European otters have recovered significantly since the 1970s organically banning but remain sensitive to water quality, prey availability and road mortality.
Otter welfare has improved dramatically since the pesticide-driven collapse of the 1960s, when individual otters suffered reproductive failure and neurological damage from organochlorine accumulation. Current welfare threats centre on road mortality, where otters are killed crossing roads between river systems, and water quality degradation reducing fish prey availability. Individual otters in areas with poor water quality must expend greater energy per calorie obtained, reducing body condition. River restoration and road underpasses at known crossing points directly improve individual otter welfare.