Living in the shore: changes in coastal resource intensification during the Mesolithic in northern Iberia

Archaeological and Anthropological Sciences (2024) 16:79 https://doi.org/10.1007/s12520-024-01982-x RESEARCH Living in the shore: changes in coastal resource intensification during the Mesolithic in northern Iberia Rosa Arniz‑Mateos1 · Asier García‑Escárzaga2 · Ricardo Fernandes3,4,5,6 · Manuel R. González‑Morales1 · Igor Gutiérrez‑Zugasti1 Received: 8 December 2023 / Accepted: 25 March 2024 / Published online: 18 April 2024 © The Author(s) 2024 Abstract Recent research on human exploitation of molluscs, echinoderms and crustaceans during the Mesolithic in the Cantabrian region (northern Iberia) has shown significant variability in the intensity of the use of coastal resources by the last hunterfisher-gatherers throughout the ~ 4000-year expanse of the Mesolithic (10,700 – 6,700 cal BP). Previous studies have proposed hypotheses related to demographic changes to explain intensification events. In this paper we aim to unravel whether climatic and environmental changes, or other social factors, such as demography, were involved in the increase in the use of marine resources at certain times. We employed species representation, quantification and biometric analysis of the shell assemblages from the El Toral III archaeological site (Asturias, northern Iberia) to identify patterns in shell exploitation throughout the stratigraphic sequence. To establish the chronology and distinguish occupation phases of the site, we employed Bayesian modelling of radiocarbon measurements. Faunal results show that marine gastropods such as limpets of the Patella genus and topshells Phorcus lineatus (da Costa, 1778) were the most exploited species, while bivalves, echinoids and crustaceans were present in smaller quantities. The comparison of the results for El Toral III with other Mesolithic sites in the region reveals significant temporal differences in the intensity of collection of marine shell species. Results showed that intensification processes are not clearly related to climate change but to other social factors, such as demography, suggesting that intensification and relaxation in shell collection events were strategies adopted depending on the needs of the human groups at different times. Keywords Archaeomalacology · Prehistory · Marine resources · Molluscs · Shell midden Introduction * Rosa Arniz‑Mateos ; * Igor Gutiérrez‑Zugasti 1 Instituto Internacional de Investigaciones Prehistóricas de Cantabria (Universidad de Cantabria, Banco de Santander, Gobierno de Cantabria), Santander, Spain 2 Department of Prehistory and Institute of Environmental Science and Technology (ICTA‑UAB), Universitat Autònoma de Barcelona, Bellaterra, Spain 3 Department of Archaeology, Max Planck Institute for Geoanthropology, Jena, Germany 4 Department of Bioarchaeology, Faculty of Archaeology, University of Warsaw, Warsaw, Poland 5 Arne Faculty of Arts, Masaryk University, Brno, Czechia 6 Climate Change and History Research Initiative, Princeton University, NJ, Princeton, USA Archaeological and faunal evidence suggest that from the Upper Palaeolithic to the Mesolithic, there was an intensification in the exploitation of marine resources (Álvarez-Fernández 2009; 2013a; Cuenca-Solana et al. 2013; Gutiérrez-Zugasti 2009; Gutiérrez-Zugasti et al. 2013; García-Escárzaga 2020). During the Mesolithic, the number and size of shell middens, archaeological sites characterised by the predominance of shells in the stratigraphic matrix, increased across the coasts of Atlantic Europe (Milner et al. 2007; Gutiérrez-Zugasti et al. 2011), suggesting an intensive use of marine resources. In the Cantabrian region (northern Iberia), these deposits are commonly found in caves and rock shelters located less than 5 km from the modern coastline (Bailey and Craighead 2003; GutiérrezZugasti et al. 2011; Fano 2019). The quantity and quality of the archaeological record makes this region a key area for the Vol.:(0123456789) 79 Page 2 of 17 study of shell middens and long-term changes in subsistence strategies. Studies of Mesolithic sites in the Cantabrian region started at the beginning of the 20th century with the excavations of shell-midden sites, primarily in eastern Asturias, by the Count of Vega del Sella, from which the Asturian culture was defined (Vega del Sella 1923). The number of studies rose during the 1970s and 1980s with the excavation of sites such as La Riera, Balmori, Mazaculos II, and La Llana (González-Morales 1982; Clark 1983; Straus and Clark 1986). Towards the end of the 20th century and the beginning of the 2 1st century, new excavations of Mesolithic sites were carried out in Cantabria, at sites such as La Garma A (Arias et al. 2000), La Fragua (González-Morales 2000), and El Perro (González-Morales and Díaz Casado 2000), and in Asturias at sites such as Poza l'Egua (Arias et al. 2007), El Alloru (Arias et al. 2015), El Toral III (Noval-Fonseca 2013) and El Mazo (Gutiérrez-Zugasti et al. 2013). Excavations at the archaeological sites of El Mazo and El Toral III revealed the presence of exceptionally well-preserved Mesolithic shell middens which offered opportunities for the study of site formation processes, the exploitation of marine and terrestrial food resources (Marín-Arroyo et al. 2020; GarcíaEscárzaga and Gutiérrez-Zugasti 2021), technological and symbolic developments (Rigaud and Gutiérrez-Zugasti 2016; Fuertes-Prieto et al. 2021) and palaeoenvironments (García-Escárzaga et al. 2022a). The Mesolithic in northern Iberia ranged from 10,700 cal BP to 6,700 cal BP. Holocene enviromental conditions in coastal areas were characterised by increased temperatures but also by rapid abrupt cold climatic events, such as the 8.2 ka cal BP event, identified in the region at the site of El Mazo by decreased seawater temperatures and tree pollen reduction (Núñez de la Fuente 2018; García-Escárzaga et al. 2022a; b). Higher precipitation and humidity (Yanes et al. 2012), sea level rise throughout the period, with stabilisation of the coastline around 7.5-7 ka cal BP ago (Leorri et al. 2012) and the presence of forests predominantly composed by oaks, hazelnuts and birches (Núñez de la Fuente 2018) have also been recorded in the region. From a cultural point of view, the Mesolithic in the Western part of the region has been traditionally related to the Asturian culture. Lithic technology at this time was characterised by the predominant use of local raw materials for flake and laminar (blades and bladelets) production. Geometric microliths, although scarce, are also present in the archaeological record from nearly 8.3 ka cal BP ago (Fuertes Prieto et al. 2021). The most representative lithic tool is the Asturian pick, a quartzite cobble-made artefact knapped unifacially to form a pointed distal end (González-Morales 1982). Antler and bone tools are very rare, but fishing hooks and perforated antler batons have been found at some sites. Subsistence strategies were characterised by intense use of mari (...truncated)