This data set provides raw data (abundance/m²) for the benthic macrofauna sampled in 1987 at 66 intertidal (4 TASM 1/32m², sieved on 1mm mesh) and 52 shallow subtidal (5 large Hamon grabs 1/8m², 1 replicat sieved on 2mm mesh and 4 replicats on 5mm mesh) stations located in soft-bottom sediments of the bay of Saint-Brieuc. This data was collected in the scope of the "EUtrophisation et PHénomènes d'ORigne BEnthique (Projet EUPHORBE)" project.