Sea otters are keystone species whose fur provides their only insulation against cold water. Oil spills destroy this fur, causing hypothermia and death — one of the most severe acute welfare events for marine mammals.
Oil spill deaths are particularly distressing for sea otters. Hypothermia from oiled fur causes shivering, weakness, and progressive organ failure over hours to days. Animals that survive initial oiling suffer during capture and the intensive cleaning process — which is essential but stressful. Internal toxin exposure from grooming causes additional suffering. The vulnerability of sea otters to oil spills — their complete dependence on clean, intact fur — means that spill prevention is the primary welfare intervention. Strong pipeline safety regulations, tanker double-hulling requirements, and rapid response capacity all directly reduce the frequency and severity of this welfare harm.