PhD scholarship in lake restoration and fish behaviour (DTU Aqua)

Technical University of Denmark (DTU)

Silkeborg, Denmark 🇩🇰


Are you looking for a career as a natural scientist with strong analytical skills and an applied focus, this could be a position for you. A PhD Scholarship in the interplay between lake restoration and fish behaviour is available at the National Institute of Aquatic Resources (DTU Aqua), Denmark, with starting date 20 June 2023. The scholarship is part of a project financed by the Grundfos Foundation. The project will be carried out at Section for Freshwater Fisheries Ecology, which is situated in Silkeborg, Denmark. DTU Aqua is an institute at the Technical University of Denmark.

Project background
Fish plays an important structuring role for ecosystem-dynamics in lakes. A growing dominance of zooplankton feeding fish such as roach, (Rutillus rutillus), and benthivorous fish such as bream (Abramis brama) can change lakes from a clear watered state to a turbid state, which ultimately reduces biodiversity. Attempts are often made to restore turbid lakes into clear water lakes by removing large amounts of roach (e.g., by seine fishing). The intention is to facilitate a regime shift in the lake at all trophic levels. If such removals are adequate, clear changes in fish population dynamics can be observed during the following years. For example, the removal of large proportions of roach may have a huge impact on the remaining roach in the lake due to the change in ecosystem structure. On one side, they will experience much less food competition due to the dramatic decline in roach density. On the other side the decline in roach density results in an increased predation risk from piscivorous fish and other predators. Consequently, the piscivorous fish such as pike (Esox Lucius) will also be affected by the removal of prey fish as food availability will decrease (i.e., a cascading effect). This may result in changes in seasonal and daily feeding strategies and therefore marked changes in pike activity and habitat use. In addition to these changes in competition and food availability the predator/prey interactions also depend on light regimes and water clarity. However, little is known about how such a dramatic shift in baseline living conditions for roach and pike affects their behaviour in general and across various environmental regimes.

To successfully switch a lake from turbid to clear water state through planktivorous fish biomass removal, a large proportion of the biomass needs to be removed. Fish removal efficiency likely depends on the fishing gear used and the catchability of the fish, which through variations in fish behaviour, can vary across seasons. However, little is known about how lake restoration by fish removal can be optimized by understanding fish behaviour in relation to different fishing gear.

Responsibilities and qualifications
Your job will be to explore, analyze, and publish studies on fish behaviour and specifically how fish respond to lake restoration including a focus on applied aspects, e.g., the interplay between fish behaviour and cost effective lake restoration. To do this, you will be provided with a substantial dataset of pike and roach behaviour collected by a telemetry system which continuously has tracked a number of tagged roach and pike over multiple years in a lake undergoing lake restoration by fish removal. Additionally, various biotic and abiotic measurements from the lake as well as information about the different fishing gear used during the lake restoration will also be available. You will also be involved in teaching including supervision of BSc and MSc student projects.

You must have a two-year master’s degree (120 ECTS points) or a similar degree with an academic level equivalent to a two-year master’s degree.

You should hold a M.Sc. degree in Biology, Aquatic Science & Technology or similar. It is also a prerequisite that you familiar with animal behaviour and/or freshwater/marine ecology and most important, have experience and keen interest in data science and statistical analyses (preferably using R). 

Additionally, it would be an advantage if you have:

  • Experience with telemetry (preferably high-resolution and high-throughput telemetry) and related data analysis (high priority)
  • Strong analytical skills
  • Experience with (or interest in) biological field work
  • Proficiency in written and spoken English
  • The ability to work in teams and alone.

Approval and Enrolment
The scholarship for the PhD degree is subject to academic approval, and the candidate will be enrolled in one of the general degree programmes at DTU. For information about our enrolment requirements and the general planning of the PhD study programme, please see DTU’s rules for the PhD education.

The assessment of the applicants will be made by Associate Professor Christian Skov, Senior Scientist Henrik Baktoft and researchers Martin Hage Larsen and Postdoc Nicolas Azaña Schnedler-Meyer, DTU Aqua.

We offer
DTU is a leading technical university globally recognized for the excellence of its research, education, innovation and scientific advice. We offer a rewarding and challenging job in an international environment. We strive for academic excellence in an environment characterized by collegial respect and academic freedom tempered by responsibility.

Salary and appointment terms
The appointment will be based on the collective agreement with the Danish Confederation of Professional Associations. The allowance will be agreed upon with the relevant union. The period of employment is 3 years.

Starting date is 20 June 2023 (or according to mutual agreement). The position is a full-time position. The PhD student will be based at DTU Aqua in Silkeborg, Denmark, and will be integrated in the Freshwater Fishery and Ecology section, DTU Aqua. A certain amount of field work can be expected.

You can read more about career paths at DTU here.

Further information
Further information may be obtained from Associate Professor Christian Skov, tel.: +45 35883116, email: [email protected]

You can read more about the institute at

If you are applying from abroad, you may find useful information on working in Denmark and at DTU at DTU – Moving to Denmark. Furthermore, you have the option of joining our monthly free seminar “PhD relocation to Denmark and startup “Zoom” seminar” for all questions regarding the practical matters of moving to Denmark and working as a PhD at DTU.

Application procedure
Your complete online application must be submitted no later than 10 April 2023 (Danish time).

Applications must be submitted as one PDF file containing all materials to be given consideration. To apply, please open the link “Apply now”, fill out the online application form, and attach all your materials in English in one PDF file. The file must include:

  • A letter motivating the application (cover letter)
  • Curriculum vitae
  • Grade transcripts and BSc/MSc diploma (in English) including official description of grading scale
  • A draft project description: 2 or 3 pages with specific proposals on research ideas that the candidate would like to explore within the topic, including relevance and motivation and the theoretical framework. If possible, also include suggestions of potential data analyses to address the research questions and the results expected.

You may apply prior to ob­tai­ning your master’s degree but cannot begin before having received it.

Applications received after the deadline will not be considered.

All interested candidates irrespective of age, gender, race, disability, religion or ethnic background are encouraged to apply.

The research of the Section for Freshwater Fisheries and Ecology, DTU Aqua is focused on the relation between environmental parameters and various fish species in streams, lakes and coastal areas. This includes investigations of natural and man-made impacts on the populations including the effects of habitat deterioration, physical obstructions, eutrophication of lakes and development of new lakes and wetlands. The Lake ecology group is part of the section and is a small group, united by our dedication to exploring the implications of fish behavior for lake ecology and restoration. As a group, we combine diverse skillsets like data handling, ecosystem modelling and traditional ecology with world-leading expertise in underwater telemetry.  As a member of our group, you will be expected to show dedication and independent initiative, but will be working in close collaboration with the rest of the group in a friendly and relaxed atmosphere characterized by mutual discussion, interest, and feedback.

Technology for people
DTU develops technology for people. With our international elite research and study programmes, we are helping to create a better world and to solve the global challenges formulated in the UN’s 17 Sustainable Development Goals. Hans Christian Ørsted founded DTU in 1829 with a clear mission to develop and create value using science and engineering to benefit society. That mission lives on today. DTU has 13,400 students and 5,800 employees. We work in an international atmosphere and have an inclusive, evolving, and informal working environment. DTU has campuses in all parts of Denmark and in Greenland, and we collaborate with the best universities around the world.





IHE Delft Institute for Water Education - MSc in Water and Sustainable Development