Methane-derived carbon in upland stream foodwebs: characteristics and significance for carbon cycles

Interactions between upland terrestrial carbon stores and the river ecosystems that drain them are a key part of carbon cycling globally and understanding the patterns of storage, transformation and release of carbon from different sources is of prime importance in understanding carbon budgets within aquatic ecosystems from local to global scale.

Methane is a key greenhouse gas, with fluxes through freshwater ecosystems now recognised as being highly significant in the understanding of global carbon cycles and climate change. Previous consideration of methane in carbon fluxes and budgets of river systems has largely focused on evasion from the water surface and export in dissolved form.

The incorporation of methane as a carbon source into freshwater foodwebs via methane-oxidising bacteria (MOB) has only recently been recognised as important in our understanding of carbon cycles and foodweb processes and remains poorly understood. Previous work has shown that methane-derived carbon (MDC) is a significant source of energy in lakes and lowland rivers but methane incorporation may also be significant in upland streams, particularly those draining peat ecosystems.

This overall aim of this project is to determine the characteristics and significance of methane-derived carbon to upland river foodwebs and carbon cycling in these systems, exploring the pathways of incorporation and drivers of variation. It will be based on field survey work in upland Scotland utilising stable isotope approaches to examine broad-scale variation in the contribution of MDC and more detailed analysis of pathways and flow into and through the foodweb. This will be combined with experimental work examining spatial variation in methane incorporation and bioinformatic analysis to explore the characteristics and variation in MOB communities sampled from different ecosystem components.

The student will be based at Edinburgh Napier University, but will spend periods of time at the Environmental Research Institute, UHI, Thurso. The student will gain training and experience in a diverse range of both field and laboratory techniques including stable isotope analysis, field sampling techniques, molecular biology and use of data manipulation and statistical analysis techniques including GIS, stable isotope mixing models, gas chromatography, bioinformatics and spatial statistical modelling.
Academic qualifications

A first degree (at least a 2.1) in a relevant subject from a degree awarding body recognised by the UK government or equivalent. A relevant MSc would be an advantage.

English language requirement
IELTS score must be at least 6.5 (with not less than 6.0 in each of the four components). Other, equivalent qualifications will be accepted. Full details of the University’s policy are available online.

Essential attributes:
• Experience of undertaking field-based research, ideally in freshwater ecosystems
• Competent in using R
• Good written and oral communication skills
• Strong motivation, with evidence of independent research skills relevant to the project
• Good time management
• Full clean driving licence

Desirable attributes:
Experience of use of stable isotope analysis