Spawning behaviour of the Lake Sturgeon (Acipenser fulvescens) in large rivers is poorly understood, complicating the approach to fish‐friendly hydroelectric design and mitigation. In 2006, dam safety concerns prompted the need to modernize the spillway infrastructure of the 100‐year old Pointe du Bois Generating Station on the Winnipeg River, Manitoba. The associated regulatory process provided an opportunity to study Lake Sturgeon spawning in a location characterized by water depths >5 m, high velocities, and hydraulic instability. Over six spawning periods (2007–2012), a wide range of flow conditions occurred, and spawning was documented using egg mats in both the powerhouse tailrace and downstream of the spillway rapids. Herein, we consider “….the preferential utilization by sturgeon of certain ranges of the physical variables studied, but within habitats considered favourable for the reproduction of the species” conclusion forwarded by La Haye et al. as our working hypothesis. Overall, 27,362 of 30,085 (90.1%) Lake Sturgeon eggs were captured during the primary spawning intervals, defined based on 6‐day annual periods encompassing the date of peak deposition. Of the 2,200 mats retrieved, 74.4% captured 0 eggs, 12.0% captured 1–5 eggs, 5.2% captured 6–25 eggs, 6.1% captured 26–99 eggs, and just 2.2% captured ≥100 eggs (high‐yield). Data were examined in relation to status‐quo habitat variables (depth, velocity, and substrate), as well as two additional variables hypothesized to have predictive power: distance from physical and/or energetic barriers and hydraulic complexity. Distance‐based analyses revealed upstream to downstream redistribution of eggs via flow. Spawning (as inferred based on high‐yield mats) was spatially discrete during each spawning period as opposed to well‐distributed among habitats broadly considered to be suitable for the species. We suggest that the current‐edges located proximal to physical and/or energetic barriers (i.e., at the upstream extent of usable habitat) drive Lake Sturgeon spawning site selection in large rivers, and advise caution prior to making fine‐scale inferences when only small quantities of Lake Sturgeon eggs are captured.

中文翻译：

---

基于卵沉积研究的关于St鱼湖产卵在大河水力发电站下方的观测

人们对understood鱼湖（Acipenser fulvescens）在大河中的产卵行为知之甚少，这使得鱼友好型水力发电设计和缓解方法变得复杂。2006年，出于对大坝安全的担忧，对马尼托巴省温尼伯河上已有100年历史的Pointe du Bois发电站的溢洪道基础设施进行了现代化改造。相关的监管程序为研究St鱼湖产卵提供了机会，in鱼产卵的水深大于5 m，流速较高，水力不稳定。在六个产卵期（2007-2012年），发生了各种各样的水流状况，并且在动力舱尾水道和溢洪道急流下游使用卵垫记录了产卵情况。在此，我们考虑“……。st鱼在一定范围内优先利用所研究的物理变量，但在被认为有利于该物种繁殖的栖息地内La Haye等人提出的结论。作为我们的工作假设。总体上，在主要产卵间隔期间捕获了30,085个湖urge鱼卵中的27,362个（占90.1％），卵的产卵间隔是根据包括高峰沉积日期在内的每年6天的年定义的。在回收的2200个垫子中，74.4％捕获了0个卵，12.0％捕获了1–5个卵，5.2％捕获了6–25个卵，6.1％捕获了26–99个卵，只有2.2％捕获了≥100个卵（高产）。检查了与栖息地现状变量（深度，速度和底物）以及两个假设具有预测能力的变量有关的数据：距物理和/或能量屏障的距离以及水力复杂性。基于距离的分析显示了鸡蛋通过流动从上游到下游的重新分布。在每个产卵期间，产卵（根据高产地垫推断）在空间上是离散的，与在广泛认为适合该物种的生境中分布良好相反。我们建议，位于物理和/或能量屏障近端（即，在可用栖息地的上游范围）的当前边缘驱动大河中St鱼湖产卵地点的选择，并建议在小规模推断之前进行细微推断。捕获了大量的St鱼湖卵。