Exploring river-induced stagnation as a novel driver of coastal hypoxia in the tropics


In this exciting and novel PhD project, you’ll assess the role of large rivers to promote marine hypoxia in a Caribbean Bay.

Ocean deoxygenation is an increasing problem in coastal waters around the world. Hypoxia (dissolved oxygen < 2 mg/L) can result in the catastrophic mortality of marine life as evidenced by marine “dead zones”.  Tropical marine hypoxia is under-reported and under-studied compared to hypoxia in temperate and sub-tropical ecosystems.

In the case of Almirante Bay, in Panama, there is annual hypoxia. There are a few proposed reasons for the hypoxia, including shallow bathymetry of the Bay, weak tides, wind patterns, anthropogenic nutrient inputs, and freshwater inputs. Marine hypoxia impacts coral reef and ecosystem health, tourism, and livelihoods in the Bay.

Preliminary model outputs for Almirante Bay suggest that the drivers of hypoxia in tropical bays may differ from the drivers of temperate and sub-tropical systems as excess nutrient inputs are often the main factor. Through this project you’ll provide novel insights into how freshwater inputs, specifically large rivers, prevent coastal water column turnover and promote stagnation, eutrophication, and hypoxia in tropical coastal areas.

What you’ll do:

You’ll carry out field research in the Caribbean in Panama. You’ll spend two months in Panama at the Smithsonian Tropical Research Institute (STRI) at the Bocas del Toro Research Station. You’ll collect water samples for water and nitrate stable isotope analyses and monitor physical/chemical parameters in Almirante Bay using a YSI Sonde. Back in Liverpool, you’ll analyse your samples for nitrate isotopes in the LIFER Lab, create a mixing model utilising established programming scripts with your results, determine the role of freshwater pulses in preventing turnover in Almirante Bay, and summarise the conditions when rivers promote hypoxia. Finally, you’ll make recommendations to the hydroelectric company on when they should reduce flows to promote reoxygenation in the Bay.  

Supervision team:

Through international collaboration, including external co-supervisors, you’ll have a unique experience. You’ll be a part of a cohesive, diverse, interdisciplinary, and successful research team with supervisors: Clark and Mahaffey (University of Liverpool), Collin (STRI), Torres (Rice University), and Kastner (Washington Western University).

Start Date: 1st October 2023

Further Details:

This PhD project is funded by The Faculty of Science & Engineering at The University of Liverpool and will start on 1st October 2023

Successful candidates who meet the University of Liverpool eligibility criteria will be awarded a Faculty of Science & Engineering studentship for 3.5 years, covering UK tuition fees and an annual tax-free stipend (e.g. £17,688 p.a. for 2022-23).

Faculty of Science & Engineering students benefit from bespoke graduate training and £5,000 for training, travel and conferences.

The Faculty of Science & Engineering is committed to equality, diversity, widening participation and inclusion. Academic qualifications are considered alongside non-academic experience. Our recruitment process considers potential with the same weighting as past experience. Students must complete a personal statement profoma and ensure this is included in their online application.

How to Apply:

All applicants must complete the personal statement proforma. This is instead of a normal personal/supporting statement/cover letter. The proforma is designed to standardise this part of the application to minimise the difference between those who are given support and those who are not. The proforma can be found here: https://tinyurl.com/ym2ycne4. More information on the application process can be found here: https://tinyurl.com/mwn5952t. When applying online, students should ensure they include the department name in the ‘Programme Applied For’ section of the online form, as well as the Faculty of Science & Engineering as the ‘studentship type’ in the finance section.

Application Web Address: https://www.liverpool.ac.uk/study/postgraduate-research/how-to-apply/ 


Open to UK applicants

Funding information

Funded studentship

UK students are only eligible for a fully-funded  Faculty of Science & Engineering studentship; overseas students are eligible to apply if they can financially cover the difference in UK and Overseas tuition fees, cover the costs of their student visa, NHS health surcharge, travel insurance and transport to the UK, as these are excluded from the funding.