Eurasian otters have recovered remarkably across much of Europe following bans on organochlorine pesticides and hunting, but face continued threats from road mortality, water pollution, and habitat degradation.
Otter welfare is intimately linked to water quality and river habitat integrity. Pollution events cause acute mortality and chronic illness as otters bioaccumulate contaminants through their fish-heavy diet. Road death at poorly designed culverts and bridges traps otters trying to cross roads following river courses — a simple design problem with straightforward engineering solutions. Cubs that lose their mothers before achieving fishing independence face starvation. The remarkable recovery of otter populations across Europe demonstrates what clean water legislation and hunting bans can achieve, and provides a model for species recovery through addressing root causes of population decline.