Data from: Physical, physiological, and reproductive effects on adult fall Chinook Salmon due to passage through a novel fish transport system

Movement past hydroelectric dams and related in-river structures has important implications for habitat connectivity and population persistence in migratory fish. A major problem is that many of these structures lack effective fish passage facilities, which can fragment spawning and rearing areas and negatively impact recruitment. While traditional fish passage facilities (e.g., ladders, trap and haul) can effectively enable fish to pass over barriers, their capital or operational costs can be significant. We evaluated the utility of a novel transport device that utilizes a flexible tube with differential internal air pressure to pass fish around in-river barriers. A total of N = 147 adult fall Chinook salmon (Oncorhynchus tshawytscha) nearing maturation were apportioned to three treatments and a control group. In two of the treatments, adult fall Chinook salmon were transported through the device via two lengths of tube (12 or 77 m) and their injury, stress, and immune system responses and reproductive function were compared to a third treatment where fish were moved by a standard trap and haul method and also to a control group. We observed no significant differences among the treatment or control groups in post-treatment adult survival, injury or stress. Indicators of immune system response and reproductive readiness were also not significantly different among the four groups. Egg survival was significantly different among the groups, with the highest survival in the eggs from females transported 77 m and lowest in the control group; the differences were highly variable within groups and not consistent with the duration of treatment or degree of handling. Taken together, the results suggest the device did not injure or alter normal physiological functioning of adult fall Chinook salmon nearing maturation and may provide an effective method for transporting such fish around in-river barriers during their spawning migration.

洄游鱼类通过水电大坝及相关河道内构筑物的过程，对其栖息地连通性与种群存续具有重要意义。当前的核心问题在于，多数此类拦河构筑物未配备有效的过鱼设施（fish passage facilities），这会割裂鱼类的产卵与育幼生境，并对其资源补充量产生负面影响。尽管传统过鱼设施（如鱼道（fish ladder）、诱捕转运法（trap and haul））可有效帮助鱼类翻越拦阻设施，但其建设成本与运维成本往往较高。本研究评估了一种基于内部气压差驱动的柔性管（flexible tube with differential internal air pressure）新型鱼类转运装置的应用效果，该装置可帮助鱼类绕行河道拦阻设施。研究共选取N=147尾临近性成熟的秋季大鳞大麻哈鱼（Oncorhynchus tshawytscha），将其分为3个处理组与1个对照组。其中2个处理组的秋季大鳞大麻哈鱼通过两种不同长度（12米与77米）的柔性管完成转运；第三个处理组采用标准诱捕转运法进行鱼类转移，同时设置空白对照组。本研究对比了各组鱼类的损伤情况、应激反应、免疫响应与生殖功能。研究结果显示，各处理组与对照组的处理后成鱼存活率、损伤程度及应激水平均无显著差异；四组样本的免疫响应指标与生殖就绪度也未呈现显著区别。各组间的鱼卵存活率存在显著差异：经77米柔性管转运的雌鱼所产卵的存活率最高，对照组鱼卵存活率最低；但组内差异幅度较大，且该差异与转运时长或操作强度并无一致性关联。综合来看，该新型转运装置未对临近性成熟的秋季大鳞大麻哈鱼造成损伤或改变其正常生理机能，可为产卵洄游过程中此类鱼类跨河道拦阻设施的转运提供一种高效可行的方案。