Green sea turtles have recovered substantially in some populations following protection, but face a debilitating tumour disease linked to water pollution that is spreading across tropical populations worldwide.
Green turtle welfare in coastal waters degraded by agricultural pollution faces a specific and severe threat: fibropapillomatosis. Turtles with advanced tumours cannot see clearly, swim efficiently, or feed adequately. Tumours grow on eyes, flippers, and throat, impairing basic survival functions. The disease is chronic and progressive, causing prolonged welfare harm before death. The link to nitrogen pollution from agriculture means that consumer choices and agricultural policy directly influence disease prevalence. Coastal water quality improvement is both a direct welfare intervention for green turtles and a benefit to the broader marine ecosystem. Rehabilitation provides welfare relief for individual animals but cannot address the population-level disease burden without upstream pollution reduction.