Mapping Shrimp and Crab distributions on Wadden Sea intertidal flats

To understand the distribution of animals, it is essential to understand the distribution of their food. For decades, the NIOZ has been sampling the Wadden Sea to map the distribution of macrobenthic species, for example to explain the distribution of shorebirds. Soil samples are taken on foot or by boat using a corer (Synoptic Intertidal BEnthic Survey (SIBES), see photo 1). This method is very suitable for sampling sessile species such as shellfish (Bijleveld et al. 2025), but it has limitations for determining the densities of shrimp and crabs. These animals are mobile and may escape before they can be sampled with a corer.

For this reason, since 2016 we have been using a different method to map shrimp and crab densities and relate them, among other things, to the distribution of sanderlings. Sanderlings are tracked with transmitters throughout the Wadden Sea (Bijleveld et al. 2022), while the sampling of shrimp and crabs took place only around Griend.

We are very interested in a comparison of the two sampling methods with the ultimate goal of estimating shrimp and crab distribution for the entire intertidal Wadden Sea. The research involves processing the 2025 samples in our benthos lab and subsequently comparing the sorted samples from 2016–2025. In addition to the samples collected in previous years, a grid was sampled in 2025 using both methods simultaneously.

Requirements

The student will learn how to analyze, plot and interpret community data, also gaining experience in data-set wrangling in R. The student can join the fieldwork for the 2026 sampling in early August around Griend (not a requirement). There may be other opportunities to gain fieldwork experience, such as participating in shorebird-catching sessions. The project duration is 6 months. The student can start the project at any time. 

Contact

For more information, please contact Dr. Emma Penning (emma.penning@nioz.nl).