Sea otters play a critical ecological role as keystone species in kelp forest ecosystems. Their welfare and conservation are inseparably linked to the health of Pacific coastal ecosystems.
Sea otter welfare encompasses individual animal health needs and population-level conservation without which the species cannot thrive. Individual welfare challenges include domoic acid toxicosis from harmful algal blooms, great white shark bite injuries, and entanglement in fishing gear. The species' high metabolic demands mean that nutritional stress is a persistent welfare concern, particularly for females nursing pups. Oil spill response is a critical welfare intervention — oiled otters face hypothermia and toxicosis without rapid capture and treatment. At the population level, the continued range restriction of sea otters far below historical numbers represents a welfare deficit at ecosystem scale. Recovery programs that expand otter populations into suitable habitat improve both individual welfare and ecosystem health.