This dataset is the result of census exercises made by students in the framework of the Marine Biology Excursions Course, at the Universite Libre de Bruxelles (ULB). The data includes occurrence from the intertidal zone, taken on a yearly basis (by different batches of students), for which identifications are systematically checked by the supervisors. The field work focuses on transects chosen in the the Bay of Wimereux (Pas-de-Calais, France) which are oriented towards contrasted ecological gradients.