Sea otters are charismatic keystone predators of kelp forest ecosystems whose recovery from near-extinction is a conservation success story. Their ongoing welfare threats include oil spills, shark predation, and the precariousness of slow population recovery.
Sea otter welfare is intimately connected to the health of kelp forest ecosystems. When sea urchin populations explode — as they do when otter numbers fall — kelp forests collapse into urchin barrens, eliminating the habitat structure that supports diverse marine life including the fish and invertebrates otters depend on. Individual sea otter welfare is most acutely threatened by oil spills: contaminated fur loses insulating capacity rapidly, causing hypothermia in an animal that cannot survive without effective fur insulation. Oil spill response for sea otters — involving capture, intensive cleaning, and rehabilitation — is welfare-positive but stressful for individuals undergoing it. Shark bite wounds, which have increased as white shark populations recover in California, cause severe injuries that are sometimes survivable with veterinary intervention. Maintaining clean oceans, preventing oil spills, and ensuring adequate prey availability are the primary welfare imperatives for this keystone species.