Temporal distribution of the number of polychaete records in the Mediterranean Sea present in the Ocean Biogeographic Information System (OBIS) and new contributions by the MidMedPol dataset. Only records from OBIS that contain information about the collection year were included, and data from before 1960 were omitted for reasons of clarity. a number of records for all depths, b number of records in the depth range of 0–5m. Diagrams based on the data from Suppl. material