Giant bivalves (Tridacna gigas) as recorders of ENSO variability

Kevin Welsh, Mary Elliot, Alexander Tudhope, Bridget Ayling, John Chappell

Research output: Contribution to journalArticlepeer-review

Abstract

We compare monthly resolved oxygen isotope records derived from a giant bivalve shell, Tridacna gigas and massive Parkes corals collected along the northern coast of Papua New Guinea. This intercomparison study demonstrates that delta O-18 profiles obtained from these different aragonite-secreting organisms collected from within a 30 km range are correlated in great detail and record the timing and amplitude of seasonal and interannual (ENSO-related) variations in sea surface temperature (SST) and water isotopic composition which is closely related to rainfall. Furthermore, the T. gigas record is shown to be close to isotopic equilibrium with the local sea-water, in contrast to the corals which are approximately - 4 parts per thousand offset. These results reveal that living and fossil T. gigas clam shells have the potential to yield reliable records of past changes in seasonality and ENSO variability, as well as mean climate conditions. In particular, since the non-porous shells are generally more resistant to diagenesis than coral skeletons, they may provide robust estimates of past tropical climate for periods and locations where unaltered corals are absent. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.

Original languageEnglish
Pages (from-to)266-270
Number of pages5
JournalEarth and Planetary Science Letters
Volume307
Issue number3-4
DOIs
Publication statusPublished - 15 Jul 2011

Keywords

  • ENSO
  • bivalves
  • corals
  • oxygen isotopes
  • PAPUA-NEW-GUINEA
  • STABLE-ISOTOPES
  • SCLEROCHRONOLOGICAL RECORDS
  • TEMPERATURE VARIABILITY
  • SOUTHERN-OSCILLATION
  • REEF ENVIRONMENT
  • OXYGEN ISOTOPES
  • EL-NINO
  • PACIFIC
  • SHELLS

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