Hot off the press! First evidence that elevated nutrients impacted the Holocene initiation of the Great Barrier Reef

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Modified from Sanborn et al., 2020 (Sedimentary Geology) and 2024 (Quaternary Science Reviews).

Please join me in congratulating GRG collaborator Dr Kelsey Sanborn and the team on publication of our new paper in the journal Quaternary Science Reviews.

Sanborn, K.L., Webster, J.M., Erler, D., Webb, G.E., Salas-Saavedra, M., Yokoyama, Y., The impact of elevated nutrients on the Holocene evolution of the Great Barrier Reef. Quaternary Science Reviews 332. https://doi.org/10.1016/j.quascirev.2024.108636

You can also read more about the work and its wider implications in the associated media release here.

Highlights

  • First record of δ15N isotopes and Ba/Ca ratios from well-dated early Holocene corals from the southern Great Barrier Reef.
  • Tests hypothesis that elevated nutrients negatively impacted reef development during the early Holocene.
  • Elevated δ15N and Ba/Ca coral values suggest increased terrestrially-sourced nutrient levels on the reef at the time.
  • REE+Y measurements on both corals and microbialites also imply increased terrestrial influence.
  • These conditions led to slower-growing, deeper and more sediment-tolerant coral early Holocene communities.

This paper represents a fundamental advance in our use of fossil reef cores to reconstruct paleowater quality, including the influx of nutrients and land-derived sediments and their impact on the Great Barrier Reef (ie. changes in paleoecology, vertical accretion rates etc).

Image credits: Geocoastal Research Group (GRG) & Trevor Graham

This paper is part of an ongoing collaborative program of research involving USYD, UQ, QUT, SCU and several international partners focused comparing changes in Holocene (and beyond) water quality, and other environmental parameters, with corresponding changes in reef responses (ecology, growth, bioerosion etc) in the Great Barrier Reef.  The goal being to establish the key environmental thresholds that have caused major changes to how the reef has evolved in the past to better inform future predictions.

Bravo to Kelsey and the team!

Cheers

Jody

#MarineScienceSydneyUni

Image credits: Geocoastal Research Group (GRG) & Trevor Graham

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