Biomass of plankton groups and presence records of the most important species related to the oyster farming which were present in the Sluice Dock between 1960 and 1964. The data were digitized by VLIZ from the original reports: Leloup, E. et al. Recherches sur l'ostréiculture dans le bassin de chasse d'Ostende. Ministère de l'Agriculture. Commission TWOZ. Groupe de Travail Ostréiculture: Ostende.