Sea otters were hunted to near-extinction and have recovered in some areas. Their welfare faces ongoing threats from pollution, disease, and human disturbance.
Sea otter welfare is shaped by their unusual dependence on fur for thermoregulation — unlike other marine mammals, sea otters lack blubber and rely entirely on their fur's insulating properties. Oil contamination of fur destroys this insulation, causing life-threatening hypothermia that requires immediate intensive rehabilitation if an animal is to survive. The Exxon Valdez spill killed thousands of sea otters through this mechanism, demonstrating the catastrophic welfare impact of oil spills on this species. Toxoplasmosis, contracted from domestic cat faeces washed into coastal waters, causes neurological disease and death in sea otters — a striking example of the welfare connection between domestic animal management and wild animal welfare. Entanglement in fishing gear causes drowning that is preventable through modified trap designs.