PhD-project: “Impact of microphytobenthos on C, N, P and Si cycling in dynamic intertidal systems”

This vacancy is the result of the collaboration between Utrecht University and NIOZ. The department of Estuarine & Delta Systems (EDS) of the Royal Netherlands Institute for Sea Research (Royal NIOZ) and the department of Earth Sciences of the Utrecht University (UU) are looking for an enthusiastic PhD candidate with a degree in marine biogeochemistry or marine biology with a passion for state-of-the-art methods and mathematical modelling.

2020-12-17 08:38:20

VACANCY ID:             2020-82
CLOSING DATE:        January 20th, 2021

Intertidal euphotic sediments experience large and rapid fluctuations driven by tides and variation in light. This interdisciplinary PhD project will combine state-of-the-art measurement methods with innovative experiments and mechanistic modeling to

study sediment biogeochemistry under such fluctuating conditions, focusing on the impact of microphytobenthos (MPB). Fieldwork will elucidate the controlling influence of MPB on sediment biogeochemistry in different physical settings (inundation, sediment type) and over broad spatial scales (mm to km). Controlled lab experiments will unravel the impact of fluctuations on sediment biogeochemistry. The datasets will serve to create a new class of sediment models that explicitly couple microbiology and geochemistry.


The project will be co-supervised by Prof. Dr. Karline Soetaert (NIOZ, and lecturer at UU) and Dr. Lubos Polerecky (Department of Earth Sciences at UU). Karline Soetaert is a biologist and computer scientist who applies mathematical modelling to better understand marine processes in a variety of environments. She is an expert in numerical modelling and software development. Her recent focus includes field work and experiments to quantify anthropogenic impacts on marine biogeochemistry. Lubos Polerecky is a physicist who has developed and applied new methods (microsensors, planar O2 optodes, hyperspectral imaging) to investigate benthic primary production and aerobic processes on small spatial (microns) and temporal (minutes to hours) scales. His recent focus includes application of nano-scale secondary ion mass spectrometry (nanoSIMS) to study activity and physiology of microorganisms.

Prof. Dr. Jack Middelburg (UU) and Dr. Dick van Oevelen (NIOZ) are also part of the selection committee.


This project is uniquely situated at the interface of marine biogeochemistry, ecology and mathematical modelling. You will prepare and perform field studies, where you will measure nutrients, primary productivity and microphytobenthos biomass during inundation and exposure of tidal flats using a variety of approaches and methods including stable isotope probing, microsensors, planar optodes and hyperspectral imaging. You will devise and perform lab experiments that will unravel the impact of rapid environmental fluctuations on biogeochemistry. Finally, you will develop a new class of models of early diagenesis that couple biogeochemistry and biology and resolve the small spatial scales characteristic for sediments. The combination of the data and models will be used to reconstruct and upscale the flow of C, N, P and Si in intertidal flats, and to test how fluctuating conditions, via their effect on microphytobenthos and microbial dynamics, affect sediment biogeochemistry.


We are looking for an enthusiastic candidate who is prepared to face the challenges of this highly interdisciplinary project. You hold a MSc degree in biogeochemistry or marine ecology, and are eager to work with state-of-the-art scientific tools, perform fieldwork, design and execute dedicated experiments, and have experience with data analysis and at least basic knowledge of mechanistic modelling. Excellent oral and writing skills in English are essential. We highly encourage applicants from all members of our research community and of diverse background to join us.  


Employment of this position at Royal NIOZ is by NWO (The Netherlands Organization of Scientific Research). We offer a position for a period of 4 years (fulltime). We offer a position for a period of 1 year (fulltime). At the end of this first year, the employment will be extended for a fixed-term of a maximum of 4 years, if the first year evaluation held with the employee is positive. The salary is compliant to the CAO-OI (Collective Labour Agreement for Dutch Research Institutes), a pension scheme, a holiday allowance of 8% of the gross annual salary, a year-end bonus of 8,3%, flexible work arrangements and 42 days of holiday leave (fulltime position).

You may expect attractive secondary employment conditions. We offer generous relocation expenses for employees coming from abroad and support with finding accommodation. The position will be based at the NIOZ-Yerseke, which is at commuting distance of cities like Antwerpen, Breda, Middelburg and Vlissingen.


For additional information about this vacancy, please contact Prof. dr. Karline Soetaert (Research Leader at NIOZ), or dr. Lubos Polerecky (Assistant Professor at UU). For additional information about the procedure, please contact  Sigrid Moerbeek (senior HR advisor).

For more information about the Department of Estuarine & Delta Systems (EDS) see here. For more information about the Department of Earth Sciences, at Utrecht University see here

Find more information about the UU-NIOZ projects here.

Note: The first round of job interviews is foreseen for early February 2021 and will take place online. When feasible, a visit to the NIOZ-EDS department in Yerseke and a second interview will take place in February.



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