Next Article in Journal
DNA Barcoding and Taxonomic Challenges in Describing New Putative Species: Examples from Sootywing and Cloudywing Butterflies (Lepidoptera: Hesperiidae)
Previous Article in Journal
Recovering Plant Data for Guinea-Bissau: Implications for Biodiversity Knowledge of West Africa
Article Menu

Export Article

Open AccessArticle
Diversity 2018, 10(4), 110; https://doi.org/10.3390/d10040110

The Variable Influences of Sea Level, Sedimentation and Exposure on Holocene Reef Development over a Cross-Shelf Transect, Central Great Barrier Reef

1
School of Environment, The University of Auckland, Auckland 1010, New Zealand
2
Environmental Science and Management, College of Science and Engineering, James Cook University, Townsville 4811, Australia
3
TropWATER, James Cook University, Townsville 4811, Australia
4
Radiogenic Isotope Facility, School of Earth and Environmental Science, The University of Queensland, Brisbane 4072, Australia
5
Australian Research Centre for Human Evolution, Environmental Futures Research Institute, Griffith University, Nathan 4111, Australia
*
Author to whom correspondence should be addressed.
Received: 5 August 2018 / Revised: 25 September 2018 / Accepted: 4 October 2018 / Published: 11 October 2018
Full-Text   |   PDF [2103 KB, uploaded 11 October 2018]   |  

Abstract

Coral reefs globally are impacted by natural and anthropogenic stressors that are compounded by climate change. Understanding past reef responses to natural stressors (cyclones, sea-level change, freshwater inputs, and sedimentation) can provide important insights to further understand recent (within the past century) trends in coral cover and diversity. Here we use a compilation of recently published data to investigate the Holocene development of five fringing reefs that are located on a cross-shelf transect on the central Great Barrier Reef, and that are exposed to varying degrees of natural and anthropogenic sedimentation, storm exposure, and Holocene sea-level change. Forty-two reef cores collected using a combination of manual percussion coring and hydraulic drilling techniques, were analysed and dated using uranium-thorium methods. The chronostratigraphic records of reef development established using 105 recently published radiometric ages and seven new uranium-thorium ages from the reef cores and fossil microatolls preserved across the reef flats were compared to investigate cross-shelf variations in reef development. This is the first study to conduct an internal investigation of reef framework across an inshore–offshore gradient to examine the varying levels of influence of sedimentation, sea level and cyclones. Our observations from the central Great Barrier Reef show that reefs furthest offshore from the mainland coast were typically initiated earliest after the post-glacial marine transgression. Reef flat size, morphology, and growth style varied according to constraints placed on reef development by the composition, depth, shape, and relief of the underlying substrate. We establish that terrigenous sedimentation had a marked effect on the development of inshore reefs closest to the mainland (within 10 km of the mainland coast). Periods of relatively high terrigenous sedimentation correspond with enhanced reef accretion rates, and also resulted in a superior record of palaeo-ecological coral composition (i.e., better preservation) at inshore sites. In contrast, mid-Holocene cyclones played a seemingly more important role in the development of reefs >10 km from the mainland; although cyclones clearly affect reefs closer inshore, their geomorphology is affected by a range of controlling factors. Insights provided by these five Holocene reef chronostratigraphies provide useful baseline understanding of reef condition and growth along a cross-shelf transect where the reefs are exposed to variable stressors. View Full-Text
Keywords: Great Barrier Reef; chronostratigraphy; Holocene; reef development; sedimentation; cyclone; U-Th dating; cross-shelf Great Barrier Reef; chronostratigraphy; Holocene; reef development; sedimentation; cyclone; U-Th dating; cross-shelf
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

Supplementary material

SciFeed

Share & Cite This Article

MDPI and ACS Style

Ryan, E.J.; Smithers, S.G.; Lewis, S.E.; Clark, T.R.; Zhao, J.-X. The Variable Influences of Sea Level, Sedimentation and Exposure on Holocene Reef Development over a Cross-Shelf Transect, Central Great Barrier Reef. Diversity 2018, 10, 110.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Diversity EISSN 1424-2818 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top