Passive Acoustic Monitoring
D5. Coastal processes, sea-level, cryosphere and ocean observation scienceDefinition
Listening with hydrophones to monitor marine life and noise.
Passive acoustic monitoring listens to the underwater soundscape with hydrophones, recording rather than emitting, to detect vocalizing marine mammals, fish choruses, and human noise sources without disturbing the animals. Moored recorders, gliders, and cabled observatories run it for months at a time, and it is the main tool for mapping cetacean presence and quantifying chronic shipping noise. It feeds marine spatial planning, ship-strike avoidance, and the assessment of noise against ambient soundscape baselines.