Royal Netherlands Institute for Sea Research
Royal Netherlands
Institute for Sea Research

Ecosystem functioning expressed by bioturbation

Coastal areas, like tidal flats, are complex systems that are essential for human wealth by providing so called ecosystem services such as coastal protection. However, they are under pressure from various anthropogenic disturbances that reach from global (e.g. sea-level rise) to local (e.g. local dredging, bottom trawling) scales.

The EMERGO project aims at providing scientific knowledge about tidal flat eco-morphodynamics and ecological functioning to improve and optimize future management to conserve and restore tidal flats. In order to estimate ecosystem functioning we need an improved understanding of our ecosystems. Therefore, we offer research topics on bioturbation which is one of the key processes for ecosystem functioning (e.g. nutrient cycling). Despite the need of extending our basic knowledge of bioturbation patterns we aim at determining the effect of global warming on ecosystem functioning expressed by bioturbation.

During the internship you will learn about:

1) How does salinity affect ecosystem functioning?

In the context of global warming we aim to determine how desalinization influences ecosystem functioning expressed by bioturbation. Experiments (particle reworking and bioirrigation) will be carried out on the level of typical benthic community structures in the Westerschelde and/or Osterschelde (Netherlands) that will be exposed to different salinities.

2) Predicting changes in ecosystem functioning in the context of global warming: bioturbation along a salinity gradient

This study aims to determine bioturbation along the salinity gradient in the Westerschelde (Netherlands). We want to find out how salinity affects benthic community composition with regard to functional groups. Samples (cores) will be taken in the intertidal areas for vertical chl profiles (analyzing particle reworking), bromide analyses (determining bioirrigation) and the depth distribution of macrofauna within the sediment.

3) Bioturbation of Corophium volutator

C. volutator is categorized as a surficial modifier in the literature. Experiments have consistently resulted in diffusive (local) sediment mixing when using luminophores as a particle tracer. However, chlorophyll profiles determined in cores taken in the Westerschelde (station Zuidgors, where C. volutator is the most dominant species) show remarkable subsurface peaks indicating advective (non-local) transports. Experiments on the bioturbation behavior of C. volutator will be carried out comparing the luminophore and chlorophyll techniques. This study aims to prove that this species is able to induce non-local particle transport.

We are searching for (preferably) MSc students with:

• Basic knowledge of and interest in macrozoobenthos/bioturbation
• Motivated to carry out field/lab work
• Experience processing experimental data
• Willingness to publish in scientific journals

Further information

• This position can start as soon as possible
• The duration of the projects can be discussed
• Feel free to develop own ideas that can be discussed
• Contact the head of the project: Tom Ysebaert