PhD position: Tide-dependent foraging behaviour of marine mammal and seabirds in relation to anthropogenic and natural discontinuities

Are you interested in studying the foraging behaviour of marine mammals and seabirds in the North Sea and do you have the necessary analytic skills?

We are looking for a motivated PhD candidate to join our research team on marine mammal and seabird ecology with a focus on understanding how offshore windfarms influence the temporal dynamics in foraging behaviour and prey capture by marine top predators in the North Sea.

Key responsibilities:

• Analyse tracking data of seals and seabirds to investigate their foraging behaviour in relation to dynamic environmental variables, such as tidal currents, and investigate how these foraging dynamics are influenced by natural discontinuities and man-made structures in the North Sea;
• Conduct research from vessels, which includes dedicated surveys of foraging behaviour in relation to discontinuities, including the collecting of drone-based measurements on (multi-species) feeding events and how they relate to locally measured spatially and temporally dynamic environmental conditions;
• Integrate empirical data analysis into conceptual models to investigate how altered conditions due to offshore wind farms may lead to broader ecological impact across the North Sea;
• Publish research findings in peer-reviewed journals and present them at national and international conferences;
• Mentor BSc/MSc students.

About your NO-REGRETS subproject
The rapid increase of anthropogenic structures in the North Sea, most notably due to the expansion of offshore windparks, may have multifaceted effects on marine ecosystems. In addition to the direct consequences of introducing foreign hard substrates into the marine environment, there are many indirect effects, such as changes in flow velocities and turbulence. These can lead to changes in vertical water structure, such as loss of stratification, but also changes in sediment composition in the surrounding habitats. These habitat changes will impact marine organisms, including fish species, which may ultimately propagate to top predators like marine mammals and seabirds present in the North Sea.

The objective of this PhD is to take a predator’s perspective and investigate how foraging activities of marine mammals and seabirds changes as a function of changes in currents. Since current regimes continuously vary with the tidal cycle, changes in the availability and catchability of prey should manifest itself in tidally dependent variation in foraging activities. More specifically, the PhD project will focus on the following research questions: How do foraging activities of tracked seals (grey and harbour seals) and seabirds (sandwich terns) vary within the tidal cycle and how does this depend on the type of habitat?

You are/ You have :

• A Master’s degree (or will graduate before appointment date) in Biology, Marine Biology, Ecology or Environmental Science;
• Strong statistical analysis skills;
• Proficient in the application of spatial analysis in R;
• Familiar with the North Sea marine ecosystem;
• Interested in sea going fieldwork;
• An independent and pro-active personality that is willing to foster a close collaboration with a diverse group of researchers, who are employed at various organisations and locations;
• A proactive, inquisitive, enthusiastic, creative and self-reliant mind-set;
• Strongly motivated to obtain a PhD degree;

Excellent English language proficiency (a minimum of CEFR C2 level). For more information about this proficiency level, please visit our special language page.

You will work here
The position is available within Wageningen University & Research at the Wildlife Ecology and Conservation Group (WEC) and Wageningen Marine Research (WMR – Den Helder). Regular in-person meetings will take place in Den Helder, Wageningen and the NIOZ on Texel .

The people of WEC study how humans influence wildlife. We examine both direct mechanisms like hunting and fire, and mechanisms that are more indirect and that are part of larger-scale processes, such as climate change. WMR is an applied research institute with 3 locations (Den Helder, IJmuiden and Yerseke) in the Netherlands. In Den Helder a broad group of scientists works on benthic ecology, seals, seabirds, bats and other species. As a member of the marine mammal and seabird team, you will closely work with Sophie Brasseur, Martin Baptist, Martin Poot, and other marine mammal and seabird researchers. The NO-REGRETS project has a strong offshore data collection component, and you are expected to take part in 10-20 days scientific research cruises at sea, during 2 years (2026-2027).

