Gray whales undertake one of the longest migrations of any mammal, traveling up to 20,000 kilometers annually between Arctic feeding grounds and Mexican lagoon breeding areas, with welfare implications across the entire route.
Gray whale welfare during migration is challenged by the accumulation of threats along a 20,000-kilometer route. Each kilometer of coastline carries different human pressures — fishing gear entanglement in northern feeding areas, ship traffic near major ports, and coastal development noise across the entire route. Individual whales must navigate these threats over months of continuous travel, often while fasting. Domoic acid events can strand individuals far from their migration route in states of neurological crisis. Ship strike survivors may carry propeller injuries that impair their ability to complete migration and feed effectively. The welfare dimension of gray whale migration is primarily about maintaining the safety of the migration corridor — creating ship speed zones, transitioning from pot fishing gear to ropeless alternatives, and monitoring for toxin events that require rescue response.