Understanding the response of marine ecosystems to ocean-based carbon dioxide removal

Second Supervisor (External Lead): Dr Glen Wheeler

Lead Supervisor (DoS): Dr George Littlejohn

Third Supervisor: Professor Helen Findlay

Applications are invited for a 3.5 year PhD studentship with Marine Research Plymouth – a collaborative partnership between the University of Plymouth, the Plymouth Marine Laboratory and the Marine Biological Association. The studentship is due to start on 1 October 2025.

This project is one of three topics available for the studentship. We anticipate supporting one position, which will be allocated to the best combination of candidate and project as they emerge from interviews across the pool of available topics. Browse all available studentship topics .

Plymouth has been at the forefront of global marine research for more than a century, and today it is home to the largest concentration of marine researchers in the UK. Come and join our vibrant community of marine PhD students.

The development of ocean carbon dioxide removal (oCDR) technologies, aimed at helping oceans sequester atmospheric carbon dioxide to prevent excessive warming of our planet, have attracted substantial interest recently. Ocean alkalinity enhancement (OAE) is one such example, where the addition of finely ground mineral rocks to seawater represents an acceleration of natural weathering processes and causes carbon dioxide to be drawn down.

oCDR holds much promise for helping us achieve carbon budgets, but their impact on marine ecosystems remains poorly understood. Mineral additions cause localised hotspots of low carbon dioxide, which are temporary, but impact on the photosynthesis and growth of marine phytoplankton that support the entire marine food web. A better understanding of how oCDR influences different phytoplankton types is needed to assess the wider impact of these technologies on marine ecosystems.

The project will examine the impact of OAE on marine phytoplankton, testing the resilience of various species to episodes of low carbon dioxide. Identifying these groups will help us understand how, when and where oCDR technologies can be deployed. The student will have the opportunity to learn multiple experimental techniques, including the design and application of OAE approaches. Further techniques will include phytoplankton physiology, field sampling and advanced microscopy. Full training will be provided. The student will also be able to work with a range of international collaborators examining OAE.

Applicants should have a first or upper second class honours degree in an appropriate subject or a relevant Masters qualification. The project is suitable for candidates with experience in Marine Biology or Biological Sciences who have a strong interesting in marine ecosystems and their response to environmental change.

Non-native English speakers must have an IELTS Academic score of 6.5 or above (with no less than 5.5 in any element) or equivalent.

The studentship is supported for 3.5 years and includes full home tuition fees plus a stipend at the 2025/26 rate (to be confirmed; compare the 2024/25 UKRI rate of £19,237 per annum). The last 6 months of the four-year registration period is a self-funded ‘writing-up’ period. The studentship will only fully fund those applicants who are eligible for home fees with relevant qualifications. Applicants normally required to cover international fees will have to cover the difference between the home and the international tuition fee rates (to be confirmed; compare the 2024/25 rate of £13,244).

If you wish to discuss this project further informally, please contact Dr Glen Wheeler or Dr George Littlejohn .

Shortlisted candidates will be informed as soon as possible after the deadline, with interviews likely to take place in the second half of February. We regret that we may not be able to respond to all applications. Applicants who have not received a response within six weeks of the closing date should consider that their application has been unsuccessful on this occasion.