MSc Thesis Opportunity: Survival in an Extreme Environment - Microbial activity and organic matter preservation within high arctic lake bottom sediments

High arctic limnic systems are extreme environments with poorly understood geomicrobiological controls for the diagenetic alteration of sedimentary organic matter (SOM). Even for lakes experiencing non-permanent ice cover, SOM input by photosynthetic activity is largely limited to a two-month annual growing season with accumulation restricted to a shallow layer that rests above the permafrost. Under these conditions nutrient loading, productivity, and OM cycling are heavily limited to discrete temporal and spatial intervals. One such limnic system is Colour Lake, conveniently located next to the McGill Arctic Research Station (MARS) on Axel Heiberg Island, Nunavut (Canadian High Arctic). The small, naturally acidic (pH 3.7) lake is nestled in rocks of the late Devonian Franklinian geosyncline, which is overlain by a thick sequence of predominantly clastic sedimentary rocks deposited in the Sverdrup Basin. It is expected that the decay rate of volatile organic matter is uniquely microbially spatial-chemically controlled and determined by redox changes within the shallow sediment lake system. To verify this hypothesis, the MSc student will examine the SOM contributions being added to the bottom sediments. Two orthogonal sediment core transects will be collected along the length and breadth of the lake. Downcore lipidomic and 16S rRNA surveys will detail the abundance and diversity of microbiological activity. Targeted and untargeted lipidomic surveys will map occurrences of lipids in their biological form (aka with a polar headgroup that is usually phosphate-, amino-, or sulphate-based and of glycosidic species) attached to the glycerol of a fatty acid or ether- and ester- bound core lipid (CL).

Research tasks:

• Participate in sample collection on Colour Lake, Axel Heiberg Island, Nunavut (Canadian High Arctic)
• Formalize wet chemistry procedures for the extraction and separation of bacterial and archaeal IPLs and PLs with authentic standards and matrix-matched reference materials.
• Identify and quantify the various IPLs and PLs within collected the water filtrate samples.
• Relate these data to existing, geochemical, genomic, and/or porewater geochemical data.

Candidates with the following qualifications are encouraged to apply:

• Strong academic background.
• Passionate research interest and a capability to learn organic geochemistry.
• Very good command of spoken and written English, i.e. TOEFL IBT (overall score of 88 or better, minimum score of 20 in each of the four components: listening, speaking, writing, reading) or TOEFL PBT (paper-based test, minimum score of 570, minimum essay score of 5). 

This degree offers:

• A cutting-edge research project using state-of-the-art, modern analytical equipment.
• A training program tailored to the needs of the student.
• The ability to present research findings at national conferences; and
• A friendly and multi-disciplinary environment;

Expression of interest including CV, academic transcript and the names of three references should be sent to Prof. G. Todd Ventura (todd.ventura@smu.ca).

Closing date: 20^th January 2025

Starting date: 1^st August 2025 (But field work will be in July or August 2025).

Application review will begin from the start of this search and continue until the position is filled or the closing date is reached. Saint Mary’s University in Halifax, Nova Scotia offers an MSc in Applied Science. The successful candidate will join our growing SMU Organic Geochemistry Laboratory (SMU OGL) research group, which currently includes 1 Postdoc and 3 PhD student, and an intern. This position includes costs of tuition and a living stipend. The MSc student will also have opportunities to be a teaching assistant and to apply for additional external funding.

For informal enquiries and further information about this research project and the academic setting of SMU contact Dr. Todd Ventura, email: todd.ventura@smu.ca.

For more information concerning the OGL research group please see: https://www.smu-ogl.com/

For further details about studying at Saint Mary’s University see: http://www.smu.ca and

http://www.smu.ca/academics/departments/geology.html.