Anthropogenic underwater noise from shipping, sonar, and construction causes hearing damage, behavioral disruption, and welfare harm to marine mammals and fish.
Marine mammals that rely on sound for communication, navigation, and foraging are disproportionately affected by underwater noise. Beaked whales that strand following naval sonar exercises show gas embolism in tissues consistent with a rapid ascent response triggered by acute acoustic disturbance. Chronic shipping noise extends the time whales spend calling, reducing time available for foraging. Fish can be permanently deafened by proximity to pile driving. Mitigation measures including vessel slowdowns, exclusion zones, and bubble curtains around pile driving can significantly reduce acoustic impact.