Friday, June 25, 2021

PhD Student

Funded PhD Studentship

Ocean deoxygenation effects on pelagic shark behaviour and consequences for conservation

The Marine Biological Association (MBA) invites applications for a PhD Studentship working within the OCEAN DEOXYFISH project (Ocean deoxygenation effects on threatened top predators: New understanding and predictions from novel bio-logging instruments and data). OCEAN DEOXYFISH is a recently funded European Research Council (ERC) Advanced Grant (€3.11M) award to Prof David Sims, an MBA Senior Research Fellow.

The PhD Studentship offers the opportunity to work on a high-profile international project under the guidance of a leading research team from six countries (UK, Portugal, Cabo Verde, Ireland, Australia, Japan) and linking with the Global Shark Movement Project (, a research collaboration of 150 scientists from 26 countries. The successful candidate will be based at the MBA Laboratory in Plymouth, UK, with fieldwork at sea in the UK, Portugal and Cabo Verde.

The supervisory team includes Prof David Sims (MBA/University of Southampton), Dr Marisa Vedor and Dr Nuno Queiroz (CIBIO/Universidade do Porto) and members of the OCEAN DEOXYFISH team. The successful candidate will be registered at the University of Southampton in the Graduate School of the National Oceanography Centre Southampton (GSNOCS). The University of Southampton is a member of the Russell Group and ranked in the world’s top 100 Universities.


OCEAN DEOXYFISH focuses on understanding the effects of ocean deoxygenation on marine top predators. Climate-driven reductions in dissolved oxygen (DO) of the global ocean interior (ocean deoxygenation) is leading to expansion of permanent oxygen minimum zones (OMZ) that comprise about 7% of ocean volume. Impacts on marine animal distributions and abundance may be particularly significant for high-oxygen-demand top predators, such as warm-bodied tunas and sharks, by reducing habitat volumes as OMZs expand (habitat compression) and concentrating fish further in surface waters where they become more vulnerable to fisheries. But predictions of how exploited oceanic fish actually respond to OMZ expansions are not based on mechanistic understandings, principally because direct measurements of oxygen tolerances and associated metabolic costs have not been determined. OCEAN DEOXYFISH will bring about a step change in understanding of OMZ impacts on oceanic ecology by applying the research team’s existing expertise in animal movement studies and by developing new biologging technologies and in situ physiology for measuring oxygen tolerances and metabolism directly in free-living fish.

OCEAN DEOXYFISH will enable major unknowns to be addressed concerning how oceanic fish respond physiologically and behaviourally to hypoxia, the role of OMZs in upper-trophic-level ecology, how oceanic fish habitats change with predicted OMZ expansion, and whether this will increase fish vulnerability to fishing gear. Objectives will be achieved through linked field, experimental and modelling studies. By focusing on key processes underlying fish responses to DO in situ, new modelling approaches will establish effects of future warming and OMZ shoaling on fish niches and determine how these shift distributions and alter capture risk by fisheries. The project represents a discipline-spanning approach linking physiology to ecology and oceanography, with wide-ranging outcomes for understanding global biotic responses to warming and ocean deoxygenation with direct relevance to sustainable fisheries and species conservation.

PhD Studentship details

The aim of the PhD will be to understand how deoxygenating environments affect oceanic shark space use and behaviour and how this may alter vulnerability to fisheries. The research will use newly developed bio-logging tags to record the movements, behaviour and environment of pelagic sharks in normoxic and hypoxic areas. Key questions include do pelagic sharks utilise low DO environments such as OMZs? Why do they? What are the tolerance limits? What are the environmental drivers of vertical niche? Are there species differences linked to physiology? How will space use in OMZs change in the future? Will this increase sharks’ vulnerability to fisheries?

Proposed objectives of the PhD research are to (1) determine the longer term movement patterns of pelagic sharks across high and low DO environments using satellite and archival telemetry, (2) monitor the short-term behavioural responses (dive depths; body movements; prey encounter) of sharks to low DO environments using newly developed bio-logging tags, (3) quantify biophysical habitat preferences and test the habitat compression hypothesis directly, (4) determine the impact of biophysical habitat changes on fishery catch rates of sharks above OMZs, and (5) predict the future habitat availability under climate-driven OMZ expansion and its implications for shark vulnerability to fishing. The successful candidate will be encouraged and supported to pursue these and related questions within the framework of the OCEAN DEOXYFISH project. The research will also involve the testing/deployment of new biologging tools (fin-mounted DO, pop-up DO and Trident V2 smart tags).

