Cataracts affect the majority of farmed Atlantic salmon, causing significant visual impairment and welfare harm that dietary prevention can substantially reduce.
Salmon cataracts represent a welfare failure that is simultaneously widespread, well-understood, and preventable. Vision impairment in a fish whose survival, feeding, and predator avoidance all depend on visual processing is a significant welfare harm. Chronically cataractous fish feed less effectively, experience more panic episodes during husbandry procedures, and likely have qualitatively poorer lives than clear-sighted conspecifics. The dietary fix is known and economically accessible — the barrier to implementation is industry inertia and the absence of regulatory requirements. This is exactly the type of preventable welfare harm that certification standards and regulatory requirements can most effectively address.