Normandeau Associates, Inc., Drumore, Pennsylvania, USA.
EDF, Laboratoire National D'Hydraulique et Environnement, Chatou, France.
J Fish Biol. 2019 Nov;95(5):1172-1183. doi: 10.1111/jfb.14115. Epub 2019 Sep 10.
We present the magnitude of losses of European eel Anguilla anguilla and American eel A. rostrata in passage through propeller and Francis turbines at hydroelectric projects. Survival and injury rates and types were turbine type related. Overall, eel survival was higher (mean ± 90% CI = 95.1 ± 5.3%,) and injury rate lower (12.5 ± 10.5) at Francis than propeller turbines (survival = 80.7 ± 6.4%; injury rate = 25.7 ± 7.9%). The common injury type at Francis turbines was bruises and at propeller turbines was severance. Blade shape and thickness of the leading edge of the blades (rounded, thick buckets of Francis turbines v. flatter, sharper edged blades in propeller turbines); eel entry routes into the turbines; their flexible, cylindrical body shape and orientation probably contributed to these differences. Relationship between survival and injury and turbine characteristics was turbine specific. For Francis turbines, one negative correlation (r = -0.986, P < 0.01) between survival and runner speed was found and two positive correlations between injury rates and fish length (r = 0.740, P < 0.10) and number of blades (r = 0.835, P < 0.05) were noted for propeller turbines. Several severely injured eels remained active 48 h after turbine passage suggesting caution is warranted when using telemetric movement for estimating eel survival. We conclude there is a need to (a) better understand travel paths and approach orientation of eels through turbines; (b) determine where only eel passage is of concern at hydropower plants that have both turbine types and therefore preferential operation of Francis turbines may be considered; (c) inform hydropower plant operators where turbine replacement is being considered and downstream eel passage is of concern that replacement by Francis or bulb turbines may prove beneficial for eel passage.
我们展示了欧洲鳗 Anguilla anguilla 和美洲鳗 A. rostrata 在通过水轮机时的损失程度，这些水轮机包括轴流式和混流式水轮机。存活率和受伤率与水轮机类型有关。总的来说，在混流式水轮机中，鳗鱼的存活率更高（平均值±90%置信区间=95.1±5.3%），受伤率更低（12.5±10.5%），而在轴流式水轮机中，鳗鱼的存活率较低（80.7±6.4%），受伤率较高（25.7±7.9%）。在混流式水轮机中，常见的受伤类型是瘀伤，而在轴流式水轮机中，常见的受伤类型是切断。叶片形状和叶片前缘的厚度（混流式水轮机的叶片呈圆形且较厚，而轴流式水轮机的叶片则更平坦且边缘更锋利）；鳗鱼进入水轮机的路径；它们灵活的圆柱形身体形状和方向可能是造成这些差异的原因。存活率和受伤率与水轮机特性之间的关系因水轮机而异。对于混流式水轮机，发现了一个负相关（r = -0.986，P<0.01），即存活率与转轮速度之间的关系，以及两个正相关，即受伤率与鱼的长度（r = 0.740，P<0.10）和叶片数量（r = 0.835，P<0.05）之间的关系，这是针对轴流式水轮机的。一些受重伤的鳗鱼在通过水轮机后 48 小时内仍然活跃，这表明在使用遥测运动来估计鳗鱼的存活率时需要谨慎。我们得出结论，有必要（a）更好地了解鳗鱼通过水轮机的行进路径和接近方向；（b）确定在既有轴流式水轮机又有混流式水轮机的水电站中，哪些地方仅鳗鱼通过是需要关注的；（c）在考虑更换水轮机且下游鳗鱼通过是需要关注的情况下，告知水电站运营商，更换为混流式或灯泡式水轮机可能对鳗鱼通过有利。
