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Recent excavations at the sites of Strandvagen and Kanaljorden in Motala, Eastern Central Sweden, have unearthed complex and varied funerary remains from the Mesolithic. The two sites are situated ...

The harp seal (Pagophilus groenlandicus), today a subarctic species with breeding populations in the White Sea, around the Jan Mayen Islands and Newfoundland, was a common pinniped species in the Baltic Sea during the mid- and late Holocene. It is puzzling how an ice dependent species could breed in the Baltic Sea during the Holocene Thermal Maximum (HTM), and it remains unclear for how long harp seals bred in the Baltic Sea and when the population became extirpated. We combined radiocarbon dating of harp seal bones with zooarchaeological, palaeoenvironmental and stable isotope data to reconstruct the harp seal occurrence in the Baltic Sea. Our study revealed two phases of harp seal presence and verifies that the first colonization and establishment of a local breeding population occurred within the HTM. We suggest that periods with very warm summers but cold winters allowed harp seals to breed on the ice. Human pressure, salinity fluctuations with consequent changes in prey availability and competition for food resources, mainly cod, resulted in physiological stress that ultimately led to a population decline and local extirpation during the first phase. The population re-appeared after a long hiatus. Final extinction of the Baltic Sea harp seal coincided with the Medieval Warm Period. Our data provide insights for the first time on the combined effects of past climatic and environmental change and human pressure on seal populations and can contribute with new knowledge on ongoing discussions concerning the impacts of such effects on current arctic seal populations.

Of central importance to palaeodietary reconstruction is a clear understanding of relative contributions of different terrestrial (i.e., C3 vs. C4 plants) and aquatic (i.e., freshwater vs. marine) resources to human diet. There are, however, significant limitations associated with the ability to reconstruct palaeodiet using bulk collagen stable isotope compositions in regions where diverse dietary resources are available. Recent research has determined that carbon-isotope analysis of individual amino acids has considerable potential to elucidate dietary protein source where bulk isotopic compositions cannot. Using δ13CAA values for human and faunal remains from Zvejnieki, Latvia (8th – 3rd millennia BCE), we test several isotopic proxies focused on distinguishing freshwater protein consumption from both plant-derived and marine protein consumption. We determined that the Δ13CGly-Phe and Δ13CVal-Phe proxies can effectively discriminate between terrestrial and aquatic resource consumption, and the relationship between essential δ13CAA values and the Δ13CGly-Phe and Δ13CVal-Phe proxies can differentiate among the four protein consumption groups tested here. Compound-specific amino acid carbon-isotope dietary proxies thus enable an enhanced understanding of diet and resource exploitation in the past, and can elucidate complex dietary behaviour.

The infant feeding practices used at the Pitted Ware Culture (PWC) site of Ajvide on the Baltic island of Gotland were investigated using carbon and nitrogen stable isotope ratio analysis. The PWC weremarine hunters with a seal-based economy who lived in the Baltic region during the Middle Neolithic, and were contemporary with the farming Funnel Beaker and Boat Axe Cultures. The carbon and nitrogen stable isotope ratios of bone collagen from adult females (14 individuals) and bone and dentine collagen from subadult individuals (23 individuals, 55 samples) from Ajvide were analysed. The results showed that the majority of infants continued breastfeeding into the third or fourth year of life. There was some variation in the types of supplementary foods used and the timing of their introduction, perhaps due to seasonal variation in the availability of different resources. One infant, a neonate, had carbonand nitrogen isotope ratios indicative of a much more terrestrial diet than usually consumed by the PWC, suggesting contact with the Neolithic farming populations in the Baltic region. Comparison of the results from Ajvide to those from other PWC sites in the Baltic region reveals that both adult and subadult dietary practices differed slightly between sites. LeCHE

