Global change biochemistry: lipid and fatty acids as biomarkers of climate dynamics and oxygen stress in a large urban lake

Global change biochemistry: lipid and fatty acids as biomarkers of climate dynamics and oxygen stress in a large urban lake 

About the project

This is an important opportunity for a first class student to contribute to our understanding of climate change effects on oxygen dynamics in freshwater ecosystems – as one of the most important controls on species and ecosystems. The project is fully funded to cover UK fees and stipend.

Freshwater ecosystems and organisms are under multiple threats, but one of the largest is from climate change which simultaneously affects flow patterns and thermal regimes. Increasing temperature has direct effects on critical environmental conditions such as oxygen concentrations, which fall as temperatures rise. Effects on organisms are likely, but still poorly understood especially from a biochemical perspective. If clarified, however, biochemical responses to oxygen stress in real ecosystems could provide important indicators of changing conditions.  

Oxygen deprivation triggers complex responses in organisms at cellular and tissue levels through which metabolic and bioenergetic demand must be matched with falling oxygen supply. Multiple, evolutionarily, conserved molecular responses are involved, including those mediated by oxygen-consuming enzymes (desaturases) that introduce double bonds into long chain fatty acids to form essential polyunsaturated fatty acids (PUFA). As oxygen concentrations fall, however, maintaining PUFA levels could become critical both to individual organisms and whole ecosystem function. This studentship will explore these themes using biological samples from a real lake ecosystem where there is a unique opportunity to i) manipulate whole-lake oxygen concentrations under different thermal conditions and ii) track inter- and intra-annual variations using biomarkers in candidate organisms (eg zebra mussels, zooplankton or algae). As such, the study provides an unusual opportunity to focus biochemical methods on global change issues.

The study site

Cardiff Bay is an artificial 200 ha lake formed in 2001 by the impoundment of the Rivers Taff and Ely at their confluence with the Severn estuary. The lake is important to amenity, recreation and culture, but is also important ecologically as part of a migratory route for Atlantic Salmon.  Dominantly for this reason, there is a specific legal requirement to maintain dissolved oxygen concentrations in the Bay at > 5 mg/L throughout the year. Cardiff Harbour Authority (CHA) deliver this need using a bay-wide aeration system but its design is being re-examined in the light of i) its age; ii) financial and carbon costs; iii) reduced BOD and improving water quality in the Taff and Ely; iv) risks of increasing summer temperatures linked to climate change and v) oxygen dynamics in the Bay linked to the aggregate effects of a large population of non-native bivalves. These needs create the opportunity for both whole-lake experimental manipulation of oxygen dynamics and biochemical assessment of the biological consequences.

The studentship and skills needed

Applicants should have biochemical/biological skills and interests suitable for appraising i) the effects of variations in oxygen concentrations using biochemical indicators of deoxygenation effects; and ii) the ecosystem consequences of changing patterns among long-chain PUFAs and membrane glycerolipids in algae (Holm et al. 2022; Science, 376, 1487-1491) and/or benthic organisms such as Zebra Mussels. They should have at least an excellent first degree in environmentally oriented biology and biochemistry with some combination of laboratory skills and, ideally, experience of working in field environments. Further research experience, for example at Masters’ level, would be an advantage.

The appointed student will be supervised by staff from Cardiff University’s Schools of Biosciences (Dr Irina Guschina: lipid biochemistry; Prof Steve Ormerod: freshwater ecology; Dr Ian Vaughan: freshwater ecology, data and modelling) and Earth/Environmental Sciences (Dr Rupert Perkins:  algology/limnology), alongside Cardiff Harbour Authority (David Hall: Cardiff Bay ecology and management).  The team also involves another PhD student focussed on physico-chemical variations.

Other details

The studentship will commence in October 2024 and will cover tuition fees (at UK level) as well as a maintenance grant. In 2022-23 the maintenance grant for full-time students was £17,668 per annum. As well as tuition fees and a maintenance grant, the students will have access to courses offered by the University’s Doctoral Academy and become members of the University Doctoral Academy.

As we expect a very high standard of applications, the successful applicant is likely to need a very good first degree (a First or Upper Second class BSc Honours or equivalent) ideally with Masters’ level experience and/or relevant research experience.

We welcome informal enquiries from interested students.

How to apply:

You can apply online – consideration is automatic on applying for a PhD, with an October 2024 start date. 

Please use our online application service at https://www.cardiff.ac.uk/study/postgraduate/research/programmes/programme/biosciences-phd-mphil-md

Please specify that you are applying for this particular project and the supervisors. 

Information on the application process can be found here: 

http://www.cardiff.ac.uk/study/postgraduate/applying 

Funding Notes

Cardiff Harbour Authority is funding this studentship and the award offered will cover UK fees and maintenance stipend.