Agricultural runoff causes nutrient pollution, algal blooms, and chemical contamination that devastates aquatic animal welfare in rivers, lakes, and coastal waters.
Agricultural runoff welfare is chronic and acute simultaneously. Chronic pollution degrades habitat quality for aquatic animals over decades. Acute events — slurry spills, fertiliser runoff pulses — cause rapid oxygen depletion and mass fish kills. Fish dying in hypoxic water surface and gasp — a distress response visible over large areas. The welfare impact of major river pollution events can affect millions of individual animals. Agricultural practices that reduce runoff — buffer strips along waterways, precision fertiliser application, cover cropping, constructed wetlands — are welfare interventions as much as environmental ones. Consumer demand for sustainably farmed food incentivises adoption of these practices.