Cetacean Acoustic Pollution and Welfare

Underwater noise pollution from shipping, sonar, and industrial activity causes chronic stress and disrupts communication and navigation in whales and dolphins with significant welfare implications.

Key Facts

Shipping noise has increased ambient ocean sound levels by 32 decibels over the past 50 years
Blue whales have shifted their song frequency downward since the 1960s, possibly in response to noise masking
Naval sonar exercises have been directly linked to mass strandings of beaked whales since the 1990s
Chronic noise exposure elevates cortisol in cetaceans and disrupts mother-calf acoustic communication
The International Maritime Organization has issued voluntary guidelines for reducing ship noise but compliance is limited

Welfare Considerations

Cetaceans that communicate, navigate, and hunt through sound experience acoustic pollution as a pervasive sensory environment degradation. Noise masking disrupts mother-calf contact calls, interferes with echolocation precision in dolphins, and forces blue whales to shift calling frequencies that have been stable for millions of years. Chronic noise stress elevates cortisol, suppresses immune function, and interferes with reproductive behavior. The welfare harm from ocean noise pollution is ongoing, large-scale, and growing with shipping traffic — making it one of the most significant wildlife welfare issues receiving least attention.

What You Can Do

Support IMO mandatory noise reduction standards for commercial shipping
Advocate for ship speed reductions in critical cetacean habitat as a low-cost noise reduction measure
Oppose new high-intensity sonar exercises near known cetacean aggregation areas
Support ocean noise monitoring programs that provide data for regulatory action