Current projects

The biological fixation of dinitrogen (N2) by specialized prokaryotic plankton so-called 'diazotrophs' constitutes the major external source of nitrogen to the oceans and sustains primary productivity and carbon export in ~70% of the global ocean surface. N2 fixation also maintains the global nitrogen reservoir, counteracted by fixed nitrogen loss processes including denitrification and anammox.

The fixed nitrogen stock of the ocean drives global productivity and needs to be quantified accurately. To date, N2 fixation studies have taken place in a largely group specific, geographical and seasonal biased way: attributed solely to photosynthetic diazotrophic cyanobacteria that inhabit the warm and oligotrophic surface waters of the (sub)tropical oceans. 

• • We study N2 fixation data in previously unexplored habitats such as coastal upwelling ecosystems and the dark ocean the unveal the real extent of nitrogen inputs to the ocean.

  • We investigate the environmental drivers of N2 fixation and diazotroph diversity with interdisciplinary approaches, combining stable isotope tracing, organic geochemistry, nanotechnology and molecular biology techniques.