Data is an assembly of plankton monitoring stations situated between 54° and 58° North along the Danish coasts and in estuaries. There are 6 zooplankton stations that are visited 6 times per year. Samples are analyzed to estimate zooplankton composition and abundance. The individuals are either sized or staged and species is determined to lowest possible taxonomical level. This dataset includes multicellular prokaryotes as well as ciliates and same heterotrophic dinoflagellates