State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu 610065, China.
State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing 210029, China.
Int J Environ Res Public Health. 2022 May 9;19(9):5744. doi: 10.3390/ijerph19095744.
The damming of the river changes the structure of the original river ecosystem, and although fish passage plays an important role in maintaining the connectivity of the river ecosystem, the fish have difficulty finding the fish passage entrance during the upstream process. This paper studied the rheotaxis of fish under three different water flow conditions experimentally through recirculating water tanks. To better understand the response of Crucian carp () to water flow stimulation, the representative swimming trajectory, sensing success rate, attraction success rate, reaction time, and attraction time of the fish were analyzed by using a video monitoring system. The experimental results showed that fish responded differently to single-peak and lateral bimodal outflow conditions: (1) the single-peak outflow condition had a much better attraction effect than the lateral bimodal outflow condition, both in terms of sensing success rate and attraction success rate; (2) the fish swam mainly in the middle area of the lateral bimodal outflow condition, while the fish swam more evenly in the single-peak outflow condition. Therefore, setting the attraction current at the right time and near the entrance of the fish passage may help to improve the effect of fish attraction.
河流筑坝改变了原有河流生态系统的结构，虽然鱼类洄游在维持河流生态系统连通性方面起着重要作用，但鱼类在上溯过程中很难找到鱼类洄游通道入口。本研究通过循环水槽实验，对三种不同水流条件下鱼类的趋流性进行了研究。为了更好地理解鲫鱼对水流刺激的响应，采用视频监测系统分析了鱼类的代表性游动轨迹、感应成功率、吸引力成功率、反应时间和吸引力时间。实验结果表明，鱼类对单峰和侧向双峰流出条件的反应不同：（1）单峰流出条件比侧向双峰流出条件具有更好的吸引力效果，无论是感应成功率还是吸引力成功率；（2）鱼类在侧向双峰流出条件下主要在中间区域游动，而在单峰流出条件下鱼类游动更均匀。因此，在适当的时间和鱼类洄游通道入口附近设置吸引水流可能有助于提高鱼类吸引效果。
