Temporal and spatial variation in the condition of small pelagic fish in the Dutch Wadden Sea

Wageningen Marine Research (WMR) is looking for a student to study the condition of herring, sprat, smelt and sandeel in the Dutch Wadden Sea by means of lab work and data analysis.

Small pelagic fish are the major trophic link between zooplankton and predators such as piscivorous birds and seals. However, despite their importance small pelagic fish remain understudied in the Wadden Sea. In this research project more insight in the condition of herring, sprat, smelt and sandeel will be gained. These are the most abundant small pelagic fish species in the Wadden Sea, and important prey for birds such as terns.

The student project will be part of a larger study, Swimway-Waddentools, that aims to gain insight in the role of the Wadden Sea for small pelagic fish. In the Swimway-Waddentools project, a monthly stow net survey was conducted in 2021-2022 and an acoustic survey was conducted in May & October 2022. Many individual fish were measured for length and weight, and >300 fish were collected for lab analysis. Part of these fish are already analysed for their caloric value using a bomb-calorimeter and an ‘ash free dry weight ~ energy’ relation was established.

This research project is composed of two parts:

  1. To perform ash free dry weight analysis of the remaining fish, to be able to calculate their caloric values. This needs to be done in our lab in IJmuiden.
  2. To perform data analysis on the length-weight relations of the different species, over multiple months and seasons. In addition, it will be possible to study spatial variation, as 5 different inlets are sampled over time. It would be best if the student could work in IJmuiden during this stage, but it is also possible to partially work from home.

We are looking for a student that is able to work independently, and with experience in data analysis using R. If you are interested please reach out to Margot Maathuis, and we can discuss about the details (starting date / duration / level etc.).

Practical information