Migratory delay leads to reduced passage success of Atlantic salmon smolts at a hydroelectric dam.
Migratory delay leads to reduced passage success of Atlantic salmon smolts at a hydroelectric dam.
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迁徙延迟导致大西洋鲑鱼在水力发电大坝的通过成功率降低。
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
T. Castro‐Santos
中科院分区：
文献类型：
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作者：
D. Nyqvist;L. Greenberg;E. Goerig;O. Calles;E. Bergman;W. R. Ardren;T. Castro‐Santos
鱼类通过水电站大坝与洄游鱼类的死亡率、延迟、增加的能量消耗和洄游失败有关，人们广泛认识到需要对上游和下游的洄游采取补救措施。一个功能性的鱼道必须确保安全和及时的通道，很大一部分洄游鱼类将使用。通道解决方案不仅要解决成功通过障碍的鱼类数量或百分比，还要解决通过障碍所需的时间。在这里，我们使用无线电遥测研究下游迁移野生捕捞和孵化场释放的大西洋鲑鱼小鲑鱼的鱼类旁路的功能。我们使用时间-事件分析来模拟鱼类特征和环境变量对与大坝通过相关的一系列事件发生率的影响。在模拟的事件中，旁路入口区的接近率，前池和入口区的滞留率和通过率。尽管多次尝试，只有65%的标记鱼在前池通过大坝。鱼通过旁路（33%），通过溢出（18%）和通过涡轮机（15%）。出院的方法，通过和保留率呈正相关。我们没有发现野生和孵化场鱼之间的任何差异。尽管个别鱼多次访问前湾和入口区，但大多数鱼在第一次暴露于这些区域时通过。这项研究强调了及时性的重要性，通过成功和有用的时间到事件的分析，了解因素，通过性能。
Passage of fish through hydropower dams is associated with mortality, delay, increased energy expenditure and migratory failure for migrating fish and the need for remedial measures for both upstream and downstream migration is widely recognised. A functional fish passage must ensure safe and timely passage routes that a substantial portion of migrating fish will use. Passage solutions must address not only the number or percentage of fish that successfully pass a barrier, but also the time it takes to pass. Here, we used radiotelemetry to study the functionality of a fish bypass for downstream-migrating wild-caught and hatchery-released Atlantic salmon smolts. We used time-to-event analysis to model the influence of fish characteristics and environmental variables on the rates of a series of events associated with dam passage. Among the modelled events were approach rate to the bypass entry zone, retention rates in both the forebay and the entry zone and passage rates. Despite repeated attempts, only 65% of the tagged fish present in the forebay passed the dam. Fish passed via the bypass (33%), via spill (18%) and via turbines (15%). Discharge was positively related to approach, passage and retention rates. We did not detect any differences between wild and hatchery fish. Even though individual fish visited the forebay and the entry zone on multiple occasions, most fish passed during the first exposures to these zones. This study underscores the importance of timeliness to passage success and the usefulness of time-to-event analysis for understanding factors governing passage performance.