Interpreting environmental change using bivalve shell geochemistry
type: CreativeWork
description: To further our understanding of Earth’s climate beyond historical records, a number of paleoclimate proxies are used to infer how climate has changed throughout Earth’s history. Examined herein are two such geochemical proxies—the δ¹⁸O of the shell of the Australian mud or flat oyster, Ostrea angasi, and the Mg/Ca ratio of the shells of the Sydney Rock oyster, Saccostrea glomerata, and the common mussel, Mytilus galloprovincialis. The proxies were calibrated using in situ culturing experiments with modern specimens. Oysters and mussels were cultured for approximately one year in three locations representative of the broad distribution of the species along the east coast of Australia: Little Swanport, Tasmania (O. angasi, M. galloprovincialis); Pambula Lake, New South Wales (O. angasi, S. glomerata, M. galloprovincialis) and Moreton Bay, Queensland (S. glomerata). Temperature loggers were deployed with the specimens and water samples taken fortnightly. The O. angasi shells were sampled using a Merchantek microsampling system at the Vrije Universiteit Amsterdam and the University of Michigan, and δ¹⁸O was analysed via ICP-MS. The trace element ratios of S. glomerata shells were analysed via Laser Ablation ICP-MS at the Australian National University. The data from the Pambula Lake and Little Swanport O. angasi were combined to produce a regression relationship between temperature and δ¹⁸Oshell and δ¹⁸Owater. For S. glomerata, the Mg/Ca data from Pambula Lake and Moreton Bay were compiled to produce a mean Mg/Ca signal for the shells from each location. Linear regressions with temperature showed a significant difference in the S. glomerata Mg/Ca-temperature relationships for the two locations. This difference was not evident when the DMg-temperature relationship was calculated, indicating that the underlying salinity or water chemistry can impact upon the S. glomerata shell Mg/Ca. The Mg/Ca-temperature relationship within M. galloprovincialis shells from Pambula Lake a…
abstract: To further our understanding of Earth’s climate beyond historical records, a number of paleoclimate proxies are used to infer how climate has changed throughout Earth’s history. Examined herein are two such geochemical proxies—the δ¹⁸O of the shell of the Australian mud or flat oyster, Ostrea angasi, and the Mg/Ca ratio of the shells of the Sydney Rock oyster, Saccostrea glomerata, and the common mussel, Mytilus galloprovincialis. The proxies were calibrated using in situ culturing experiments with modern specimens. Oysters and mussels were cultured for approximately one year in three locations representative of the broad distribution of the species along the east coast of Australia: Little Swanport, Tasmania (O. angasi, M. galloprovincialis); Pambula Lake, New South Wales (O. angasi, S. glomerata, M. galloprovincialis) and Moreton Bay, Queensland (S. glomerata). Temperature loggers were deployed with the specimens and water samples taken fortnightly. The O. angasi shells were sampled using a Merchantek microsampling system at the Vrije Universiteit Amsterdam and the University of Michigan, and δ¹⁸O was analysed via ICP-MS. The trace element ratios of S. glomerata shells were analysed via Laser Ablation ICP-MS at the Australian National University. The data from the Pambula Lake and Little Swanport O. angasi were combined to produce a regression relationship between temperature and δ¹⁸Oshell and δ¹⁸Owater. For S. glomerata, the Mg/Ca data from Pambula Lake and Moreton Bay were compiled to produce a mean Mg/Ca signal for the shells from each location. Linear regressions with temperature showed a significant difference in the S. glomerata Mg/Ca-temperature relationships for the two locations. This difference was not evident when the DMg-temperature relationship was calculated, indicating that the underlying salinity or water chemistry can impact upon the S. glomerata shell Mg/Ca. The Mg/Ca-temperature relationship within M. galloprovincialis shells from Pambula Lake a…
author: Tynan, Sarah
language: en
keywords: sclerochronology, oysters, trace elements, stable isotopes, bivalve, geochemistry
date published: 2017
date modified: 2026-07-24T01:07:48Z
provider: Australian Catholic University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Australian Catholic University

PropertyValue
property ID: Handle
value: http://hdl.handle.net/1885/142556