We present here a framework for using stable isotope analysis of bone and teeth to study individual life history. A sampling strategy and analytical approach for stable carbon and nitrogen analysis of bone and dentine collagen optimised for intra-individual purposes is put forward. The rationale behind this strategy, various requirements and constrains, and recommendations on how to modify it according to variations in material and analytical instrumentation, are discussed and explained in detail. Based on intra-individual data for 131 human individuals from Mesolithic and Neolithic sites in Northern Europe, we consider the sources and various kinds of variation one is likely to find, and how the data can be explained and transformed into an archaeologically meaningful interpretation. It is concluded that the use of stable isotope analysis to trace individual life history is not limited to carefully excavated, neatly preserved, single burials with articulate skeletal remains. Even collective burials, disturbed graves, disarticulated human remains in cultural layers, or other depositions that deviate from what is often considered as a “proper burial”, offer the possibility to look at individual life biographies.

The Mesolithic–Neolithic transition in north-west Europe has been described as rapid and uniform, entailing a swift shift from the use of marine and other wild resources to domesticated terrestrial resources. Here, we approach the when, what and how of this transition on a regional level, using empirical data from Öland, an island in the Baltic Sea off the Swedish east coast, and also monitor changes that occurred after the shift. Radiocarbon dating and stable carbon and nitrogen isotope analyses of bones and teeth from 123 human individuals, along with faunal isotope data from 27 species, applying to nine sites on Öland and covering a time span from the Mesolithic to the Roman Period, demonstrate a great diversity in food practices, mainly governed by culture and independent of climatic changes. There was a marked dietary shift during the second half of the third millennium from a mixed marine diet to the use of exclusively terrestrial resources, interpreted as marking the large-scale introduction of farming. Contrary to previous claims, this took place at the end of the Neolithic and not at the onset. Our data also show that culturally induced dietary transitions occurred continuously throughout prehistory. The availability of high-resolution data on various levels, from intra-individual to inter-population, makes stable isotope analysis a powerful tool for studying the evolution of food practices.

The Middle Neolithic Pitted Ware Culture on the Baltic Sea islands comprised a common identity distinguished, in part, by an almost exclusively marine diet. Based on evidence from the first stable isotope analysis on Pitted Ware skeletal material from the Eastern Central Swedish mainland, we suggest that this identity was shared by PWC groups in the archipelago of the west side of the Baltic. Fifty-six faunal and 26 human bone and dentine samples originating from the Pitted Ware site Korsnas in Sodermanland, Sweden were analysed, and the data clearly shows that the diet of the Korsnas people was marine, predominantly based on seal. The isotope data further indicate that the pig bones found in large quantities on the site emanate from wild boar rather than domestic pigs. The large representation of pig on several Pitted Ware sites, which cannot be explained in terms of economy, is interpreted as the results of occasional hunting of and ritual feasting on wild boar, indicating that the animal held a prominent position, alongside seal, in the hunting identity and cosmology of the Pitted Ware people. Further, eleven new radiocarbon dates are presented, placing the Korsnas site, with a large probability, within Middle Neolithic A.

A case study of the Pitted-Ware site of Vasterbjers on Gotland in the Baltic Sea forms the starting point for a discussion on the cultural identity, economy, and chronology of this culture. Extensive and detailed stable isotope data on both the prehistoric fauna (87 samples from 20 faunal species) and human remains (65 samples from teeth and bones of 26 individuals) show that the Vasterbjers population, and most likely the whole Pitted-Ware Culture on Gotland, practised mainly seal hunting but no animal husbandry. The hypotheses that they belonged to the same group who practised farming (i.e., the Corded-Ware culture) can therefore be refuted. The Pitted-Ware Culture on Gotland evidently represented a separate group with a cultural identity of its own, and the seal was an important feature in that identity. Eighteen new radiocarbon dates suggest that the Vasterbjers cemetery was in use for at least a couple of 100 years, during the period 2900–2500 cal BC, but there is no support for the proposed chronological division of the cemetery into two spatially separate halves. A calculation of the age offset caused by the marine reservoir effect for Middle Neolithic Gotland demonstrates a considerably smaller offset than previously suggested, 70 ± 40 radiocarbon years.