River otters and sea otters face welfare challenges from habitat loss, oil spills, prey depletion, and pollution that compromise both individual health and population viability.
Otter welfare is shaped by the health of their aquatic habitats. Oil spill contamination is among the most dramatic acute welfare crises: otters whose fur is coated in oil lose its insulating properties and face hypothermia even in cool water. They ingest oil while grooming, causing internal organ damage. River otters face chronic pollution from agricultural runoff, heavy metals, and persistent organic compounds that affect reproduction and immune function. Prey depletion from overfishing forces sea otters to dive more frequently and further, increasing energetic demands. Habitat protection and pollution reduction are the foundation of otter welfare at a population scale.