Ocean Noise Pollution and Cetacean Welfare

Anthropogenic ocean noise from shipping, sonar and seismic surveys causes chronic stress, communication disruption and physical injury in whales and dolphins.

Key Facts

Ocean ambient noise levels have doubled every decade since 1950, primarily from commercial shipping traffic
Military sonar exercises have been linked to mass strandings of beaked whales — sonar appears to cause decompression-like injuries as whales surface too rapidly
Blue whales now call at lower frequencies than 50 years ago, likely to be heard above shipping noise — a documented adaptive response
Shipping noise reduces the effective communication range of North Atlantic right whales by over 60% in areas of high traffic
Seismic surveys for oil and gas use air-guns producing sounds up to 250 decibels — among the loudest human-made underwater sounds
Shipping speed reduction of just 10 knots reduces vessel noise by approximately 40% and collision risk substantially

Welfare Considerations

Cetaceans rely on sound for virtually everything that matters to their survival and social lives — navigation, foraging, mating, mother-calf communication and predator detection. Chronic noise pollution degrades all these capacities simultaneously. The welfare consequences range from communication disruption and foraging impairment to physical injury from intense acoustic events and chronic stress reflected in elevated glucocorticoid levels in noise-exposed populations. Noise pollution is a pervasive, increasing and underregulated threat to cetacean welfare. Speed reductions for shipping in critical habitat, mandatory exclusion zones for seismic surveys near cetacean aggregations, and sonar reforms are achievable policy interventions.

What You Can Do

Support policies mandating vessel speed reductions in areas with high cetacean density and shipping traffic
Advocate for seismic survey exclusion zones around known cetacean feeding and breeding aggregations
Back regulatory reform of military sonar exercises in shallow coastal waters used by beaked whales
Choose seafood from fisheries with low associated shipping noise impacts in critical cetacean habitat
Learn about ocean noise pollution and share it to expand the constituency for marine acoustic welfare