Project highlights
- Develop multi-century long reconstruction of sea surface temperature and salinity from coral core geochemistry
- Access to unique long coral cores from massive colonies dating back to the 1500’s from the Great Barrier Reef and the Coral Sea Marine Park
- Assess historical thermal stress and ocean salinity variability and compare to coral growth parameters to test for adaptive capacity of corals to deal with chronic and acute stress events
Overview
The increasing frequency and duration of marine heatwaves associated with mean ocean warming in response to climate change (Oliver et al. 2018) has led to unprecedented instances of mass coral bleaching and mortality globally (Hughes et al. 2018). On the Great Barrier Reef and neighbouring Coral Sea Marine Parks (hereafter GBRMP & CSMP), four mass bleaching events over the past six years have led to a major reorganisation of coral communities (Harrison et al., 2019).
Recent evidence from short cores of massive reef building corals (Porites sp.) in the GBRMP & CSMP indicate some corals have learnt to better cope with these events by acclimating to higher temperatures (DeCarlo et al. 2019). Meanwhile, experimental studies in isolated reefs in the CSMP show that the higher frequency of mild marine heatwaves is selecting for colonies with higher temperature thresholds (Marzonie et al. 2022). However, accurate measures of mean and summer sea surface temperature (SST) over both ecological and evolutionary time scales are necessary to measure the potential for acclimation and adaptation to mitigate the effects of climate change on coral reefs. Most importantly, we lack an understanding of the multi-centennial historical thermal stress exposure at high enough temporal resolution (Hendy et al., 2002; Calvo et al., 2007; Zinke et al., 2023) across those vast reef systems at the reef-scale and at the living depth of the coral colonies (DeCarlo et al., 2019; DeCarlo, 2020).
This project will vastly expand our understanding of historical heat stress exposure of massive Porites sp. corals at depth of calcification extending the instrumental record by over six centuries in the iconic coral reef ecosystems of the Great Barrier Reef and Coral Sea Marine Park by developing monthly and annual coral geochemical reconstructions of sea surface temperature (SST) and X-ray based calcification at climate warming hotspot locations along a strong longitudinal heat stress exposure gradient. We will pair the historical thermal stress exposure and growth parameter reconstruction with stable isotope analysis of the same corals to reconstruct ocean salinity (e.g. Zinke et al., 2023).
Figure 1: A) Number of degree heating weeks (DHW) exceeding 8°C (extreme events) across the Great Barrier Reef (GBR) and Coral Sea Marine Park between 1985 and 2020. Location of coral cores. B) Maximum DHW across the GBR and Coral Sea since 1982.
Host
University of LeicesterTheme
- Climate and Environmental Sustainability
- Organisms and Ecosystems
Supervisors
Project investigator
- Prof. Jens Zinke, University of Leicester ([email protected])
Co-investigators
- Dr. Arnoud Boom, University of Leicester ([email protected])
- Prof. Gavin Foster, University of Southampton ([email protected])
- Dr. Hugo Harrison. University of Bristol
- Dr. Neal Cantin, AIMS, Australia
How to apply
- Each host has a slightly different application process.
Find out how to apply for this studentship. - All applications must include the CENTA application form. Choose your application route
Methodology
The coral cores and part of the coral tissue samples that we propose to study were already collected and dated with densitometry/CT-scanning by the Co-I’s and our CASE partner at no cost to NERC in collaboration with the Australian Institute of Marine Science (PI is Adjunct at AIMS) (DeCarlo et al., 2019; Harrison et al., 2019). We will develop annually resolved proxy records of changes in sea surface temperature (SST: (Sr/Ca; U/Ca; Sr-U; Li/Mg) and salinity (oxygen isotopes) from GBR and central Coral Sea coral cores using ICP-MS (funded by Foster lab at the Univ. Of Southampton) and stable isotope geochemistry (at UoL). We will assess changes in coral health through time by using available coral growth parameters on all cores and how recent 21st century changes sit within the long-term memory of thermal stress across the selected reef systems.
Training and skills
DRs will be awarded CENTA Training Credits (CTCs) for participation in CENTA-provided and ‘free choice’ external training. One CTC can be earned per 3 hours training, and DRs must accrue 100 CTCs across the three and a half years of their PhD.
