Data/hora: 13/06/2024 10:43:29

Provedor de dados: | 5
País: | France
Título: | Oxygen isotope disequilibrium in the juvenile portion of oyster shells biases seawater temperature reconstructions
Autores: | Huyghe, Dimitri; Emmanuel, Laurent; De Rafelis, Marc; Renard, Maurice; Ropert, Michel; Labourdette, Nathalie; Lartaud, Franck.
Data: | 2020-08
Ano: | 2020
Palavras-chave: | Stable isotopes; Paleoclimatology; Sclerogeochemistry; Sclerochronology; Kinetic isotope effect.
Resumo: | For decades, bivalve shells have constituted one of the most common supports for paleoclimatic archives based on stable isotope approaches. In this work, we conducted chemical marking and recapture techniques to study the fluctuation of δ18O values of oyster shells of the species Magallana gigas reared in natural environment in Normandy (France) for two years. The results were compared to the continuous monitoring of temperature and salinity and monthly records of seawater δ18O. Isotopic measurements were performed on the hinge area that regroups the whole life of the oysters. Here we demonstrate that oysters mineralized their shells with no significant growth breaks during the two-years experiment, even at temperatures below 6 °C. The results confirm that adult oysters (i.e. &gt; 1 yr) mineralized their shells at equilibrium. However, juvenile specimens exhibit a strong isotopic disequilibrium, with a maximum shift of the δ18O values of 3‰ in winter, likely due to kinetic isotope effects. This corresponds to a reconstructed temperature up to 13 °C warmer than expected. This work indicates that although these oyster shells can be used as an accurate archive of (paleo)environmental conditions, the shell portion mineralized during the juvenile stage (i.e. &lt; 1 yr) should be avoided for paleotemperature reconstructions. Given the wide use of bivalve shells as environmental archives, similar studies on others species are required.
Tipo: | Text
Idioma: | Inglês

Identificador:

https://archimer.ifremer.fr/doc/00624/73622/73038.pdf

DOI:10.1016/j.ecss.2020.106777

https://archimer.ifremer.fr/doc/00624/73622/

Editor: | Elsevier BV
Formato: | application/pdf
Fonte: | Estuarine Coastal And Shelf Science (0272-7714) (Elsevier BV), 2020-08 , Vol. 240 , P. 106777 (8p.)

Fonte:

info:eu-repo/semantics/openAccess

restricted use