Essential requirements for the studentship would ideally include prior experience of shark research, knowledge of bio-logging technologies and their applications in animal movement ecology, experience in spatial statistical analysis, environmental modelling, and the ability to work with large movement/behaviour and environmental datasets. Programming skills (e.g. R, C#) would also be desirable. All necessary training will be provided by the supervisory team and the 16-member OCEAN DEOXYFISH research team.

Entry Requirements and Funding

Applicants should have or expect to obtain at least an Upper Second class (2.1) UK Honours degree in Marine Biology, Biological Sciences or related biological discipline, or the equivalent qualification obtained outside the UK. Previous research experience relevant to this project is also highly desirable.

The PhD project is funded for 3.5 years. Funding for UK applicants provides full Home Tuition Fees and a stipend of £15,609 tax-free per annum (the level for 2021/22). The funding available for this studentship covers Home Tuition Fees but not full Overseas Tuition Fees of international students. The University of Southampton postgraduate tuition fee information is here. Further details about the qualification for Home Tuition Fees is available from GSNOCS here. A research training support grant, currently £2,200 per annum, is also available in addition to the funding support provided by the ERC OCEAN DEOXYFISH project for lab consumables, fieldwork and overseas travel and subsistence. This position is only open to those applicants eligible to live and work in the UK.

For further information, please contact Prof David Sims (


The Marine Biological Association ( is an independent research institute carrying out leading-edge research in fundamental and strategic areas of marine biology.  As one of the world’s longest running learned societies (founded in 1884), the MBA is dedicated to promoting research into our oceans and the life that they support. Many eminent scientists, including twelve Nobel Prize winners, have conducted their research at the MBA’s Citadel Hill laboratory in Plymouth, UK. With our Royal Charter and over 1,900 members in 40+ countries worldwide, we have the mandate to provide an authoritative and independent voice for the international marine biological community.

Equal Opportunities

We are committed to equality of opportunity and applications from individuals are encouraged regardless of age, disability, sex, gender reassignment, sexual orientation, pregnancy and maternity, race, religion or belief and marriage and civil partnerships.

How to Apply:

To apply please send a covering letter and full CV with details of 2 academic referees to

The covering letter should:

  • outline your previous and most relevant experience
  • explain why you are right for this PhD project

Please also submit evidence of proficiency in English if English is not your first language.

Closing date:                                                          Friday, 25th June 2021

Interviews will take place the week of                 5th July 2021

Recent relevant papers by the Research Team:

Vedor, M., Queiroz, N., Mucientes, G., Couto, A., da Costa, I., dos Santos, A.M., Vandeperre, F., Afonso, P., Fontes, J., Rosa, R., Humphries, N.E., Sims, D.W. (2021) Climate-driven deoxygenation elevates fishing vulnerability for the ocean’s widest ranging shark. eLife 10, e62508.

Sims, D.W. (2019) Chapter 8.9 The significance of ocean deoxygenation for elasmobranchs. In Ocean Deoxygenation – Everyone’s Problem: Causes, Impacts, Consequences and Solutions. (Laffoley, D., & Baxter, J.M., eds), p. 451 – 468. Gland, Switzerland: IUCN.

Queiroz, N., Humphries, N.E., Couto, A., Vedor, M., et al., Sims, D.W. (2019) Global spatial risk assessment of sharks under the footprint of fisheries. Nature 572, 461-466.

Sequeira, A.M.M., Rodriguez, J., Eguíluz, V., Harcourt, R., Hindell, M., Sims, D.W., et al. (2018) Convergence of marine megafauna movement patterns in coastal and open oceans. PNAS 115, 3072-3077.

Queiroz, N., Humphries, N.E., Mucientes, G.R., Hammerschlag, N., Lima, F., Scales, K., Miller, P.I., Sousa, L.L., Seabra, R., Sims, D.W. (2016) Ocean-wide tracking of pelagic sharks reveals extent of overlap with longline fishing hotspots. PNAS 113, 1582-1587.