The PhD student will receive extensive training in ICP-MS and stable isotope geochemistry from established international leaders in the field of coral core geochemistry. The study will include training in statistical data analysis and collaborations with climate scientists from the NCEO. Furthermore, the project will involve collaborations with Australian partners at the Australian Institute of Marine Science (AIMS).
Partners and collaboration
Prof. Gavin Foster is a leader in trace element geochemistry on marine carbonate including foraminifera and corals. Prof. Foster leads an advanced geochemical facility with a variety of instrumentation. He leads an EU Horizon Advanced Grant project with a number of PhDs and postdocs focused on coral skeletal geochemistry.
*Our CASE partner is the Australian Institute of Marine Science (AIMS) in Townsville, Queensland, Australia. Dr. Neal Cantin is our partner at AIMS, he leads the Australian coral core archive. PI Zinke is an Adjunct Senior Scientists at AIMS and was previously employed by AIMS between 2011-2015.
Further details
For any enquiries related to this project please contact Prof. Jens Zinke, University of Leicester ([email protected]).
To apply to this project:
- You must include a CENTA studentship application form, downloadable from: CENTA Studentship Application Form 2025.
- You must include a CV with the names of at least two referees (preferably three) who can comment on your academic abilities.
- Please submit your application and complete the host institution application process via: CENTA PhD Studentships | Postgraduate research | University of Leicester. Please scroll to the bottom of the page and click on the “Apply Now” button. The “How to apply” tab at the bottom of the page gives instructions on how to submit your completed CENTA Studentship Application Form 2025, your CV and your other supporting documents to your University of Leicester application. Please quote CENTA 2025-L21 when completing the application form.
Applications must be submitted by 23:59 GMT on Wednesday 8th January 2025.
Possible timeline
Year 1
Literature study month 1-6, project proposal and literature review as part of 9-month probation report which will feed into Introductory chapter of the thesis; training in geochemistry.
Year 2
Analysis of trace elements and stable isotopes at UoL and UoS laboratories; data acquisition and interpretation; familiarize with observational climate data; learn statistical methods; conference presentation of first results; write up results for Data Chapter 1.
Year 3
Synthesis of geochemical analytical results; refinement of thermal stress and salinity variability history at the selected core location; climate and oceanographic interpretation; write up results for Data Chapters 2 and 3 focussing on long-term variability and thermal stress events.
Further reading
Journal:
Calvo E, Marshall JF, Pelejero C et al. (2007) Interdecadal climate variability in the Coral Sea since 1708
A.D. Palaeogeography Palaeoclimatology Palaeoecology 248: 190–201.
DeCarlo T, Cohen AL, Wong GTF, Davis KA, Lohmann P, Soong K. (2017) Mass coral mortality under local amplification of 2C ocean warming. Scientific Reports 7:44586, doi:10.1038/srep44586.
DeCarlo TM, Harrison HB, Gajdzik L, Alaguarda D, Rodolfo-Metalpa R, D’Olivo J, Liu G, Patalwala D, McCulloch MT (2019) Acclimatization of massive reef-building corals to consecutive heatwaves. Proc. R. Soc. B286: 20190235. http://dx.doi.org/10.1098/rspb.2019.0235D
DeCarlo TM. (2020) Treating coral bleaching as weather: a framework to validate and optimize prediction skill. PeerJ 8:e9449 http://doi.org/10.7717/peerj.9449
D’Olivo JP, et al. (2018) A universal multi-trace element calibration for reconstructing sea surface temperatures from long-lived Porites corals: Removing ‘vital-effects’. Geoch. et Cosmoch. Acta 239, 109–135, https://doi.org/10.1016/j.gca.2018.07.035
Harrison HB, lvarez-Noriega M, Baird AH et al. (2019) Back-to-back coral bleaching events on isolated
atolls in the Coral Sea. Coral Reefs 38: 713–719.
Hendy EJ, Gagan MK, Alibert CA et al. (2002) Abrupt decrease in tropical Pacific sea surface salinity at end of Little Ice Age. Science 295: 1511–1514.
Marzonie, M. R. et al. (2022) The effects of marine heatwaves on acute heat tolerance in Corals. Global Change Biology, 1-13, https://onlinelibrary.wiley.com/doi/epdf/10.1111/gcb.16473
Zinke, J et al. (2023) North Flinders Reef (Coral Sea, Australia) Porites sp. corals as a candidate Global Boundary Stratotype Section and Point for the Anthropocene Series. The Anthropocene Review, 1-24, doi:10.1177/20530196221142.