on marine resources, we targeted the mid-Neolithic hunter-fisher-gatherers from the site Jettbo center dot le on the angstrom land Islands. Using laser ablation multi-collector inductively coupled plasma mass spectrometry, we analysed the 87Sr/86Sr ratios in the enamel of human and dog teeth and contextualized the data with bioavailable Sr measurements from various water and animal enamel sources. The results show that utilization and consumption of aquatic resources have had a major impact on the Sr ratios of both humans and dogs from Jettbo center dot le. The data indicate significant differences from the local terrestrial bioavailable Sr ratios, even if the studied individuals likely grew up in the area. Our results suggest that investigations of Sr isotope ratios may be especially challenging for PWC individuals and other coastal living groups. By comparing both Sr ratios and the sequential measurement pattern from the investigated subjects to other human groups and animals it has, nevertheless, been possible to offer a tentative interpretation of both the origin and mobility patterns of humans and dogs from Jettbo center dot le. Most of the individuals may be suggested to have originated, and subsided on a diet, from within the angstrom land archipelago. It is also possible that some of the studied individuals moved there from different regions.