This dataset contains a curated collection of plankton images acquired with the Plankton Imager Pi-10 exclusively in the Belgian Part of the North Sea (BPNS). The images are organized in taxon-specific folders and are intended for the development, training and validation of automated image-classification models supporting plankton monitoring and pelagic ecosystem assessments. Particular attention is given to the reliable discrimination of taxa and broader plankton lifeforms relevant to assessments conducted within the framework of the OSPAR Convention.