New Zealand's chinook salmon industry produces premium export products in the Marlborough Sounds, with welfare challenges from sea lice, crowding, and increasing water temperatures under climate change.
Chinook salmon welfare in New Zealand marine cages is increasingly challenged by water temperatures that approach the species thermal tolerance limits during summer, causing heat stress with physiological and welfare consequences. Sea lice infestations cause skin damage and potentially secondary infections if left untreated, but treatment itself causes stress. Crowding in cages prevents the species natural wide-ranging swimming behaviour. Climate change is making thermal stress more frequent and severe, potentially pushing farming operations to deeper, cooler water sites. Proactive welfare monitoring including welfare scoring at grading events and temperature-triggered management responses are best practice welfare tools.