Molecular resolution of historic and contemporary food web interactions in lake ecosystems
Dr S Thackeray
Prof S Ormerod
No more applications being accepted
Competition Funded PhD Project (European/UK Students Only)
Cutting-edge DNA techniques provide increasing opportunities to address traditionally-intractable questions about the structure and functioning of lake ecosystems. The planktonic communities of rivers and lakes are highly diverse and ecologically important. However until recently it has been difficult to examine the trophic interactions of these communities and how they respond to environmental disturbance. Improving our understanding of these dynamics will contribute to advancing both ecological theory and knowledge of the processes that are important for ecosystem services such as freshwater provision.
Planktonic predator-prey relationships are challenging to observe directly in nature (e.g. Nielsen & Winder 2015). However, knowledge of these interactions is essential to understanding lake ecosystem structure, energy flow and dynamics. In the absence of such insight researchers have inferred trophic linkages based upon experiments, or have grossly simplified them. However molecular methods, in principle, allow the resolution of these elusive links (King et al 2008). In this project, DNA meta-barcoding of natural prey and predators among zooplankton, macroinvertebrates and fish, will be used in conjunction with standard microscopy to determine food-web linkages, feeding selectivity and trophic specialisation. As well as in modern lakes, molecular methods will be used to characterise long-term changes in community structure at different trophic levels in response to known environmental pressures, via analysis of lake sediment cores. Key research questions are:
• How does the food-web structure of lake ecosystems vary over time, and among lakes?
• How well “connected” are different species in these food-webs?
• How has food-web structure changed over the long-term, in response to environmental pressures?
The successful candidate will collect water and sediment samples, and environmental data, from CEH lake monitoring sites in Cumbria (http://www.ceh.ac.uk/our-science/monitoring-site/lake-observatories) and Wales. The project will have extensive field and laboratory work components.
The student will be based at the Lancaster site of the Centre for Ecology & Hydrology (CEH) for the majority of the project, but will spend periods of up to 6 weeks per year at the Wallingford site of CEH, and Cardiff University. The PhD will be awarded by Cardiff University (University supervisor: Prof Steve Ormerod).
In all cases, applicants must have either obtained, or be about to obtain, a 2.1 degree or higher or have a 2.2 degree, with a Masters qualification. Substantial relevant post-graduate experience may also be sufficient in certain cases.
- A degree qualification in a subject such as Ecology, Biology or Environmental Science.
- Enthusiasm and ability to undertake laboratory analysis and field sampling on lakes, in all conditions.
- A proactive attitude, and self-motivation.
- Full UK driving license.
- Good communication skills.
- Numeracy, and a grounding in computer programming and statistical analysis of ecological data.
To apply please send your CV and a covering letter stating your suitability for the project and motivation to undertake a PhD by email to lead supervisor Dr S. Thackeray ([Email Address Removed])
This project is one in competition for funding from the NERC GW4+ DTP (http://nercgw4plus.ac.uk/).
The majority of these studentships (fees and stipend) are only available to UK or EU nationals that have resided in the UK for three years prior to commencing the studentship. Citizens of EU member states are eligible for a fees-only award, and must show at interview that they can support themselves for the duration of the studentship at RCUK level.
Nine studentships are available to EU students who do not ordinarily reside in the UK (this may be subject to change pending post EU referendum discussions).
Nielsen & Winder 2015, Marine Ecology Progress Series, 531, 143-154
King et al 2008, Molecular Ecology, 17, 947-963