North American river otters have recovered in many states after near-extirpation, but remain dependent on clean rivers and wetlands that face continuing pressures from pollution, trapping, and development.
River otter welfare is an integrative measure of riparian ecosystem health. Otters that find adequate fish populations in clean water can maintain the playful, active behavior characteristic of this species. Malnourished otters in depleted or polluted watersheds show reduced social play and increased foraging time at the expense of other welfare-positive behaviors. The recovery of river otters in states where they were reintroduced demonstrates that waterway cleanup and wildlife protection together enable the restoration of functional welfare alongside ecological function.