Skip to main content
Article
Hysteresis Between Coral Reef Calcification and the Seawater Aragonite Saturation State
Geophysical Research Letters
  • Ashly McMahon, Southern Cross University - Lismore, Australia
  • Isaac R. Santos, Southern Cross University - Lismore, Australia
  • Tyler Cyronak, Southern Cross University - Lismore, Australia
  • Bradley D. Eyre, Southern Cross University - Lismore, Australia
Document Type
Article
Publication Date
8-1-2013
Keywords
  • Ocean acidification,
  • Permeable sediments,
  • Carbon dioxide,
  • Coastal waters,
  • Calcite,
  • Aragonite
Abstract

Some predictions of how ocean acidification (OA) will affect coral reefs assume a linear functional relationship between the ambient seawater aragonite saturation state (Ωa) and net ecosystem calcification (NEC). We quantified NEC in a healthy coral reef lagoon in the Great Barrier Reef during different times of the day. Our observations revealed a diel hysteresis pattern in the NEC versus Ωa relationship, with peak NEC rates occurring before the Ωa peak and relatively steady nighttime NEC in spite of variable Ωa. Net ecosystem production had stronger correlations with NEC than light, temperature, nutrients, pH, and Ωa. The observed hysteresis may represent an overlooked challenge for predicting the effects of OA on coral reefs. If widespread, the hysteresis could prevent the use of a linear extrapolation to determine critical Ωa threshold levels required to shift coral reefs from a net calcifying to a net dissolving state.

Comments

©2013. American Geophysical Union. All Rights Reserved.

Additional Comments
ARC grant #: DP110103638
ORCID ID
0000-0003-3556-7616
DOI
10.1002/grl.50802
Citation Information
Ashly McMahon, Isaac R. Santos, Tyler Cyronak and Bradley D. Eyre. "Hysteresis Between Coral Reef Calcification and the Seawater Aragonite Saturation State" Geophysical Research Letters Vol. 40 Iss. 17 (2013) p. 4675 - 4679 ISSN: 0094-8276
Available at: http://works.bepress.com/tyler-cyronak/20/