High spatio-temporal variability in Acroporidae settlement to inshore reefs of the Great Barrier Reef

PLoS One. 2019 Jan 30;14(1):e0209771. doi: 10.1371/journal.pone.0209771. eCollection 2019.

Abstract

Recovery of coral reefs after disturbance relies heavily on replenishment through successful larval settlement and their subsequent survival. As part of an integrated study to determine the potential effects of water quality changes on the resilience of inshore coral communities, scleractinian coral settlement was monitored between 2006 and 2012 at 12 reefs within the inshore Great Barrier Reef. Settlement patterns were only analysed for the family Acroporidae, which represented the majority (84%) of settled larvae. Settlement of Acroporidae to terracotta tiles averaged 0.11 cm-2, representing 34 ± 31.01 (mean ± SD) spat per tile, indicating an abundant supply of competent larvae to the study reefs. Settlement was highly variable among reefs and between years. Differences in settlement among locations partly corresponded to the local cover of adult Acroporidae, while substantial reductions in Acroporidae cover caused by tropical cyclones and floods resulted in a clear reduction in settlement. Much of the observed variability remained unexplained, although likely included variability in both connectivity to, and the fecundity of, adult Acroporidae. The responsiveness of settlement patterns to the decline in Acroporidae cover across all four regions indicates the importance of supply and connectivity, and the vulnerability towards region-wide disturbance. High spatial and temporal variability, in addition to the resource-intensive nature of sampling with settlement tiles, highlights the logistical difficulty of determining coral settlement over large spatial and temporal scales.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anthozoa / growth & development*
  • Anthozoa / metabolism
  • Australia
  • Conservation of Natural Resources / methods*
  • Coral Reefs
  • Larva
  • Natural Resources
  • Reproduction
  • Spatio-Temporal Analysis
  • Water Quality

Grants and funding

This study was carried out as part of a larger monitoring program on the Great Barrier Reef. The Reef Rescue Marine Monitoring Program (MMP) was developed by the Great Barrier Reef Marine Park Authority and funded by the Australian Government's Reef Rescue initiative. A summary of the MMP's overall goals and objectives, and a description of the sub-programs are available at http://www.gbrmpa.gov.au/about-the-reef/how-the-reefs-managed/science-and-research/our-monitoring-and-assessment-programs/reef-rescue-marine-monitoring-program and http://e-atlas.org.au/rrmmp. The Reef Rescue initiative had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.