River otters were extirpated from much of their historical range but are recovering in many areas through pollution control and targeted reintroduction.
River otters caught in traps suffer significantly - leg-hold traps cause pain and distress for the duration of capture, which may be extended if traps are not checked frequently. Otters caught in conibear (body-gripping) traps intended for other species experience unintended bycatch mortality. Entanglement in fishing gear causes drowning. Oil spills coat otter fur, destroying its insulating properties and causing hypothermia and ingestion of toxins during grooming. The recovery of river otters in cleaned waterways represents both a conservation success and an improvement in the welfare of ecosystems and the many species they support.