Sperm whales are the world's largest toothed predators with extraordinary cognitive and social complexity. Their welfare is threatened by ship strikes, entanglement, acoustic pollution, and plastic ingestion.
Sperm whale welfare encompasses the acute and chronic threats faced by one of the ocean's most cognitively sophisticated animals. Their cultural societies — where knowledge including specific foraging techniques is transmitted across generations through social learning — make disruption of social groups not just an ecological concern but a welfare harm to socially and cognitively complex beings. Ship strikes cause immediate severe trauma. Military sonar exercises have been linked to mass strandings where whales swim into shallow water to escape acoustic injury — dying of dehydration and physical trauma on beaches. Entanglement in deep-set fishing gear causes injury and drowning. Plastic ingestion — documented in sperm whales found dead containing stomach-compacting masses of plastic waste — causes starvation through gastric obstruction. Chronic acoustic pollution from commercial shipping disrupts the echolocation-based foraging that sperm whales depend on for food in lightless deep-ocean environments. Climate change is altering the distribution of giant squid prey, affecting foraging success in already-challenging deep-ocean environments.