Marine & Environmental Sciences Faculty Articles

Document Type

Article

Publication Date

1-19-2021

Publication Title

Geophysical Research Letters

Keywords

coral reef metabolism, dissolution, community calcification, Great Barrier Reef, calcium carbonate, ocean acidification

ISSN

1944-8007

Volume

48

First Page

e2020GL090811

Abstract

There are concerns that reefs will transition from net calcifying to net dissolving in the near future due to decreasing calcification and increasing dissolution rates. Here we present in situ rates of net ecosystem calcification (NEC) and net ecosystem production (NEP) on a coral reef flat using a slack-water approach. Up until dusk, the reef was net calcifying in most months but shifted to net dissolution in austral summer, coinciding with high respiration rates and a lower aragonite saturation state (Ωarag). The estimated sediment contribution to NEC ranged from 8 – 21 % during the day and 45 – 78 % at night, indicating that high rates of sediment dissolution may cause the transition to reef dissolution. This late afternoon seasonal transition to negative NEC may be an early warning sign of the reef shifting to a net dissolving state and may be occurring on other reefs.

Comments

The authors would like to thank Daniel Trnovsky, Jacob Yeo, Jessica Rickenberg, Marc Jordan, and Elisabeth Deschaseaux for assistance in the field. Bronte Tilbrook kindly provided the SeapHOx sensor for monitoring environmental data. We thank the staff at Heron Island Research Station. Research was carried out under the Great Barrier Reef Marine Park Authority Permit G1Q6/38438.1. An ARC Discovery Grant DP150102092 awarded to B.D.E. and K.G.S. provided funding for this research.

2020gl090811-sup-0001-text_si-s01.docx (18739 kB)
Supporting Information S1

ORCID ID

0000-0003-3556-7616

DOI

10.1029/2020GL090811

Available for download on Wednesday, August 25, 2021

Peer Reviewed

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