Sea otters as keystone species maintaining kelp forest ecosystems provide ecosystem services that benefit thousands of other species.
Sea otters that ingest toxic algae blooms, suffer from shark bites, or become entangled in fishing gear experience significant welfare harm. Their extremely high metabolic rates mean that any injury or illness rapidly becomes life-threatening. The complete dependence on fur insulation means oil spills are catastrophically harmful. Individual sea otters play outsized ecological roles, making their welfare disproportionately important.