Development, validation and testing of an Operational Welfare Score Index for farmed lumpfish Cyclopterus lumpus L

Lumpfish (Cyclopterus lumpus L.) are widely used for controlling sea lice in salmon farming, but their welfare is often challenged by poor husbandry, stress, and disease outbreaks, which compromise ability to delouse cause public concern. It hence important identify when the of lumpfish being compromised a simple effective manner so that remedial actions can be taken. We developed, validated tested Operational Welfare Score Index (LOWSI) based on visual assessment skin fin damage, eye condition, sucker deformities relative weight, operational indicators fish farmers considered most informative were against cortisol measurements. also present percentile length-weight charts enable detect underweight emaciated at different stages development. The lumpish score index was quick easy highly repeatable (intra class correlation coefficient = 0.83 ± 0.05). Most (71%) displayed good welfare, significant differences found between six commercial sites 28% had lower than normal weights length, 10% emaciated. common problems damage hatcheries, condition body cages, conditions may increase risk emaciation. Being able quickly accurately will help improve reduce stress-related mortalities, sustainability farming industry.