This dataset is part of the historic monitoring campaign onboard of the lightship West-Hinder. Temperature, salinity & alkalinity were measured daily. At the same time plankton samples were taken. The presences/absences for plankton samples were recovered by ICES. The quantitative data could not be found, but zooplankton counts for 1902 were published in Van Meel 1975. La Mer du Nord méridionale, le Pas-de-Calais et la Manche: essai d'écologie marine, principalement en ce qui concerne le microplancton: II. Etude planctonique. Data were digitized by VLIZ in the frame of the LifeWatch project.