This study investigated the biological consequences of 45-day continuous ozonation on Atlantic salmon (Salmo salar) post-smolts in a brackish water recirculating aquaculture system (RAS). There was no significant difference in survival, operational welfare indicators, and average weight at termination between the ozone-treated and control groups. Plasma biochemical analyses revealed that the creatinine level was significantly higher in the ozone-treated group than in the control at termination. Histological evaluation of skin health showed no significant difference between the two groups. On the other hand, quantitative histopathology disclosed that the ozone group exhibited a better gill health status than did the control group, particularly at the end of the trial. Mucosal transcriptomics revealed a distinct response profile between the gills and skin. At day 45, there were no differentially expressed genes (DEG) identified in the skin, in contrast to 242 ozone-induced DEGs in the gills. Assessment of the transcriptomic profiles over time revealed that temporal effects were of greater impact in skin compared to gills, regardless of the treatment. The treatment did not result in metabolomic dysregulation and the overall profile lent support to the transcriptomics data that temporal effects had a greater influence on the changes observed. Exposure to handling-confinement stress revealed that ozone treatment did not alter the ability of post-smolts to respond to a secondary stressor. In summary, the suite of health and welfare indicators collectively indicated that continuous ozonation resulted in minimal physiological perturbations in salmon post-smolts. The results are expected to contribute to optimising the rearing conditions for post-smolts in RAS.

本研究调查了 45 天连续臭氧化对大西洋鲑鱼 ( Salmo salar) 在微咸水循环水产养殖系统 (RAS) 中进行后幼鱼。臭氧处理组和对照组之间的存活率、操作福利指标和终止时的平均体重没有显着差异。血浆生化分析显示，在终止时，臭氧处理组的肌酐水平显着高于对照组。皮肤健康的组织学评估显示两组之间没有显着差异。另一方面，定量组织病理学表明，臭氧组表现出比对照组更好的鳃健康状况，特别是在试验结束时。粘膜转录组学揭示了鳃和皮肤之间的不同反应特征。在第 45 天，皮肤中没有发现差异表达基因 (DEG)，与鳃中的 242 个臭氧诱导的 DEG 形成对比。随着时间的推移对转录组谱的评估表明，与鳃相比，时间效应对皮肤的影响更大，无论治疗如何。治疗没有导致代谢组学失调，整体情况支持转录组学数据，即时间效应对观察到的变化有更大的影响。暴露于处理限制压力表明臭氧处理不会改变后幼崽对次要压力源的反应能力。总之，一系列健康和福利指标共同表明，持续的臭氧化导致鲑鱼幼鱼后的生理扰动最小。预计结果将有助于优化 RAS 中后幼崽的饲养条件。随着时间的推移对转录组谱的评估表明，与鳃相比，时间效应对皮肤的影响更大，无论治疗如何。治疗没有导致代谢组学失调，整体情况支持转录组学数据，即时间效应对观察到的变化有更大的影响。暴露于处理限制压力表明臭氧处理不会改变后幼崽对次要压力源的反应能力。总之，一系列健康和福利指标共同表明，持续的臭氧化导致鲑鱼幼鱼后的生理扰动最小。预计结果将有助于优化 RAS 中后幼崽的饲养条件。随着时间的推移对转录组谱的评估表明，与鳃相比，时间效应对皮肤的影响更大，无论治疗如何。治疗没有导致代谢组学失调，整体情况支持转录组学数据，即时间效应对观察到的变化有更大的影响。暴露于处理限制压力表明臭氧处理不会改变后幼崽对次要压力源的反应能力。总之，一系列健康和福利指标共同表明，持续的臭氧化导致鲑鱼幼鱼后的生理扰动最小。预计结果将有助于优化 RAS 中后幼崽的饲养条件。