Three-dimensional hydrodynamic numerical simulation and laboratory fish-passage experiment with juvenile grass carp (Ctenopharyngodon idella) were used to systematically estimate hydrodynamic parameters, fish passage efficiency, fish swimming behavior, and fish swimming trajectories in a vertical-slot fishway (VSF) under five different flow discharges. The spatial-mean time-averaged velocity magnitude along the slot section determined passage success rate. The absolute value of the time-averaged Reynolds-shear-stress component in the X–Y direction played a decisive role in selecting the swimming path. In addition, fish energy expenditure along the mean-50% swimming route indicated that higher mainstream velocity did not necessarily signify larger energy consumption, because successfully-migrating fish selected the relatively lower velocity zone during the migration process. Our findings for fish swimming behavior in response to velocity and turbulence can be used to develop high-efficiency fishways for grass carps or other species with similar traits.

中文翻译：

---

垂直槽鱼道鱼通过效率、鱼游动行为和水力特性之间的关系

采用三维水动力数值模拟和室内草鱼幼鱼通过实验，系统地估算了垂直槽鱼道（VSF）的水动力参数、鱼的通过效率、鱼的游动行为和鱼的游动轨迹。五种不同的流量排放。沿槽截面的空间平均时间平均速度大小决定了通过成功率。X - Y方向的时间平均雷诺剪应力分量的绝对值在选择游泳路径时起着决定性作用。此外，鱼类沿平均50%游动路线的能量消耗表明，较高的主流速度并不一定意味着较大的能量消耗，因为成功洄游的鱼类在洄游过程中选择了相对较低的速度区域。我们对鱼类游动行为对速度和湍流的响应的研究结果可用于为草鱼或其他具有类似特征的物种开发高效鱼道。