His research focuses on diversity and distributions of marine macroalgae, where he addresses questions ranging from purely descriptive taxonomic studies to more ecologically oriented studies forecasting the distribution of species in relation to environmental changes. With respect to the latter he was involved in the development of Bio-ORACLE, a set of GIS rasters providing marine environmental information for global-scale applications that can be used for Ecological Niche Modeling. Next to descriptive taxonomic work, he’s intrigued by the effect of recent technological developments (e.g DNA-sequencing technology) on our understanding of algal species boundaries, global diversity estimates, biodiversity patterns and current taxonomic practices. A more recent line of interest concerns our focus on the interplay of algal community structure, evolutionary relatedness of the composing species and functional trait diversity. Thereto, he initiated the establishment of a trait database for marine macroalgae (Emodnet framework). The focus here is on European seaweed diversity which is under severe pressure from both local as well as global stressors. A first version of this trait database lists life history, ecological and morphological characteristics of all European seaweed genera (~ 800 genera). Gradually, however, this framework is refined to species-level.