Coral Reefs

, Volume 35, Issue 1, pp 155–167

Tectonic subsidence provides insight into possible coral reef futures under rapid sea-level rise

  • Megan I. Saunders
  • Simon Albert
  • Chris M. Roelfsema
  • Javier X. Leon
  • Colin D. Woodroffe
  • Stuart R. Phinn
  • Peter J. Mumby
Report

DOI: 10.1007/s00338-015-1365-0

Cite this article as:
Saunders, M.I., Albert, S., Roelfsema, C.M. et al. Coral Reefs (2016) 35: 155. doi:10.1007/s00338-015-1365-0

Abstract

Sea-level rise will change environmental conditions on coral reef flats, which comprise extensive habitats in shallow tropical seas and support a wealth of ecosystem services. Rapid relative sea-level rise of 0.6 m over a relatively pristine coral reef in Solomon Islands, caused by a subduction earthquake in April 2007, generated a unique opportunity to examine in situ coral reef response to relative sea-level rise of the magnitude (but not the rate) anticipated by 2100. Extent of live coral was measured from satellite imagery in 2003, 2006, 2009 and 2012. Ecological data were obtained from microatolls and ecological surveys in May 2013. The reef was sampled at 12 locations where dense live hard coral remained absent, remained present or changed from absent to present following subsidence. Ecological data (substratum depth, live coral canopy depth, coral canopy height, substratum suitability, recruitment, diversity and Acropora presence) were measured at each location to identify factors associated with coral response to relative sea-level rise. Vertical and horizontal proliferation of coral occurred following subsidence. Lateral expansion of live coral, accomplished primarily by branching Acropora spp., resulted in lower diversity in regions which changed composition from pavement to dense live coral following subsidence. Of the ecological factors measured, biotic factors were more influential than abiotic factors; species identity was the most important factor in determining which regions of the reef responded to rapid sea-level rise. On relatively pristine reef flats under present climatic conditions, rapid relative sea-level rise generated an opportunity for hard coral to proliferate. However, the species assemblage of the existing reef was important in determining response to sea-level change, by providing previously bare substrate with a source of new coral colonies. Degraded reefs with altered species composition and slower coral growth rates may be less able to respond to climate change-induced sea-level changes.

Keywords

Sea-level rise Subsidence Species identity Species diversity Coral reef flat Subduction earthquake 

Supplementary material

338_2015_1365_MOESM1_ESM.tif (1.2 mb)
Fig. S1Histograms of frequency of occurrence of substrate depth, coral canopy depth and canopy height (cm) at locations in three categories—corals absent in satellite imagery both before and after subsidence (Absent), corals absent before and present after subsidence (Change) and corals present both before and after subsidence (Present)—on the reef flat at Kundu Kundu Island, Roviana, Solomon Islands, measured in May 2013. Dashed vertical lines indicate 60 cm depth relative to mean low water springs, which was the water level prior to April 2007 when an earthquake caused 60 cm tectonic subsidence. Prior to 2007, substrate or coral canopy to the left of the dashed lines would have been exposed at low tide (TIFF 1258 kb)
338_2015_1365_MOESM2_ESM.docx (13 kb)
Supplementary material 2 (DOCX 13 kb)
338_2015_1365_MOESM3_ESM.docx (31 kb)
Supplementary material 3 (DOCX 31 kb)
338_2015_1365_MOESM4_ESM.docx (14 kb)
Supplementary material 4 (DOCX 14 kb)
338_2015_1365_MOESM5_ESM.docx (14 kb)
Supplementary material 5 (DOCX 14 kb)
338_2015_1365_MOESM6_ESM.docx (29 kb)
Supplementary material 6 (DOCX 28 kb)

Copyright information

© Springer-Verlag Berlin Heidelberg 2015

Authors and Affiliations

  • Megan I. Saunders
    • 1
    • 2
  • Simon Albert
    • 3
  • Chris M. Roelfsema
    • 4
  • Javier X. Leon
    • 1
    • 4
    • 5
  • Colin D. Woodroffe
    • 6
  • Stuart R. Phinn
    • 1
    • 4
  • Peter J. Mumby
    • 1
    • 2
  1. 1.The Global Change InstituteThe University of QueenslandSt LuciaAustralia
  2. 2.Marine Spatial Ecology Lab and ARC Centre of Excellence for Reef Studies, School of Biological SciencesThe University of QueenslandSt LuciaAustralia
  3. 3.School of Civil EngineeringThe University of QueenslandSt LuciaAustralia
  4. 4.School of Geography, Planning and Environmental ManagementThe University of QueenslandSt LuciaAustralia
  5. 5.School of Science and EngineeringUniversity of the Sunshine CoastMaroochydore DCAustralia
  6. 6.School of Earth and Environmental SciencesUniversity of WollongongWollongongAustralia

Personalised recommendations