Sea otters are a keystone species whose recovery has transformed kelp forest ecosystems, but individual otter welfare involves significant challenges including shark predation, domoic acid poisoning, and reproductive stress.
Sea otter welfare encompasses both individual animal experiences and the ecosystem-level consequences of their conservation. At the individual level, sea otters live demanding lives: their extremely high metabolic rate means that any reduction in foraging success — from injury, illness, domoic acid exposure, or prey depletion — quickly becomes life-threatening. Shark bites that leave otters alive but injured cause prolonged suffering before recovery or death; the Monterey Bay Aquarium has pioneered rehabilitation for injured otters. Domoic acid events cause visible, distressing neurological symptoms — seizures, head tremors, disorientation — before death. At the population level, the recovery of sea otters has restored kelp forest ecosystems across much of their range through predation on sea urchins, creating habitat for hundreds of marine species. This ecosystem function represents enormous indirect welfare value for the diverse animals that inhabit kelp forests. Protecting sea otter populations thus serves both individual and ecosystem-wide welfare objectives.