Aquaculture Sea Cage Predator Management Welfare

Predator management around sea cage salmon farms involves significant welfare trade-offs between protecting farmed fish and the welfare of wild predators including seals and diving birds.

Key Facts

Grey seals are the primary mammalian predator threat to sea cage salmon farms in the UK, capable of tearing nets and predating large numbers of fish.
Acoustic deterrent devices (ADDs) used to repel seals can cause auditory damage at high intensities and displace seals from important haul-out areas.
Licensed shooting of seals near salmon farms is practiced in Scotland, with hundreds of seals killed annually to protect farm stock.
Non-lethal alternatives including predator nets, improved net pen integrity, and behavioral deterrents are advocated by welfare and conservation organizations.
Diving birds including cormorants and herons can access net pen fish and are often excluded using bird scarers or deterrent netting.

Welfare Considerations

Predator management at sea cage farms creates welfare conflicts between farmed fish, wild seal populations, and other wildlife. Lethal control of seals - which are intelligent, social marine mammals with demonstrated capacity for suffering - for the protection of farmed fish presents a welfare dilemma that the industry and regulators must navigate. The availability of effective non-lethal alternatives - improved net integrity, anti-predator nets, and behavioral deterrents - means that lethal control of seals and other wildlife is increasingly difficult to justify on welfare grounds. Industry standards that require exhaustion of non-lethal measures before licensed lethal control represent a welfare-positive framework.

What You Can Do

Support aquaculture certification schemes that prohibit or restrict lethal predator control.
Advocate for investment in net pen technology that eliminates predator access without deterrents.
Engage with marine conservation organizations monitoring seal population impacts of aquaculture.
Choose salmon from producers with documented non-lethal predator management policies.