Is coral bleaching getting fatter?

Overview

The ecosystem services provided by coral reefs are worth over $100 billion annually and include coast line protection, tourism, food and medical derivatives. However, the health of the constituent corals can be significantly impacted by coral bleaching. Coral bleaching is the loss of symbiotic zooxanthellae (Symbiodiniaceae) from tropical corals and can be caused by stressors such as thermal perturbations, disease and freshwater runoff (Fig 1). Thermal perturbations are thought to be the most significant bleaching trigger and have been well documented in conjunction with major global bleaching events in 1998, 2002 & 2016/17. These mass bleaching events caused widespread coral death with catastrophic ecosystem and service provision impacts.

While we have an improving understanding of the external triggers of coral bleaching and the devastation bleaching can cause, the internal bleaching mechanism itself is still not fully understood. There is evidence that lipids may play a role in bleaching through their functions in energy allocation and transfer to the coral host (Baumann et al. 2014, Imbs et al. 2014), however, this may interact with other physiological and environmental triggers. In particular, differences in lipid and fatty acid metabolism and transfer may impart bleaching sensitivity or robustness in some coral-symbiont-microbe communities (Grottoli et al. 2017). Using laboratory and Caribbean-based field experiments, this project will assess the role and function of lipids and fatty acids in coral bleaching sensitivity, with a focus on between-species sensitivity and resilience.

Aim: This project will determine the roles of lipids in the coral bleaching process. This is important as it will enable a more robust understanding of coral bleaching and its precursors.

Click on an image to expand

Image Captions

Figure 1: Before and after widespread bleaching of a Samoan coral reef (Photo: The Ocean Agency / XL Catlin Seaview Survey)

Figure 2: The supervisory team collecting samples for laboratory analysis

Methodology

The scholar will have the opportunity to conduct field work in the Caribbean (Honduras and/or Dominica) (Fig. 2; diving is optional). The PhD will also involve laboratory work conducted at the University of Glasgow and the Lyell Centre. Field work will involve in situ sampling of corals and reef surveys during different bleaching phases. Laboratory analyses will involve organic biomarker assays, pulse chase experiments and subsequent interpretation of the data.

Project Timeline

Year 1

-Literature review and techniques training
-Field collection, processing, analysis (isotope and lipid), and synthesis of environmental and experimental samples/data

Year 2

-Field collection, pulse chase experiments
-Sample and data analysis and synthesis with current literature
-Dissemination of findings via discipline-specific conferences and peer-reviewed publications

Year 3

-Data analysis and synthesis with current literature
– Dissemination, publications and conference attendance

Year 3.5

-Thesis completion, dissemination, publications

Training
& Skills

The successful candidate will be fully trained in field identification and collection of samples, isotopic analysis, processing samples for lipid analysis in the Marine Global Change and Biomarkers for Environmental and Climate Change laboratories using GC-FID, GC-MS, GC-IRMS instruments for identification, quantification and compound-specific isotope analysis.

A full range of transferable skills training is accessible to the student through IAPETUS2 specific provision and the University of Glasgow. Example courses include:
• Media Training
• Insights to industry
• Leadership skills
• Conference skills (e.g., networking, poster and oral presentation skills)
• Grant writing
• CV workshop

Project support: The facilities and instrumentation available within the supervisors’ and CASE partner’s institutions provide a combination of leading laboratory, field and analytical capability and technical support that will be ideal for this proposed research, maximising PhD training from experts in the field.

Scholar support: The School of Geographical and Earth Sciences at the University of Glasgow (GES) has a large research student cohort that will provide peer-support throughout the research program. The scholar will participate in the annual post-graduate research conference within GES, providing an opportunity to present their research to postgraduates and staff within the School, and to also learn about the research conducted by their fellow postgraduate peers. All project supervisors are highly research-active; the scholar will interact with all members of their research groups, providing an opportunity to learn about other techniques and research areas which may be applicable to their research. Additionally, the supervisors are all based in research-active departments that span a broad range of ecological and environmental research, exposing the scholar to a range of other research areas. To facilitate this, the scholar will actively participate in the ‘Marine Global Change’ and ‘Biomarkers for Environmental and Climate Change’ groups in GES and the ‘Coastal Biogeochemistry’ group at the Lyell Centre. These group meetings provide opportunities to discuss cutting-edge topics in the field, review recent papers and to present current research plans to academics with a common research interest in an informal and supportive atmosphere.

The scholar will be encouraged to attend specialist courses that will directly contribute to the proposed project:
• The project involves a large component of isotopic and organic biomarker research and the scholar will be encouraged to attend relevant course throughout the PhD.
• This project will involve some field work, thus the scholar may attend a field first aid course in the first 6 months of the project.
• Analytical training will be provided by the supervisors and / or specialist technicians for each piece of instrumentation required for analyses.
• The project supervisors will also support and encourage the scholar’s attendance on transferable skills training such as data management, scientific writing and science communication. The Faculty of Science and Engineering at the University of Glasgow provides, for free, a large number of such courses, which are available throughout the PhD program.

References & further reading

Grottoli, A.G., Tchernov, D., and Winters, G. (2017). Physiological and Biogeochemical Responses of Super-Corals to Thermal Stress from the Northern Gulf of Aqaba, Red Sea. Frontiers in Marine Science. DO 10.3389/fmars.2017.00215

Imbs, A.B., Yakovleva, I.M., Dautova, T.N., Bui, L.H., and Jones, P. (2014). Diversity of fatty acid composition of symbiotic dinoflagellates in corals: Evidence for the transfer of host PUFAs to the symbionts. Phytochemistry 101, 76-82. https://doi.org/10.1016/j.phytochem.2014.02.012.

Baumann, J., Grottoli, A.G., Hughes, A.D., and Matsui, Y. (2014). Photoautotrophic and heterotrophic carbon in bleached and non-bleached coral lipid acquisition and storage. Journal of Experimental Marine Biology and Ecology 461, 469-478. https://doi.org/10.1016/j.jembe.2014.09.017

Further Information

Please contact Nick (nick.kamenos@glasgow.ac.uk) before applying

IAPETUS2 applications: to apply for this PhD please use the url: https://www.gla.ac.uk/study/applyonline/?CAREER=PGR&PLAN_CODES=CF18-7316

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