Department of Hydraulic and Environmental Engineering, Norwegian University of Science and Technology, Trondheim, Norway.
J Fish Biol. 2012 Jul;81(2):642-63. doi: 10.1111/j.1095-8649.2012.03363.x. Epub 2012 Jun 25.
In this study, cost effective (in terms of reducing loss of power production) measures for increasing bypass migration of Atlantic salmon Salmo salar were developed and tested by establishing statistical models for timing of smolt migration and favourable diversion of water to the bypass. Initial tracking of radio-tagged smolts showed very low bypass migration under normal hydropower operations. Bypass migration increased when bypass discharge was experimentally increased and a model was developed that described relationships between total river discharge, bypass diversion and smolt migration route. Further improvements were obtained by installing two strobe lights at the power-production tunnel entrance that increased bypass migration during the night, but not during daytime. According to the behaviour of radio-tagged fish, the implemented measures contributed to increasing the annual percentage of bypass migration from 11 to 64%, and according to model predictions to 60-74% when the hydropower facilities were operated according to the developed models. To ensure correct timing of discharge diversion a smolt migration model was developed based on environmental variables that could successfully predict the general pattern of migration timing. The concept presented for improving smolt migration past hydropower intakes should be applicable in many systems where migration past hydropower installations cannot easily be solved by screening systems.
在这项研究中，我们开发并测试了一些具有成本效益（即减少发电损失）的措施，以增加大西洋三文鱼（Salmo salar）的洄游旁路迁移，这些措施是通过建立关于洄游时间和有利的旁路引水的统计模型来实现的。最初对标记过的幼鱼进行追踪显示，在正常水力发电运行下，旁路迁移的数量非常低。当实验性地增加旁路排放量时，旁路迁移增加了，并且建立了一个模型来描述总河流量、旁路引水和幼鱼洄游路径之间的关系。通过在发电隧道入口处安装两个频闪灯进一步提高了旁路迁移，这两个频闪灯在夜间增加了旁路迁移，但在白天不会增加。根据标记过的鱼类的行为，实施的措施有助于将每年的旁路迁移率从 11%提高到 64%，根据模型预测，当根据开发的模型运行水力发电设施时，每年的旁路迁移率将达到 60-74%。为了确保正确的排放引水时间，我们根据环境变量开发了一个幼鱼洄游模型，该模型可以成功预测迁移时间的一般模式。提出的用于改善洄游鱼类通过水力发电设施的概念，应该适用于许多通过水力发电设施无法通过筛选系统轻易解决的洄游鱼类迁移的系统。
