The recovery of otters in UK rivers following the ban on organochlorine pesticides represents one of the UK's most significant wildlife welfare success stories, linked directly to improved water quality across river systems.
Otter recovery demonstrates the direct connection between environmental pollution and individual animal welfare. Otters accumulating organochlorine pesticides suffered reproductive failure and possibly neurological damage before population collapse. The welfare improvement from pesticide bans is difficult to quantify but represents the elimination of a major source of toxic harm to individual animals. Current welfare threats include road mortality, which causes acute traumatic death, and illegal persecution by fisheries interests, which while less common than historically, still represents a welfare concern. Continued water quality improvement supports otter population health and individual welfare.