Atlantic salmon populations in many rivers have declined to historically low levels, and individual fish welfare is affected by habitat degradation, barriers to migration, and ocean feeding failures.
Individual salmon welfare during the migratory lifecycle is affected at multiple points by human modification of rivers and the ocean. Fish exhausting themselves attempting to pass impassable barriers suffer physiologically before dying. Kelts in post-spawning condition are immunologically compromised and face extended stress from fishing capture and handling. Heat stress from warming rivers causes acute suffering before mortality. Conservation actions that restore migration routes, reduce angling mortality under thermal stress conditions, and protect marine feeding areas directly benefit individual fish welfare alongside population recovery.