Funding information State Agency for Nature, Environment and Consumer Protection of North RhineWestphalia (LANUV); Ministry for Climate Protection, Environment, Agriculture, Conservation and Consumer Protection of the State of North Rhine-Westphalia (MKULNV) Abstract Weirs are barriers built across rivers for a wide range of other purposes than hydropower production. Like hydropower installations, weirs can negatively impact fish migrations. Downstream migration and mortality of Atlantic salmon smolts were studied during passage of a weir and power station by tagging 227 smolts with radio transmitters. Extra loss of smolts due to the weir and adjacent reservoir was 5.2%. Mortality was likely related to physical damage imposed to the smolts and/or increased predation risk. Extra loss of smolts did not differ between the weir and the power station (7.2%). Migration speeds were reduced at the power station but not at the weir. We conclude that mortality at one power station site may differ considerably among years, because the mortality was more than four times higher in a previous year than in this study. Increased river discharge seemed to decrease mortality and increase migration speeds at the power station.

中文翻译：

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堰和发电站对德国河流下游迁移的大西洋鲑鱼的影响

资金信息 北莱茵威斯特法伦州自然、环境和消费者保护国家局 (LANUV)；北莱茵-威斯特法伦州气候保护、环境、农业、自然保护和消费者保护部 (MKULNV) 摘要 堰是跨河流建造的屏障，用于除水电生产之外的其他广泛用途。像水电装置一样，堰会对鱼类洄游产生负面影响。通过用无线电发射器标记 227 条小鲑鱼，在通过堰和发电站期间研究了大西洋鲑小鲑鱼的下游迁移和死亡率。由于堰和邻近的水库造成的黑鲱额外损失为 5.2%。死亡率可能与对幼崽造成的物理伤害和/或增加的捕食风险有关。堰和发电站之间的额外幼鱼损失没有差异（7.2%）。发电站的迁移速度降低了，但堰处没有。我们得出结论，一个电站站点的死亡率可能会因年份而异，因为前一年的死亡率是本研究的四倍多。河流流量的增加似乎降低了死亡率并增加了发电站的迁移速度。