Due to changes in the North Sea, such as the warming of the waters, sea level rise and the construction of large-scale wind farms, changes may occur within the benthos and plankton communities. This is just part of the reason we are monitoring waters in the Dutch Delta and Wadden Sea. We map species diversity, make trend analyses and identify new, and sometimes non-native, species. The quantity and diversity of the benthos and plankton says a lot about the quality of the water. With this information we can take measures to improve water quality.