Sperm whales live in complex matrilineal societies with cultural transmission across generations; the welfare implications of whaling, noise pollution, and entanglement on these cognitively complex animals are profound.
Sperm whales are among the most cognitively complex animals alive, with social structures, cultural transmission, and likely rich subjective experience. Welfare impacts on these animals deserve serious moral consideration. Sonar exposure has been associated with altered diving behaviour, beaching events, and mass strandings that involve drowning and thermal stress. Entanglement in deepwater fishing gear causes slow death through exhaustion, starvation, and drowning that may extend over days or weeks. Vessel strikes cause traumatic injuries. The disruption of stable social groups through any lethal event affects surviving group members who maintain long-term associations with lost individuals. Chemical pollution concentrating in sperm whale tissue through bioaccumulation causes reproductive and immune dysfunction. The combination of historical depletion and ongoing stressors leaves recovering populations vulnerable to welfare impacts at a species where each individual loss is ecologically and socially significant.