Freshwater fish in natural water bodies face welfare threats from pollution, water abstraction, physical barriers to migration, and angling, with river restoration offering significant welfare co-benefits alongside ecological recovery.
Freshwater fish welfare is affected by multiple simultaneous stressors in many UK rivers. Pollution from agriculture and sewage suppresses oxygen levels and increases toxicant loads. Water abstraction reduces flows and concentrates remaining pollutants. Physical barriers prevent migration to spawning grounds, creating reproductive failure and population decline. Angling causes acute stress through capture, air exposure, and handling, with some evidence of prolonged physiological impact even after careful release. River restoration through fish pass installation, riparian planting, and pollution control improves welfare by restoring natural habitats and reducing chronic stressors.