A Novel Marine Mammal Monitoring System Utilizing the Seismic Streamer Spread

There is an increasing concern for the impact of seismic surveys on marine life. In sensitive areas, marine mammal observers are typically present on the vessels. Their task is to visually search in the vicinity of the vessel for marine mammals approaching the source exclusion zone. Due to difficult weather and light conditions, and since mammals may be submerged for long periods, visual detection is often not possible. Passive acoustic monitoring systems is a technology that can assist in detecting and tracking marine mammals. This paper presents a novel integrated system for passive acoustic monitoring, using the streamer hydrophones and seismic acquisition system for localization of marine mammals. The system does not require additional in-sea survey equipment. Beamforming and correlation techniques are used to detect marine mammals. A location is then obtained by inverting wavenumbers and time difference of arrivals. The key advantages of using the streamers is the huge aperture and large number of point receiver hydrophones available. This enables localization with an accuracy better than a few hundred meters. The paper describes the methodology and presents localization examples based on real field data.