Floating guidance structures are intended to promote safe passage for juvenile salmon migrating downstream through reservoirs. However, the ability of an engineered structure to guide fish to safe passage has been primarily tested through large‐scale implementation in reservoirs or in laboratory studies and computer simulations without live fish. Research is needed that integrates fluid mechanics with fish behaviour to study how hydraulic conditions around a guidance structure trigger swimming behaviours. In this study, an outdoor experimental channel was used to identify: (a) the hydraulic signature of a floating guidance structure and (b) changes in fish swim behaviour in relation to channel hydraulics. The flow field surrounding a guidance structure at two deployment angles was characterized using acoustic Doppler velocimeters. Swimming behaviours of juvenile Chinook salmon were recorded using underwater videogrammetry. A statistical method for behaviour change detection identified the most likely locations of swimming behaviour changes in fish as they first encountered the guidance structure. Finally, the locations of behaviour changes were compared to the hydraulics surrounding each guidance structure. Taken together, results indicated the fish did respond to the guide wall with behaviour changes, but did not distinguish between the two guide wall angles. While the two guide wall angles did produce statistically different distributions of hydraulic variables, the differences were small, potentially too small for the fish to produce a behavioural response. To inform the design of guidance structures, further work may clarify if swim responses vary with more aggressive wall angles and/or higher approach velocities, or if any contraction of flow and/or visual cue will produce similar behaviour responses.

中文翻译：

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奇努克鲑鱼漂浮导向结构的水力和游泳响应实验

浮动的引导结构旨在促进幼鲑通过水库向下游迁移的安全通道。但是，主要通过在水库中或在没有活鱼的情况下的实验室研究和计算机模拟中大规模实施工程​​结构来引导鱼类安全通过的能力。需要进行将流体力学与鱼类行为相结合的研究，以研究引导结构周围的水力条件如何触发游泳行为。在这项研究中，使用室外实验通道来识别：（a）浮动导向结构的水力特征，以及（b）与通道水力有关的鱼游泳行为变化。使用声学多普勒测速仪表征了在两个展开角周围的引导结构周围的流场。使用水下录像测量法记录了奇努克鲑鱼的游泳行为。一种用于行为变化检测的统计方法，可以确定鱼类在首次遇到引导结构时游泳行为变化最可能的位置。最后，将行为变化的位置与每个导向结构周围的液压系统进行了比较。两者合计，结果表明鱼确实对行为变化的导向壁做出了响应，但没有区分两个导向壁角度。虽然两个导向壁的角度确实产生了水力变量的统计上不同的分布，但差异很小，对于鱼类而言可能太小而无法产生行为响应。为了指导结构的设计，