About the NO-REGRETS project
This multidisciplinary research is part of the broader NO-REGRETS project, funded by the Netherlands Organization for Scientific Research (NWO), and involves a collaboration between Wageningen University & Research with the Royal Netherlands Institute for Sea Research (NIOZ), TU Delft, TU Eindhoven, Naturalis, University of Amsterdam and multiple others. Further project partners involve a broad range of stakeholders in the North Sea area, including NGO’s, Dutch government and the offshore wind industry.
The interdisciplinary NO-REGRETS project will generate and integrate knowledge on how offshore wind farms (OWFs), fisheries and other activities such as sand and gravel extraction may interact in the North Sea to cause: i) changes in physical dynamics of water currents, nutrient availability, plankton, benthic organisms and upper trophic levels (fish and mammals) to understand marine food web impacts, ii) changes in ecology at OWFs and other factors (e.g. changes in fisheries, and ongoing and future climate impacts), and iii) cumulative impacts on the natural capital of the North Sea including ecosystem services. 12 PhD’s and other scientific staff will work on this project.

Wageningen University & Research offers excellent terms of employment. A few highlights from our Collective Labour Agreement include:

• Partially paid parental leave;
• working hours that can be discussed and arranged so that they allow for the best possible work-life balance;
• there is a strong focus on vitality and you can make use of the sports facilities available on campus for a small fee;
• a fixed year-end bonus of 8.3%;
• excellent pension scheme.

In addition to these first-rate employee benefits, you will receive a fully funded PhD position and you will be offered a course program tailored to your needs and the research team.

The gross salary for the first year is € 2.901,- per month rising to € 3.707,- in the fourth year in according to the Collective Labour Agreements for Dutch Universities (CAO-NU) (scale P). This is based on a full-time working week of 38 hours. We offer a temporary contract for 18 months which will be extended for the duration of the project if you perform well.

Wageningen University & Research offers plenty of opportunities for growth and development, with a strong internal recruitment policy and excellent training programmes.

Coming from abroad
Wageningen University & Research is the university and research centre for life sciences. The themes we deal with are relevant to everyone around the world and Wageningen, therefore, has a large international community and a lot to offer to international employees.

Because we expect you to work and live in the Netherlands our team of advisors on Dutch immigration procedures will help you with the visa application procedures for yourself and, if applicable, for your family.
Feeling welcome also has everything to do with being well informed. We can assist you with any additional advice and information about for example helping your partner to find a job, housing, or schooling. Finally, certain categories of international staff may be eligible for a tax exemption on a part of their salary during the first five years in the Netherlands.

Wageningen University & Research
The mission of Wageningen University & Research is ‘To explore the potential of nature to improve the quality of life’.

We pursue this mission through a synergistic approach between Wageningen University and Wageningen Research Foundation (applied research). Our research focuses on questions within the domains of food, living environment, and society. With approximately 30 locations, 7,700 staff members, 2,500 PhD candidates, and over 13,000 students, Wageningen University & Research is among the world’s leading knowledge institutions in its domain. The integral approach to challenges and the collaboration across various disciplines form the core of the unique Wageningen approach.

Read the 5 reasons why your future colleagues enjoy working at WUR and watch this video to get an idea of our green campus!

We will recruit for the vacancy ourselves and do not appreciate unasked for services from recruitment agencies. However, sharing in your network is appreciated.

Do you want more information?
For more information about this position, please contact Geert Aarts, geert.aarts@wur.nl or Frank van Langevelde, Frank.vanlangevelde@wur.nl.

For more information about the procedure, please contact Edgar Tijhuis, corporate recruiter, edgar.tijhuis@wur.nl.

Ready to apply?
You can apply directly using the apply button on the vacancy page on our website which will allow us to process your personal information with your approval.

This vacancy will be listed up to and including 21 July 2025. We aim to schedule the first job interviews in the beginning of September 2025.

Welcome, safe, and valued
Wageningen University & Research (WUR) highly values diversity and inclusion because we believe that different insights lead to innovative solutions. We create a work environment where everyone feels welcome, safe, and appreciated, regardless of background, identity, or experience. Together, we are building a culture where everyone's unique contribution adds to the success of our organization.