Sea otters are among the few non-primate tool users, using rocks to crack hard-shelled prey — a behavior with implications for understanding animal cognition and welfare.
Sea otter welfare is tightly linked to ecological integrity. Their fur — the densest of any mammal — provides all thermal insulation, making oil contamination immediately life-threatening. The Exxon Valdez spill killed approximately 2,800 sea otters directly, with population-level effects lasting decades. Chronic oil exposure from small spills is harder to detect but causes cumulative welfare harm. Entanglement in fishing gear causes drowning. Harmful algal blooms driven by agricultural runoff cause domoic acid poisoning, triggering neurological seizures and death. As recovered populations expand their range northward with warming oceans, human-otter conflicts over shellfish harvesting create pressure for lethal management. Protecting sea otter welfare requires addressing pollution, entanglement, harmful algal blooms, and conflict management simultaneously.