Hysteresis between coral reef calcification and the seawater aragonite saturation state

Ashly McMahon, Isaac R. Santos, Tyler Cyronak, Bradley D. Eyre

Research output: Contribution to journalArticlepeer-review

61 Scopus citations

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. Key Points Non-linear relationship between the aragonite saturation and calcification Production drives both calcification and the aragonite saturation state Predicting the effects of ocean acidification may be more complex than thought

Original languageEnglish
Pages (from-to)4675-4679
Number of pages5
JournalGeophysical Research Letters
Volume40
Issue number17
DOIs
StatePublished - Sep 16 2013

Scopus Subject Areas

  • Geophysics
  • General Earth and Planetary Sciences

Keywords

  • aragonite
  • calcite
  • carbon dioxide
  • coastal waters
  • ocean acidification
  • permeable sediments

Fingerprint

Dive into the research topics of 'Hysteresis between coral reef calcification and the seawater aragonite saturation state'. Together they form a unique fingerprint.

Cite this