@article{10902/35243,
year = {2020},
month = {12},
url = {https://hdl.handle.net/10902/35243},
abstract = {Stable oxygen isotope ratios of mollusc shells (δ18Oshell) offer the possibility to reconstruct coastal resource exploitation patterns and changes in the oceanographic conditions of direct relevance to past human populations. This method relies on the fact that shell carbonate is deposited by molluscs in equilibrium with their surrounding environment and actualistic investigation of modern specimens is needed to ensure that selected species can be used as accurate palaeoclimate indicators. The limpet Patella depressa Pennant, 1777 is one of the most common mollusc species found in Holocene archaeological assemblages along the Atlantic coast of Europe. However, this taxon has not, to date, been tested as a seawater palaeothermometer. Here, we explore the ability of P. depressa to be used as an environmental recorder in this littoral region, specifically in northern Iberia where we obtained livecollected specimens throughout the year. We undertook sclerochronological investigations combining observations of incremental shell growth patterns with δ18Oshelll values. Carbonate samples were taken on (i) the ventral margins of shells collected alive year-round in order to test for isotopic equilibrium and (ii) along the axis of maximum shell growth of four modern specimens to decipher the shell growth pattern of this species. Isotopic data showed that calcium carbonate is precipitated in predictable isotopic disequilibrium with the ambient seawater (R2 = 0.95; p < 0.0001), reporting a consistent offset of +1.08‰. Some periods of growth cessation were observed in the shells when thermal tolerances were exceeded in winter and occasionally in summer. Nevertheless, estimated seawater temperatures from modern shell δ18Oshell values agreed closely with instrumentally measured temperatures (R2 = 0.88–0.93; p < 0.0001) and correctly reflected seasonal temperature patterns. As a result, multi-proxy analysis of P. depressa shells can provide a high-resolution palaeothermometer with significant implications for future palaeoclimate and archaeological studies along the Atlantic coast of Europe.},
organization = {This research was performed as part of the projects HAR2016-75605-R and HAR2017-86262-P, funded by the Spanish Ministry of Economy and Competitiveness (MINECO). AGE is currently supported by the Basque Country Postdoctoral Programme (POS_2019_2_0005). This study has also been supported by the Prehistoric Research Consolidated Group of the Basque Country University (IT1223-19), funded by the Basque Country Government. We thank the Fishing Activity Service of the Cantabrian Government for the authorization to collect modern specimens, the Aquaculture Facility of Santander's Oceanographic Centre for providing the information related to sea surface temperatures and José Ramón Mira Soto for his help measuring salinity. PR and JZ thank the Max Planck Society for Funding. We would also like to thank to Max Plank Institute for Science of Human History (MPI-SHH), Basque Country University (UPV/EHU), Universidad de Cantabria (UC), and Instituto Internacional de Investigaciones Prehistóricas de Cantabria (IIIPC) for providing support. We would also like to thank Roberto Suárez-Revilla, Sara Marzo, Bianca Fiedler, Mary Lucas, Elsa Perruchini and Lucia Agudo-Pérez for their help.},
publisher = {Elsevier},
publisher = {Palaeogeography, Palaeoclimatology, Palaeoecology, Volume 560, 15 December 2020, 110023},
title = {Shell sclerochronology and stable oxygen isotope ratios from the limpet "Patella depressa" Pennant, 1777: Implications for palaeoclimate reconstruction and archaeology in northern Spain},
author = {García-Escárzaga, Asier and Gutiérrez Zugasti, Fernando Igor and González Morales, Manuel R. and Arrizabalaga, Álvaro and Zech, Jana and Roberts, Patrick},
}