Military sonar exercises have been linked to mass strandings and behavioural disruption in whales and dolphins. The welfare impacts of ocean noise pollution on marine mammals are a growing concern.
Military sonar represents a welfare threat that is difficult to mitigate because it occurs in remote ocean environments, involves classified operations, and affects species whose responses are hard to observe. The evidence linking high-intensity sonar to beaked whale strandings is now strong enough that major navies have implemented mitigation protocols. However, sub-lethal effects — behavioural disruption, masking of communication, altered foraging — are pervasive and affect far more animals than stranding events suggest. The welfare of ocean-going cetaceans is increasingly shaped by anthropogenic noise from multiple sources, including shipping, seismic surveys, and sonar. International agreements, exclusion zones around critical habitats, and mandatory marine mammal observers represent meaningful welfare protections.