Sea otters are a keystone species that maintain kelp forest ecosystems by controlling sea urchin populations, making their conservation essential for both ecological function and individual welfare.
Sea otters face welfare threats from both acute and chronic sources. Oil spill victims experience rapid hypothermia as contaminated fur loses insulating properties; cleaning and rehabilitation is intensive and stressful for affected animals. Shark bite wounds, though usually non-fatal, cause significant trauma and infection risk. Domoic acid poisoning from harmful algal blooms causes seizures, neurological damage, and death in affected otters. Fishing gear entanglement causes drowning and injuries. The physiological demands of sea otter thermoregulation mean that nutritional stress from prey depletion quickly becomes life-threatening. Individual welfare and ecosystem function are deeply linked for this species: healthy kelp forests provide the invertebrate prey density that sea otters need to survive, while sea otters maintain the kelp forests by suppressing urchin overgrazing. Protecting sea otters protects the entire ecosystem they inhabit.