Project code



School of the Environment Geography and Geosciences

Start dates

October, February and April

Closing date


This project is now closed. The details below are for information purposes only. Please see the Earth and Environmental Sciences Postgraduate Research Degree page for further opportunities. 

This 3-year self-funded PhD will be based in the School of Earth and Environmental Sciences and will be supervised by Dr Sarah Reynolds, Dr Federica Ragazzola and Dr Michelle Hale.

The work on this project will:

  • assess the impact of climate change on nutrient resources in both the coastal and open ocean environment
  • simulate a multi-stressor environment (elevated temperature, OA, increase in nutrient inputs) of a temperate coastal setting in a future scenario
  • assess the impacts on nutrient biogeochemistry

Nutrients within the marine environment are involved in complex cycles, which maintain the biological community and influence atmospheric carbon dioxide concentrations. Anthropogenic-induced climate change is having a major impact on the world’s oceans. They are becoming warmer, sea levels are rising and waters are acidfiying too.

Studies have shown these changes are having an impact on marine ecosystems, but there has been little focus on the impact of climate change on the biogeochemical cycling of the nutrients, nitrogen and phosphorus.

Within the coastal and shelf sea environment, modern nutrient cycles are perturbed not only by enhanced warming and ocean acidification but also by increased anthropogenic inputs from both urban and agricultural run-off, as well as atmospheric nitrogen deposition.

However, in the isolated open ocean, which is often characterised by very low concentrations of nitrogen and phosphorous, inputs of anthropogenic-derived nutrients are limited to the atmospheric deposition of nitrogen only. Additionally, enhanced stratification from ocean warming would restrict the mixing of water masses, further reducing the supply of nutrients to the surface ocean. This perturbation of the nutrient cycles could lead to further phosphorus limitation in the oligotrophic oceans.

There is still much uncertainty into how these complex ecosystems will respond to such pressures and there has been little insight given to how the dynamics and cycling of how these vital nutrients will be impacted in the future.

The overall aim of this project is to assess the impact of climate change on nutrient resources in both the coastal and open ocean environment.

The successful applicant student will be involved in laboratory manipulations to simulate a multi-stressor environment (elevated temperature, OA, increase in nutrient inputs) of a temperate coastal setting in a future scenario and assess the impacts on nutrient biogeochemistry. Additionally, fieldwork in the Atlantic Ocean will explore further phosphorus limitation in an oligotrophic ocean and investigate the effects on nutrient resources.

The successful candidate will also gain extensive experience in the running of chemo-stats/bioassays and training in analytical techniques, with the opportunity for ship-board fieldwork. There will be access and opportunities in University of Portsmouth’s Graduate School Development Programme.

Fees and funding

Funding availability: Self-funded PhD students only.

PhD full-time and part-time courses are eligible for the UK Government Doctoral Loan (UK and EU students only).

Entry requirements

  • You'll need a good first degree from an internationally recognised university (minimum second class or equivalent, depending on your chosen course) or a Master’s degree in a relevant subject area.
  • In exceptional cases, we may consider equivalent professional experience and/or qualifications.
  • English language proficiency at a minimum of IELTS band 6.5 with no component score below 6.0.

We’d welcome applications from marine science graduates with a chemistry focus.

How to apply

Please contact Dr Sarah Reynolds ( to discuss your interest before you apply, quoting the project code.

When you are ready to apply, you can use our online application form and select ‘Geography, Earth and Environmental Sciences’ as the subject area. Make sure you submit a personal statement, proof of your degrees and grades, details of two referees, proof of your English language proficiency and an up-to-date CV.

Our ‘How to Apply’ page offers further guidance on the PhD application process.

Please note, to be considered for this self-funded PhD opportunity you must quote project code SEES4840219 when applying.

October start

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February start

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