Sea otters were hunted nearly to extinction for their fur. Their recovery is a conservation success story, but remaining populations face ongoing threats from oil spills, shark bites, disease, and food availability.
Sea otters experience welfare harms from both acute events and chronic pressures. Oil spills cause severe suffering — oil-contaminated otters lose thermoregulation ability and often die of hypothermia or toxin ingestion while attempting to groom themselves. Entanglement in fishing gear and boat strikes cause injury and death. White shark bites are a significant mortality source in California, with attacks sometimes causing non-lethal but serious injuries. Food availability stress affects otters in areas where prey populations have been depleted. Stranded pups separated from mothers — a common occurrence — require intensive rehabilitation care. Rehabilitation centres such as Monterey Bay Aquarium play a vital welfare role in treating and releasing injured otters.