PhD Position in Aquatic Biogeochemistry and Microbial Ecology – Benthic-Pelagic Coupling in Oxygen-Depleted Waters University of Southern Denmark in Denmark

The Department of Biology at the University of Southern Denmark is offering a fully funded PhD position in aquatic biogeochemistry and microbial ecology, focusing on benthic-pelagic coupling in oxygen-depleted coastal waters. This 3-year position is part of the ERC Synergy project RECLESS, which investigates recycling versus loss in the marine nitrogen cycle, with a particular emphasis on the controls, feedbacks, and impacts of expanding low oxygen regions in the ocean.

RECLESS brings together researchers from the University of Southern Denmark, University of Gothenburg, University of Vienna, and Carnegie Science, integrating oceanographic, biogeochemical, ecophysiological, and model-based approaches. The successful candidate will explore and quantify how benthic processes affect the exchange of matter between sediment and water column, ultimately influencing pelagic nitrogen cycling. Research will include studies of microbial processes and fluxes within sediment and the benthic boundary layer, a poorly understood aspect of coastal systems. As oxygen depletion spreads globally, this project addresses knowledge gaps of both local and global significance.

Key tasks include biogeochemical sediment analyses, measurement of benthic exchange rates, experimental studies of microbial processes in sediment and the benthic boundary layer, and implementation of findings in reaction-transport models. The project is closely integrated with pelagic process investigations within RECLESS, and participation in international research cruises is expected.

The selected candidate will join Professor Bo Thamdrup’s research group within the Nordcee section, a diverse and international part of the department. Nordcee explores six major research areas: Microbes and Element Cycles, Deep-sea Research, Co-evolution of Life and Earth, Oxygen, Greenhouse Gases and Climate, Sustainability and Biotechnology. The group focuses on how microorganisms interact with their environment, influence biogeochemical cycling, and contribute to climate and sustainability solutions.

Applicants should have a strong background in experimental (bio-)geochemistry, microbial ecology, or related fields, and be experienced in field work. Experience with biogeochemical sediment analyses, benthic exchange measurements, experimental microbial studies, or reaction-transport modeling is desirable. A relevant master’s degree is required.

The position is fully funded for three years. For full details on funding, eligibility, and application procedures, please consult the official call on the University of Southern Denmark website. The application deadline is 30 January 2026 at 23:59 local Danish time.

For more information and to apply, visit Nature Careers or the University of Southern Denmark website.