Bycatch of common dolphins (Delphinus delphis) in fishing nets is one of the main threats to this species in the Bay of Biscay. Strandings of common dolphins showing signs of fishing gear are observed every winter on the French Atlantic coast, highlighting the scale of the species' bycatch.

The APOCADO project (Acoustique Passive pour l'Observation des Captures Accidentelles de Dauphins communs), led by ENSTA, aims to document net/common dolphin interactions using passive acoustics. The protocol consists of equipping the fishing gear of volunteer netters with autonomous acoustic recorders (SoundTrap ST400HF, Ocean Instrument). The recorders are attached directly to the net. Each recording corresponds to one fishing operation (OP), defined as the complete duration of the net being set (shooting), the soaking period, and up until retrieval (hauling). The project initially focused on Breton netters, which show another peak of strandings with signs of capture in summer. The protocol was then extended to the entire Atlantic coast with the help of partners such as regional fisheries committees, producer organizations, and marine nature parks.