Advanced cleaner fish welfare science focuses on matching fish species to environmental conditions where they can be effective and welfare-positive simultaneously.
Advanced cleaner fish welfare science has identified the critical importance of matching species selection to environmental conditions. Deploying lumpfish in water temperatures outside their optimal range causes thermal stress that reduces both their welfare and their efficacy as sea louse control agents — an alignment of welfare and production interests that makes the case for welfare-positive species selection compelling to producers. The welfare requirements of cleaner fish — refuge structures, adequate non-louse feed, appropriate densities, and thermally suitable conditions — are known and achievable. The barrier is treating cleaner fish as disposable pest control tools rather than sentient animals with welfare needs. Regulatory requirements for cleaner fish welfare assessments and minimum provision standards are beginning to address this in Norway and Scotland.