Istituto di Scienze Marine     
Trevisiol A., Bergamasco A., Montagna P., Sprovieri M., Taviani M. Antarctic seawater temperature evaluation based on stable isotope measurements on Adamussium colbecki shells: kinetic effects vs. isotopic equilibrium. In: Journal of Marine Systems, vol. 126 (Special Issue) pp. 43 - 55. Conference: 43rd Joint International Liege Colloquium on Ocean Dynamics / Geotraces-Bonus-GoodHope Meeting Location: Liege, BELGIUM Date: MAY 02-06, 2011 Sponsor(s): Geotraces Program; Bonus; GoodHope. ELSEVIER SCIENCE BV, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS, 2013.
A year-long controlled growth experiment of 60 specimens of the Antarctic bivalve Adamussium colbecki was conducted in Terra Nova Bay (Ross Sea) to evaluate its reliability as a suitable archive of water mass properties. Nine shells were sub-sampled for stable oxygen and carbon isotope analysis to study the inter and intra specimen variations. Slow-growing A. colbecki precipitate their calcitic shells close to the expected oxygen and carbon isotopic equilibrium, whereas the fast-growing individuals are strongly influenced by biogenetic and kinetic effects. The equation of Kim and O'Neil (1997) is considered a fair approximation for the delta O-18-temperature relationship in slow-growing individuals. The reconstructed temperature is closer to the mean experimental summer temperature than the annual one. This fact is interpreted as reflecting a possible winter decrease of shell growth, the salinity variation and the corrections for negative temperature on calibrating the delta O-18-temperature relationship. Our results support the hypothesis that A. colbecki might represent a good archive for encoding Antarctic Shelf water summer temperature information. Further improvements in adopting A. colbecki as a paleotemperature archive will require the evaluation of the seasonal variability in shell growth rate through culturing slow-growing A. colbecki individuals at near-freezing temperatures to calibrate a species-specific delta O-18-temperature equation. (c) 2012 Elsevier B.V. All rights reserved.
DOI: 10.1016/j.jmarsys.2012.10.012
Subject Adamussium colbecki; Bivalve; Ross Sea; Antarctic Shelf waters; Stable isotopes; Growth rate; Temperature proxy

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