Animal Welfare Research Group, Institute of Marine Research, Matredal 5984, Norway.
Bremnes Seashore AS, Øklandsvegen 90, 5430 Bremnes, Norway; Department of Biology, University of Bergen, 5006 Bergen, Norway.
Prev Vet Med. 2020 Aug;181:105063. doi: 10.1016/j.prevetmed.2020.105063. Epub 2020 Jun 18.
Ectoparasitic salmon louse (Lepeophtheirus salmonis) infestations are costly for Atlantic salmon (Salmo salar) farmers in Norway. As a result, there is a strong desire for solutions to prevent and control infestations, and new technologies are typically developed and commercialised rapidly, without rigorous validation. Here, we tested the efficacy of a new commercially available control measure-delousing by underwater lasers-using a replicated design at full commercial scale. Laser delousing was used in combination with a preventive method (snorkel cages), with laser nodes deployed in 3 of the 6 sea cages at the site. The trial ran for 54 days, after which time there was no difference in infestation density of mobile salmon louse stages (pre-adult, adult male or adult female) in cages with or without laser nodes installed. By the end of the trial, adult female lice numbers in all cages were close to the legislated trigger for mandatory delousing (0.5 adult female lice per fish). The laser nodes delivered a large number of pulses relative to the number of lice in the cages, indicating that a lack of lethality rather than a lack of target detection was the limiting factor. If all pulses had been effective, they should have removed between 4-38 % of mobile lice each day. There was no effect on salmon welfare indicators such as skin condition or eye status. Our results highlight the importance of rigorous validation of new technologies across a range of conditions before widespread implementation by industry.
寄生性鲑鱼虱（Lepeophtheirus salmonis）的侵害给挪威的大西洋鲑鱼（Salmo salar）养殖户带来了巨大的经济损失。因此，人们强烈希望找到预防和控制感染的方法，而新技术通常会在没有严格验证的情况下迅速开发和商业化。在这里，我们采用完全商业化的规模，在复制设计中测试了一种新的商业上可用的控制措施——水下激光除虱的效果。激光除虱与预防方法（潜水笼）相结合，在现场的 6 个海水笼中的 3 个中部署了激光节点。试验持续了 54 天，之后在有无激光节点安装的笼子中，移动的鲑鱼虱阶段（未成熟、成年雄性或成年雌性）的感染密度没有差异。试验结束时，所有笼子中的成年雌性虱数量都接近强制性除虱的法定触发值（每鱼 0.5 只成年雌性虱）。激光节点相对于笼子中的虱子数量发射了大量脉冲，表明缺乏杀伤力而不是缺乏目标检测是限制因素。如果所有脉冲都有效，它们每天应该可以去除 4-38%的移动虱子。对鲑鱼的福利指标如皮肤状况或眼睛状况没有影响。我们的结果强调了在行业广泛实施之前，对新技术在各种条件下进行严格验证的重要性。
