MaMa Course student projects

Project 1: Tidal dynamics of the Marsdiep

The Wadden Sea is a complex tidal ecosystem, changing continuously in terms of currents, waves, sea level, temperature, salinity, sediment concentration and hence light conditions and availability of nutrients. This dynamic environment drives the biodiversity and productivity of the lower parts of the food chain (phytoplankton and zooplankton). In this project you will use temperature and salinity observations, as well as recorded velocities, over the entire depth of the field site to characterize the water flowing through the Marsdiep during one complete tidal cycle. Analysis will reveal whether there are differences in water masses and whether there is net in- or outflow through the inlet. Biotic and abiotic consequences of the observed hydrodynamic conditions can then be derived. For this project, programming experience is required (preferably Matlab or Python).

Project 2: Tidal dynamics and their effect on sediment transport

Every day, tidal currents move tons of suspended sediment from the North Sea into the Wadden Sea and back again, through the tidal inlets that breach the Wadden Sea island chain. In the Wadden Sea, sheltered by the barrier islands against the force of incoming waves from the North Sea, sediment particles suspended in the seawater settle out on the seabed. With time, sediments accumulate into vast tidal flats emerging during low tide, which are the typical landscape element of the Wadden Sea and an important habitat for marine life. Whether this landscape will remain during future sea level rise and local seabed subsidence depends on the balance of sediment import and export through the tidal inlets. In this project, you will quantify suspended sediment transport in the Texelstroom in relation to the dynamics of the tide.

Project 3: Investigating the contributions of primary producers to the Wadden Sea food web using stable isotopes

At the base of the Wadden Sea food web there are two main food sources according to stable isotope ecology, Micro Phyto Benthos (MPB) and phytoplankton. Depending on where you are one will be more important than the other, but in total it is thought that MPB supports a little over half the Wadden Sea food web. We will sample an intertidal mudflat for MPB, shrimps and possibly crabs and deeper water sediment, shrimp, crab and Particulate Organic Matter (POM, including phytoplankton). Water and shrimps (and possibly crabs) will also be sampled during a cruise along a transect from Texel to Den Oever. On the way from Texel, we will sample water (POM) and on the way back to Texel we will sample shrimp and crabs. These samples will allow us to relate the dependence of shrimp on either MPB or Phytoplankton at different depths and different salinities and potentially fresh water (and phytoplankton) input from Lake IJssel.

Project 4: How shelf seas help reduce climate change

Continental shelf seas play an important part in the carbon cycle. Growth of phytoplankton in highly productive shelf sea waters drives CO₂ uptake from the atmosphere, slowing the effect of our greenhouse gas emissions on Earth’s climate. In the North Sea, CO₂ uptake is boosted by alkalinity supplied from chemical reactions in the sediments, particularly in shallow areas like the Wadden Sea, and river waters. Elevated alkalinity also mitigates ocean acidification. In this project, we will measure dissolved CO₂, alkalinity and pH in seawater samples that we will collect on a transect from Texel (where the Wadden and North Seas connect) to the IJsselmeer (freshwater endmember for the Wadden Sea) plus water samples from the IJsselmeer itself. From the data, we will determine the balance of alkalinity supply: how much comes from the IJsselmeer and how much from the sediments? This balance is important to determine for future climate projections, as each supply may respond differently to human pressures and management decisions. We will also calculate how much extra CO₂ is stored as a result and find the effect on seawater pH and carbonate mineral solubility.

Project 5: Spatio-Temporal dynamics of sediment temperature in the Dutch Wadden Sea​

Tidal flats are vital coastal areas regularly shaped by the tides. These ecosystems are important for coastal protection, biodiversity, and local economies, but they are sensitive to extreme weather events, such as heatwaves, which can strongly affect their temperature and ecological function. Recently, the Wadden Sea has experienced mass mortality of bottom-dwelling organisms due to extreme warming. However, we still lack precise data on how sediment temperature changes under different weather conditions, limiting our understanding of how climate change will impact this ecosystem. In this project, you will deploy high-frequency temperature loggers along an intertidal gradient to track temperature fluctuations across multiple tidal cycles. In the lab, you will analyze this fieldwork data to map the spatio-temporal dynamics of intertidal seafloor's thermal variability and develop a simple mechanistic model of the sediment heat budget over the Wadden Sea. Depending on time, you will also investigate how these temperature shifts impact the composition and abundance of local marine fauna.

Project 6: The diversity of decapods and their infecting parasites in the Wadden Sea 

Decapods (shrimps, crabs and the likes) ensure important ecological functions in the Wadden Sea by regulating nutrient cycles and serving as key food sources for birds, fish and humans. Beyond these functions, decapods also serve as hosts for various parasites, which are themselves important components of the ecosystem. Despite their importance, we know surprisingly little about the diversity of decapods and decapod-infecting parasites, and how it changes along the heterogeneous underwater landscape of the Wadden Sea. Better understanding how ecological communities of decapods and their infecting parasites vary along the sea floor is key to predicting how future changes in the marine environment will affect them, and the services they provide. In this project, you will start by using various methods (dredge, hand net, traps) to collect decapods across contrasting habitats in the Wadden Sea. Then, you will characterize both decapod and infecting parasite communities by identifying, measuring and sexing these organisms in the field and laboratory. Finally, you will use quantitative community ecology approaches to attempt to link the composition of these communities and environmental variables.