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International audience; Orcas (Orcinus orca) can produce 3 types of signals:clicks, whistles and vocalizations. This study focuses onorca vocalizations from northern Vancouver Island (Han-son Island) where the NGO Orcalab developed a multihy-drophone recording station to study orcas. The acousticstation is composed of 5 hydrophones and extends over 50km2of ocean. Since 2015 our team is continuously stream-ing the hydrophone signals, yielding nearly 50 TB of syn-chronous multichannel recordings. We trained a Convolu-tional Neural Network (CNN) to detect orca vocalizations,by transfer learning from a bird activity dataset. We re-late the detected presence and absence of the orca vocal-izations to the time of the day, the moon phases and thetides. This real-time detector opens new insight on thesestreamed submarine recording, allowing online automaticsurvey of the orca in the whole area. It thus assess in whicharea the orcas are present. It then could be used to monitorthe effect of traffic pressure and anthropophonic pollutionon this species. We finally discuss towards the installationof small quadraphonic system acoustic device to completeand detail these observations from Orcalab, in order to getmore precise relative positions of the orcas.

International audience; One of the best ways of studying animals that produce signals in underwater environments is to use passive acoustic monitoring (PAM). Acoustic monitoring is used to study marine mammals in oceans, and gives us information for understanding cetacean life, such as their behaviour, movement or reproduction. Automated analysis for captured sound is almost essential because of the large quantity of data. A deep learning approach was chosen for this task, since it has proven great efficiency for answering such problematics. This study focused on the orcas (Orcinus orca) of northern Vancouver Island, Canada, in collaboration with the NGO Orcalab which developed a multi-hydrophone recording station around Hanson Island to study orcas. The acoustic station is composed of 5 hydrophones and extends over 50 km 2 of ocean. Since 2016 we are continuously streaming the hydrophone signals to our laboratory at Toulon, France, yielding nearly 50 TB of synchronous multichannel recordings. The objective for this research is to do a preliminary analysis of the collected data and demonstrate influence of environmental factors (tidal, moon phase and daily period) on the orcas' acoustic activities.