Investigating the impacts of lice prevention technologies on lumpfish welfare and grazing efficiency
The objective of this trial is to investigate how several lice prevention technologies which are utilized in commercial salmon production impact the welfare and effectiveness of lumpfish (Cyclopterus lumpus).
Millions of lumpfish are deployed by the Norwegian Atlantic salmon industry annually, but they alone are insufficient to remove the need for delousing treatments on many farms. One promising idea is to combine cleanerfish with lice prevention measures, with the aim that cleanerfish can remove any lice which reach the salmon. Unfortunately, however, little is known about how lice prevention measures affect lumpfish welfare and effectiveness. This research aims to determine which lice prevention measures can be used simultaneously with lumpfish without negatively impacting welfare or grazing efficiency.
We will run 3 experiments at the Austevoll Research Station operated by Havforskningsinstituttet in which lumpfish are stocked with salmon in cages with and without several lice prevention measures, including skirts, snorkels, deep lights and deep feeding. There will be nine 12x12x12m cages, each stocked with 6000 salmon smolts (Nsalmon =54,000). Lumpfish will be stocked in each cage at a density of 10%. The lumpfish must be sampled and replaced in each experiment, so a total of 600 lumpfish per cage x 9 cages x 3 experiments = 16,200.
To acurately mimic commercial production conditions, replacement of live animal usage is not possible. We have, however, reduced the number of animals as much as possible while still maintaining commercial relevance and achieving a controlled and replicated experimental design. The trial must be run in at least 12x12 cages, because the impacts and effectiveness of lice prevention technologies differ with cage size, and any smaller would not be relevant to large commercial cages. In 12x12 cages, 6000 salmon will give us an initial stocking density of 0.5 kg/m3, which is the lowest stocking density used on farms, and there must be sufficient density to interact with the lumpfish. Lumpfish will be stocked at 10%, which is the recommended density used commercially. By removing all lumpfish at the end of each experiment, we are able to keep the same salmon, thereby minimizing the total number of animals required whilst still getting results directly applicable to industry.
Through refinement of all procedures, the level of distress for all fish is expected to be minimal. All fish will be maintained using best known husbandry practices. Ambient environmental conditions will be monitored daily throughout the trial, and oxygen saturation within cages while prevention measures are in place. Behavior and physical condition of salmon and lumpfish will also be monitored throughout. The only stressor for any of the fish is handling, which will be required for transfer into the cage and at final sampling, and PIT tagging of the lumpfish. Anesthesia will be used for all handling events, including tagging, transfer and sampling.
The results from this trial will minimize lumpfish losses on commercial farms, and will move us one step closer to a commercially viable lice management strategy which removes the need for stressful handling and delousing operations.
Millions of lumpfish are deployed by the Norwegian Atlantic salmon industry annually, but they alone are insufficient to remove the need for delousing treatments on many farms. One promising idea is to combine cleanerfish with lice prevention measures, with the aim that cleanerfish can remove any lice which reach the salmon. Unfortunately, however, little is known about how lice prevention measures affect lumpfish welfare and effectiveness. This research aims to determine which lice prevention measures can be used simultaneously with lumpfish without negatively impacting welfare or grazing efficiency.
We will run 3 experiments at the Austevoll Research Station operated by Havforskningsinstituttet in which lumpfish are stocked with salmon in cages with and without several lice prevention measures, including skirts, snorkels, deep lights and deep feeding. There will be nine 12x12x12m cages, each stocked with 6000 salmon smolts (Nsalmon =54,000). Lumpfish will be stocked in each cage at a density of 10%. The lumpfish must be sampled and replaced in each experiment, so a total of 600 lumpfish per cage x 9 cages x 3 experiments = 16,200.
To acurately mimic commercial production conditions, replacement of live animal usage is not possible. We have, however, reduced the number of animals as much as possible while still maintaining commercial relevance and achieving a controlled and replicated experimental design. The trial must be run in at least 12x12 cages, because the impacts and effectiveness of lice prevention technologies differ with cage size, and any smaller would not be relevant to large commercial cages. In 12x12 cages, 6000 salmon will give us an initial stocking density of 0.5 kg/m3, which is the lowest stocking density used on farms, and there must be sufficient density to interact with the lumpfish. Lumpfish will be stocked at 10%, which is the recommended density used commercially. By removing all lumpfish at the end of each experiment, we are able to keep the same salmon, thereby minimizing the total number of animals required whilst still getting results directly applicable to industry.
Through refinement of all procedures, the level of distress for all fish is expected to be minimal. All fish will be maintained using best known husbandry practices. Ambient environmental conditions will be monitored daily throughout the trial, and oxygen saturation within cages while prevention measures are in place. Behavior and physical condition of salmon and lumpfish will also be monitored throughout. The only stressor for any of the fish is handling, which will be required for transfer into the cage and at final sampling, and PIT tagging of the lumpfish. Anesthesia will be used for all handling events, including tagging, transfer and sampling.
The results from this trial will minimize lumpfish losses on commercial farms, and will move us one step closer to a commercially viable lice management strategy which removes the need for stressful handling and delousing operations.