Freshwater fish represent an enormous and largely ignored welfare population facing threats from pollution, dam construction, overfishing, and climate change affecting billions of individuals globally.
If freshwater fish have capacity for suffering - as growing scientific evidence suggests - then the 83 percent population decline represents an immense welfare catastrophe affecting species diversity across thousands of lakes, rivers, and streams. Fish caught in hypoxic zones created by agricultural runoff experience the distress of oxygen deprivation. Fish blocked below dams cannot complete their migratory spawning drives, representing frustrated biological imperatives in species with strong migratory instincts. Fish affected by warming water temperatures experience thermal stress and physiological strain before dying from heat. The scale of freshwater fish welfare concerns, measured against their likely sentience, represents one of the largest and most underaddressed welfare issues in conservation.