Sea Cage Fish Welfare: Environmental Challenges

Open sea cage aquaculture presents specific welfare challenges related to weather, sea lice, predators and environmental variability.

Key Facts

Atlantic salmon in sea cages experience water temperatures from 2 to 20 degrees across a year
Jellyfish bloom events cause gill damage requiring emergency cage management
Predator exclusion nets protect against seals but can trap and drown marine mammals if not managed
Storm events can structurally damage cages causing crowding stress and escapes
Sea lice are the most persistent welfare challenge in open sea cage salmon production

Welfare Considerations

Open sea cage welfare is subject to the variability of the natural marine environment in ways that land-based or recirculating systems are not. Weather events, temperature changes, jellyfish blooms and algal events create welfare challenges that require rapid management response. The exposure to natural variation can be welfare-positive (natural current, light cycles) or welfare-negative (harmful temperature extremes, pathogens). Managing sea cage welfare requires anticipating natural events, maintaining equipment that prevents welfare-damaging incidents and monitoring fish welfare continuously to detect early signs of stress from environmental challenges.

What You Can Do

Support sea cage regulations requiring emergency response plans for weather and environmental events
Advocate for predator exclusion net management standards preventing marine mammal entanglement
Choose salmon from certified operations with documented environmental welfare management protocols
Support research into sea cage design and management reducing vulnerability to environmental welfare challenges