Mg2+ and Ca2+ variability in seawater and the impact on marine calcifiers

BALTHASAR_P25ARIES

Mg2+ and Ca2+ variability in seawater and the impact on marine calcifiers

BALTHASAR_P25ARIES

Project Description

Supervisors

Dr Uwe Balthasar, School of Geography, Earth and Environmental Sciences (SoGEES), University of Plymouth – contact me

Dr Vassilis Kitidis, Plymouth Marine Laboratory

Dr Simon Ussher, University of Plymouth, SoGEES

Dr Tracy Aze, University of Plymouth, SoBMS

 

Scientific background

The natural weathering of calcium and magnesium rich minerals and rocks over geological time scales, controls the bulk chemical composition and pH of seawater and influenced the ecological success of marine calcifiers over millions of years [1-2]. The recent global development of ocean alkalinity enhancement (OAE), a carbon dioxide removal (CDR) method by which rock powders are added to seawater [3], has the potential to dramatically accelerate the changes to calcium and magnesium in coastal seas with possibly significant impacts on marine calcifiers [4]. To assess these possible impacts, we need to improve our understanding of the natural variability of the concentrations of calcium and magnesium in seawater [5] and how expected changes of these will impact marine calcifiers. The successful candidate for this project will work in the natural laboratory of Plymouth Sound to establish the first baseline of the natural variability of magnesium and calcium over ecological time scales. The results will help to mitigate the environmental impact of OAE.

Research methodology

This studentship will take advantage of world leading research vessels and facilities at the Western Channel Observatory and the University of Plymouth (UoP). Water samples from Plymouth Sound will be regularly sampled and analysed for Mg2+, Ca2+, pH, DIC, alkalinity, and salinity at the Plymouth Marine Laboratory and the UoP. Alongside this, bivalves will be cultured at the aquaculture facilities at the UoP at various Mg/Ca ratios and analysed for oxygen consumption, tissue growth and shell secretion.

Training

You will receive training in oceanographic surveys, marine sampling, sensor deployment, and the analysis of dissolved inorganic carbon and alkalinity, marine aquaculture, electron microscopy, and to work in ISO 9001 certified laboratories. You will gain expertise in analytical techniques for elemental analysis such as Inductively Coupled Plasma- Atomic Emission Spectroscopy, and data analysis and programming skills (e.g. Python, R, Matlab).

Person specification

Suited for applicants with a degree in an Earth, environmental, or biological science subject and a passion for multidisciplinary environmental and biological research.

Acceptable first degree subjects: Earth, environmental, or biological science

References

  • Balthasar, U. & Cusack, M., 2015. Aragonite-Calcite seas – Quantifying the gray area. Geology, 43(2), 99-102; https://doi.org/10.1130/G36293.1
  • Eichenseer, K., Balthasar, U., Smart, C., Stander, J., Haaga, K., and Kiessling, W., 2019. Jurassic shift from abiotic to biotic control on marine ecological success. Nature Geoscience, 12, 638–642; https://doi.org/10.1038/s41561-019-0392-9.
  • Kitidis, V., et al., 2024. Magnesium hydroxide addition reduces aqueous carbon dioxide in wastewater discharged to the ocean. Communications Earth & Environment, 5, 354; https://www.nature.com/articles/s43247-024-01506-4
  • Ries, J. B., 2010, Review: geological and experimental evidence for secular variation in seawater Mg/Ca (calcite-aragonite seas) and its effects on marine biological calcification. Biogeosciences, 7, 2795–2849; www.biogeosciences.net/7/2795/2010
  • Lebrato, M., et al., 2020, Global variability in seawater Mg:Ca and Sr:Ca ratios in the modern ocean. PNAS, 117 (36), 22281–22292; www.pnas.org/cgi/doi/10.1073/pnas.1918943117

Key Information

  • This studentship has been shortlisted for funding under the UKRI NERC DLA funding scheme and will commence on 1 October 2025. The closing date for applications is 23:59 on 8th January 2025.
  • Successful candidates who meet UKRI’s eligibility criteria will be awarded a fully-funded studentship, which covers fees, maintenance stipend (£19,237 p.a. for 2024/25) and research funding. A limited number of studentships are available for international applicants, with the difference between 'home' and 'international' fees being waived by the registering university. Please note however that ARIES funding does not cover additional costs associated with relocation to, and living in, the UK, such as visa costs or the health surcharge.
  • ARIES postgradute researcher (PGRs) benefit from bespoke graduate training and ARIES provides £2,500 to every student for access to external training, travel and conferences, on top of all Research Costs associated with the project. Excellent applicants from quantitative disciplines with limited experience in environmental sciences may be considered for an additional 3-month stipend to take advanced-level courses.
  • ARIES is committed to equality, diversity, widening participation and inclusion in all areas of its operation. We encourage enquiries and applications from all sections of the community regardless of gender, ethnicity, disability, age, sexual orientation and transgender status. Academic qualifications are considered alongside non-academic experience, and our recruitment process considers potential with the same weighting as past experience.
  • All ARIES studentships may be undertaken on a part-time or full-time basis. International applicants should check whether there are any conditions of visa or imigration permission that preclude part-time study. All advertised project proposals have been developed with consideration of a safe, inclusive, and appropriate research and fieldwork environment with respect to protected characteristics. If you have any concerns please contact us.
  • For further information, please contact the supervisor. To apply for this Studentship follow the instructions at the bottom of the page or click the 'apply now' link.
  • ARIES is required by our funders to collect Equality and Diversity Information from all of our applicants. The information you provide will be used solely for monitoring and statistical purposes; it will remain confidential, and will be stored on the UEA sharepoint server. Data will not be shared with those involved in making decisions on the award of Studentships, and will have no influence on the success of your application. It will only be shared outside of this group in an anonymised and aggregated form. You will be ask to complete the form by the University to which you apply.
  • If funded under the BBSRC-NERC DLA scheme, ARIES studentships will be subject to UKRI terms and conditions. Postgraduate Researchers are expected to live within reasonable distance of their host organisation for the duration of their studentship. See https://www.ukri.org/publications/terms-and-conditions-for-training-funding/ for more information

Apply Now

Apply now via the  University of Plymouth Application Portal