Lessons from the past: Deoxygenation and the
'dead-zones' of the ocean


The availability of oxygen in the ocean is fundamental for marine life. As the ocean warms with future climate change the amount (or solubility) of oxygen in seawater declines. Alongside ocean circulation becoming sluggish this leads to the expansion of the so-called ‘dead-zones’ of the ocean – the oxygen minimum zones (OMZs). But this has all happened before – over geological time oxygen concentrations in the oceans have fluctuated, the OMZs expanded and contracted, however we have very little understanding of such variability, the environmental drivers or the biogeochemical consequences, especially in a quantitative sense. We seek a highly motivated PhD candidate interested in contributing to a revolution in our understanding of changes in oceanic oxygen concentrations in the geological past, working on the development and application of novel proxies for seawater oxygenation. This project will further develop and ground-truth recently developed proxies (Hoogakker et al., 2015; Lu et al., 2016) with new modern and paleo-data to construct time-series seawater oxygen concentrations, including expansion and contraction of OMZs. These proxies are based on chemical analysis of foraminifera living in the water-column and deep-sea sediments, and the project will involve analysis of fresh and ancient specimens. The time-series developed will be crucial to Earth System Modelling examining future changes in ocean oxygenation, helping to provide greater clarity to IPCC-type predictions of future climate by understanding the past.

The student will be based at the Lyell Centre for Earth and Marine Science and Technology in Edinburgh within an active research group looking at marine biogeochemistry in both the modern ocean as well as the past. The Lyell Centre offers a dynamic and stimulating research environment enabled by the exciting collaborative research initiative between Heriot-Watt University and the British Geological Survey (BGS). The student will have the opportunity to spend time at the BGS Environmental Science Centre in Keyworth and participate in fieldwork.


  • Hoogakker, B.A.A., Elderfield, H., Schmiedl, G., McCave, I.N., Rickaby, R.E.M. Glacial-interglacial changes in bottom-water oxygen content on the Portuguese margin. Nat. Geosci. 8, 40-43 (2015).
  • Lu, Z., Hoogakker, B.A.A., Hillenbrand, C.-D., Zhou, X., E. Thomas, E., et al. . Oxygen depletion recorded in upper waters of the glacial Southern Ocean. Nat. Comm. 7, 11146 (2016).
  • Schmidtko, S., Stramma, L., Visbeck, M. Decline in global oceanic oxygen content during the past five decades. Nature 542, 335-229 (2017).

Funding Notes

This is a full scholarship which will cover tuition fees and provide an annual stipend of approximately £14,500 for the 36 month duration of the studentship. The funding is available to UK, EU and international students.


Applicants should have a first-class honours degree or a 2.1 honours degree plus Masters (or equivalent) in a relevant subject. Highly motivated applicants with a qualification in earth and ocean sciences, marine biology, biogeochemistry, and an interest in the advancement and application of foraminiferal proxies are particularly encouraged to apply. Scholarships will be awarded by competitive merit, taking into account the academic ability of the applicant.

How to Apply

Please complete our online application form by clicking "Apply Now" button below

Please select PhD programme Marine Biology and include the full project title, reference number and supervisor on your application form. You will also need to provide a CV, a supporting statement, a copy of your degree certificate and relevant transcripts and references from two academic sources. You must also provide proof of your ability in the English language (if English is not your mother tongue or if you have not already studied for a degree that was taught in English). We require an IELTS certificate showing an overall score of at least 6.5 with no component scoring less than 6.0 or a TOEFL certificate with a minimum score of 90 points.

Informal enquiries should be addressed to Dr Babette Hoogakker: b.hoogakker@hw.ac.uk


The closing date for applications is Friday 24th November. Interviews will be held in December 2017. The anticipated project start date is spring 2018.

posted: 06 October 2017     Please mention EARTHWORKS when responding to this advertisement.