Feeding patterns of marine euryhaline fish and their impact on hunter-gatherer diets during the Mid-Late Holocene in the eastern Pampa-Patagonia transition (Argentina)

Abstract

Subsistence has been one of the most widely discussed topics concerning the archaeology of hunter-gatherer groups who inhabited the eastern Pampa-Patagonia transition (Argentina) since ca. 6000 years BP. Previous studies on human paleodiets through the analysis of stable isotopes (δ13Cap, δ13Ccol and δ15N) indicate that during the Middle Holocene (~6000–3000 years BP / ~6700–3100 years cal BP), terrestrial herbivores, marine fish, and possibly pinnipeds played an essential role in their diet. Towards the Late Holocene (~3000–250 years BP / ~3100–250 years cal BP), terrestrial herbivores and freshwater fish increased in importance, while the consumption of marine resources declined. However, archaeofaunal assemblages from the San Antonio Archaeological Locality demonstrate seasonality in coastal occupations and occasional intensive exploitation of euryhaline fish from ~1000–800 years BP. Although a solid isotopic baseline for the terrestrial ecosystem has already been established for the study area, there is still a need to understand the marine and estuary environments. This paper aims to present and discuss stable isotope information (δ13C and δ15N) from archaeological and modern marine and euryhaline fishes (Genidens barbus, Micropogonias furnieri, Cynoscion guatucupa, Conger orbignyanus and Mustelus schmitti), with emphasis on sea catfish (Genidens barbus) and whitemouth croaker (Micropogonia furnieri). This provides a better understanding of the characteristics of the feeding pattern of fish for adequately interpreting human paleodiets. The results indicate diets consisting of mainly marine species although individuals of anadromous species present both marine and freshwater diets. Analysis considered factors such as the ontogeny of each species, variations in food sources, paleoenvironmental conditions, migratory patterns, as well as the implications for the interpretation of human paleodiets.