A 45-year sub-annual reconstruction of seawater temperature in the Bay of Brest, France, using the shell oxygen isotope composition of the bivalve Glycymeris glycymeris

• Published in: The Holocene
• Main Authors: Featherstone, Amy M., Butler, Paul G., Schoene, Bernd R., Peharda, Melita, Thébault, Julien
• Other Authors: Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Bioscience Aarhus, University of Exeter, Institute of Geosciences Mainz, Johannes Gutenberg - Universität Mainz (JGU), Institute of Oceanography and Fisheries, European Project: 604802,EC:FP7:PEOPLE,FP7-PEOPLE-2013-ITN,ARAMACC(2013)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2020
• Subjects: ACL; climate-change; variability; marine; growth; stable isotopes; dog cockle; DISCOVERY; aragonite; UBO; pecten-maximus; sclerochronology; atlantic subpolar gyre; climate signals; eap; forecast; high-resolution proxy records; nao; northern-hemisphere temperatures; resolution; sclerochemistry; spg; temperature reconstruction; ARAMACC_FP7-PEOPLE-2013-ITN; anthro-bio; envir; North Atlantic
• Online Access: https://doi.org/10.1177/0959683619865592; https://hal.archives-ouvertes.fr/hal-02986934

International audience A reconstruction of sea surface temperature (SST) spanning 45 years (1966-2011) was developed from delta O-18 obtained from the aragonitic shells of Glycymeris glycymeris, collected from the Bay of Brest, France. Bivalve sampling was undertaken monthly between 2014 and 2015 using a dredge. In total, 401 live specimens and 243 articulated paired valves from dead specimens were collected, of which 24 individuals were used to reconstruct SST. Temperatures determined using the palaeotemperature equation of Royer et al. compared well with observed SST during the growing season between 1998 and 2010 (Pearson's correlation: p = 0.002, r = 0.760). Furthermore, a significant negative correlation was found between the reconstructed SST and the North Atlantic Subpolar Gyre (SPG) index (p = 0.001, r = -0.50), and a significant positive correlation was found with the East Atlantic Pattern (EAP) index when the reconstructed SST was lagged by 1 year (p = 0.002, r = 0.46). This led to the conclusion that EAP and SPG are major influences on SSTs in the Bay of Brest. As the SPG controls air temperature in Northern Europe and the EAP controls water temperature in Southern Europe, this suggests that the Bay of Brest is an interaction area between these two climate systems. As such, this locality is interesting as the delta O-18 of the shells can be used as a proxy for both the SPG and EAP, and temperature reconstructions can provide a unique insight into how these climate systems interacted prior to the instrumental era.