Eurasian otters have made a remarkable comeback in UK rivers following pesticide bans, but still face threats from road mortality, habitat fragmentation, and water quality decline.
Wild otter welfare is shaped by habitat quality and road mortality risk. Riverside habitats degraded by bank reinforcement, agriculture, and development remove the root systems and dense vegetation that provide holts and cover. Otters moving between river catchments cross roads at underpasses and culverts, where road mortality is concentrated. Otter ledges installed in culverts guide animals above water level and significantly reduce mortality at crossing points. River restoration — removing bank revetments, replanting riparian vegetation, and improving water quality — directly improves habitat welfare value for resident otter populations.