The project aims to study matter and energyfluxes in an ecosystem, in particular the fluxes between benthos, plankton and nekton, including parasites. Westerschelde and North Sea are the main study areas. Taxonomy and ultrastructure studies are included (mainly in Copepoda, Nematoda, Plathelminthes). The LUC-group studies ecology andtaxonomy of the Turbellaria, and the morphology and functions of the bursal organs in this taxon.