Authors:	Brosset, Cornélia Höche, Nils Witbaard, Rob Nishida, Kozue Shirai, Kotaro Mertz-Kraus, Regina Schöne, Bernd R.
Title:	Sr/Ca in shells of laboratory-grown bivalves (Arctica islandica) serves as a proxy for water temperature : implications for (paleo)environmental research?
Online publication date:	7-Nov-2023
Year of first publication:	2023
Language:	english
Abstract:	Seawater temperature is an essential quantity for paleoclimatological and paleoecological studies. A potential archive that can provide century-long, temporally well-constrained and high-resolution temperature proxy data is available in the form of bivalve shells. However, the number of well-accepted and robust temperature proxies contained in shells is limited to stable oxygen isotopes and carbonate clumped isotopes. Many studies have therefore investigated the possibility to reconstruct temperature from element/Ca properties, specifically Sr/Ca ratios in case of aragonitic shells. As demonstrated here, in agreement with thermodynamic expectations and the lattice strain model, shell Sr/Ca of laboratory-grown Arctica islandica specimens is strongly positively coupled to water temperature. If ultrastructure-related bias is mathematically eliminated, up to 75% of the variability in shell Sr/Ca data can be explained by water temperature. However, in field-grown specimens, this relationship is superimposed by other environmental variables that can hardly be quantified and mathematically eliminated. The explained variability of Sr/Ca is reduced to merely 26% and the prediction uncertainty too large for reliable temperature estimates. Most likely, the equable, less biased conditions in the laboratory resulted in the production of a more uniform shell ultrastructure (with larger and more elongated biomineral units) which in turn was associated with less variable Sr/Ca values and a stronger link to water temperature. Without a detailed understanding and quantification of the factors controlling ultrastructural variations in field-grown bivalves, it remains impossible to employ shell Sr/Ca of wild A. islandica specimens for precise temperature estimates, merely a qualitative temperature reconstruction seems feasible.
DDC:	540 Chemie 540 Chemistry and allied sciences 550 Geowissenschaften 550 Earth sciences 560 Paläontologie 560 Paleontology 570 Biowissenschaften 570 Life sciences 590 Tiere (Zoologie) 590 Zoological sciences
Institution:	Johannes Gutenberg-Universität Mainz
Department:	FB 09 Chemie, Pharmazie u. Geowissensch.
Place:	Mainz
ROR:	https://ror.org/023b0x485
DOI:	http://doi.org/10.25358/openscience-9648
Version:	Published version
Publication type:	Zeitschriftenaufsatz
Document type specification:	Scientific article
License:	CC BY
Information on rights of use:	https://creativecommons.org/licenses/by/4.0/
Journal:	Frontiers in Marine Science 10
Pages or article number:	1279164
Publisher:	Frontiers Media
Publisher place:	Lausanne
Issue date:	2023
ISSN:	2296-7745
Publisher DOI:	10.3389/fmars.2023.1279164
Appears in collections:	DFG-491381577-G