Anthropogenic noise from shipping, sonar, seismic surveys and construction fills the ocean and causes documented welfare harms to whales, dolphins and other marine mammals.
Noise pollution causes welfare harm to cetaceans across a spectrum from acute acoustic trauma to chronic stress from communication masking. Military sonar events have caused documented mass strandings where beaked whales surface rapidly in panic response to sonar signals, causing decompression-like injuries and death. This represents acute, severe welfare harm to multiple individuals in a single event. Chronic shipping noise masks the long-distance communication that whales use for social contact, mate location and coordinated foraging. Animals in noisier ocean regions show elevated stress hormones. Welfare responses include speed restrictions for vessels in sensitive areas, seasonal sonar exclusion zones during whale calving, and mandatory noise assessment in offshore development permits.