The Biological Carbon Pump and particle fluxes in the North Sea

The Biological Carbon Pump (BCP) is a central component of the Earth’s climate system. It describes a series of biological and physical processes that produce and transport organic matter from the surface ocean to depth via the settling of organic aggregates. Organic tissue and biominerals are synthesized by phytoplankton from CO₂ and nutrients in surface water. Upon death, these cells slowly sink towards the seafloor in various forms as so-called ‘marine snow’. The resulting net transfer of organic matter from the surface to the deep ocean interior not only sustains deep-sea ecosystems but also locks away carbon from interaction with the atmosphere for millennia. However, the magnitude of these fluxes depend on the transformation of sinking particles during their journey through the water column.

In order to study the exchange of carbon and nutrients between the North Sea and the Atlantic ocean, we look at lateral and vertical fluxes of particulate matter within the Norwegian Trench, the main outflow route of water from the North Sea towards the Atlantic Ocean. To study vertical fluxes two moorings and one lander equipped with sediment traps and environmental sensors were deployed in the Norwegian Trench for the duration of one year. These sediment traps will provide a record of seasonal surface export and will allow us to quantify mass and (in)organic matter fluxes, while measurements of stoichiometry and isotopic ratios allow us to assess the quality and bio-availability of the suspended particulate matter. Finally, we will reconstruct the influence of hydrodynamics on both lateral and vertical particle fluxes by linking the sediment trap data with the sensor data (current direction and speed, fluorescence, turbidity).

In this project, you will quantify the seasonal variation in marine particle fluxes and their sedimentological and chemical composition in order to elucidate the importance of BCP processes in the biogeochemical C/N cycles in the Norwegian Trench. The internship will involve processing of sediment trap samples using analytical methods (e.g. mass spectrometry, XRF, grainsize) in the laboratory, subsequent data analysis and interpretation.

Requirements

We are looking for a highly motivated MSc student with a background and keen interest in earth sciences and/or (biogeo)chemistry. The project has a large lab component, during which you will perform chemical experiments that require high accuracy and precision. Projects have a planned duration of 6 months and will take place at NIOZ, Texel. Goals will be set according to duration and students’ interests. Results will be presented in a written report, as well as an oral presentation at the end of the internship.