Aquaculture

Wrasse as Cleaner Fish: A Deep Welfare Dive

Comprehensive welfare analysis of cleaner wrasse used for sea lice control in salmon farming.

Key Facts

Cleaner wrasse (primarily Labrus bergylta, L. mixtus, and Ctenolabrus rupestris) are used in salmon cages to remove sea lice
Over 50 million wrasse are used annually in Norwegian salmon farming alone
Wild-caught wrasse are under pressure -- sustainable aquaculture production of wrasse is being developed
Wrasse welfare is often neglected -- mortality rates of 50-70% or more are reported in some operations
Wrasse are subtropical-adapted fish being kept in cold sub-Arctic Norwegian waters -- chronic cold stress is a significant welfare concern
They require complex habitat including rocky substrate and kelp for shelter and refuge from salmon
Wrasse cannot easily escape salmon if startled -- salmon attacks on wrasse cause injury and death
Lumpfish are also used as cleaner fish -- their welfare needs differ significantly from wrasse

Welfare Significance

Cleaner fish welfare represents one of the most overlooked welfare problems in aquaculture. Millions of wrasse die prematurely in salmon farms annually from cold stress, salmon attacks, and inadequate habitat provision. Their welfare needs -- warmth, complex habitat, refuge from predators -- cannot easily be met in salmon cage environments. Using them as tools without addressing their welfare needs is ethically unjustifiable given their evident sentience as vertebrate fish.

What You Can Do

Advocate for welfare standards specifically for cleaner fish in salmon aquaculture certification
Support development of alternative biological and non-biological sea lice control methods that reduce cleaner fish dependence
Ask certified salmon producers about their cleaner fish mortality rates and welfare provisions
Support research into cleaner fish welfare needs and ways to meet them in commercial salmon farming