Wild dolphins face growing threats from ocean pollution, underwater noise, and entanglement. These human-caused stressors affect individual welfare and population health across species worldwide.
Wild dolphin welfare is under sustained assault from multiple anthropogenic stressors that individually and cumulatively affect individual and population health. Chemical pollution through PCBs, mercury, and microplastics causes chronic immune suppression, reproductive failure, and developmental abnormalities. Acoustic pollution from increasingly busy shipping lanes, seismic surveys, and military sonar causes masking of natural communication that disrupts feeding, social behavior, and navigation. Individual dolphins entangled in fishing gear experience distress, injury, and in many cases slow death from drowning. The cumulative welfare burden on wild dolphin populations living in highly impacted coastal waters — where multiple stressors overlap — represents a chronic welfare crisis at population scale. The baiji extinction in the Yangtze River demonstrates the endpoint of unmitigated anthropogenic pressure. Policy solutions including whale sanctuaries, shipping speed restrictions, and fishing gear modifications have documented effectiveness in reducing individual and population welfare harm.