European river otters recovered from near-extinction following waterway pollution cleanup. Ongoing welfare threats include road mortality and fish depletion.
River otter welfare is closely linked to waterway quality and connectivity. The spectacular recovery from pesticide-driven near-extinction demonstrates that welfare improvements can follow from environmental policy changes. Current welfare threats include road mortality at river crossings without otter passes — simple ledge structures under bridges that allow otters to pass without road crossing are highly effective. Otter spraints (droppings) mark territories and are used to detect occupancy, enabling targeted mortality reduction at road crossings. Ongoing water quality and fish population protection maintains the habitat quality this recovery depends on.