Aquaculture Mortality Removal and Welfare

Prompt removal of mortalities from aquaculture systems is essential for fish welfare, biosecurity and water quality, yet is often inadequate in commercial operations.

Key Facts

Mortality removal in sea cage salmon production is challenging due to cage size and depth
Accumulated dead fish cause water quality deterioration that stresses surviving fish
Delayed mortality removal creates conditions favourable for disease transmission to live fish
Automated mortality counting and retrieval systems are being developed for offshore and nearshore cage systems
Mortality rates are a key welfare indicator in aquaculture and should be recorded and reported regularly

Welfare Considerations

The failure to promptly remove mortalities from aquaculture systems is both a welfare indicator and a welfare multiplier. High mortality rates indicate existing welfare problems, while unremoved mortalities worsen water quality and disease pressure on surviving fish, compounding welfare harm. The logistical challenges of mortality removal in large sea cage systems are genuine but must be addressed through technological innovation and management investment. Regular, transparent mortality reporting is a minimum welfare accountability requirement.

What You Can Do

Support development of automated mortality detection and removal technology for aquaculture
Advocate for mandatory mortality recording and regular public reporting for all aquaculture operations
Choose certified aquaculture products where mortality rates are disclosed as part of welfare reporting
Engage with aquaculture certification bodies about strengthening mortality reporting requirements
Support research into the welfare implications of different mortality levels and removal intervals