Recruitment is an important driver of fish population abundance and size structure and can be affected by a variety of density‐dependent and density‐independent factors. Walleye Sander vitreus populations often exhibit variable year‐class strength, which has been attributed to a suite of factors. In this study, we quantified variability in Walleye recruitment, assessed within‐lake recruitment synchrony, and modeled recruitment variability for year‐classes that were produced from 1988 to 2013 in Lake Oahe, a large Missouri River reservoir. The objectives of this study were to determine (1) whether Walleye recruit annually, (2) whether Walleye recruitment is spatially synchronous, and (3) whether Walleye recruitment is better described by biotic or abiotic factors. The variability of Walleye recruitment was indexed by using gill‐net catch of age‐2 Walleye across nine locations in Lake Oahe, and factors affecting recruitment were evaluated by using stock–recruit analysis. Over the 26 years that were assessed, all year‐classes were present and four exceptionally large year‐classes were produced. Recruitment synchrony was apparent among locations within Lake Oahe, but this relationship was largely influenced by the spatial synchrony of the four exceptionally large year‐classes and was no longer detectable when those year‐classes were removed. The relative abundance of age‐4 and older Walleye, taken as an index of spawner abundance, was a poor predictor of Walleye recruitment, indicating that Walleye recruitment was regulated by density‐independent factors across the range of observations. The interactive effects of reservoir elevation and elevation change improved model fit to explain 59% of the recruitment variation and indicated that increased elevation from the previous year improved recruitment. Our results indicate that Walleye recruitment may be favored by increasing the water levels in the reservoir in spring.

中文翻译：

---

密苏里河瓦河湖水库海拔和空间同步对角膜白质募集的影响

招聘是鱼类种群丰度和大小结构的重要驱动因素，并可能受到各种密度依赖和密度独立因素的影响。角膜白斑玻璃体人口经常表现出不同的年级强度，这归因于一系列因素。在这项研究中，我们量化了Walleye募集的可变性，评估了湖内募集的同步性，并对1988年至2013年在密苏里州大型水库奥阿湖生产的年级的募集可变性进行了建模。这项研究的目的是确定（1）Walleye每年是否招募，（2）Walleye招募在空间上是否同步，以及（3）Walleye招募是否可以用生物或非生物因素更好地描述。通过使用Oahe湖中9个地点的2岁角膜白斑的刺网捕捞，对角膜白斑募集的变异性进行了指数化，并通过使用种群补充分析对影响招聘的因素进行了评估。经过26年的评估，所有的年级都在场，并制作了四个特别大的年级。奥阿湖内各地区之间的招聘同步很明显，但是这种关系在很大程度上受四个特别大的年级的空间同步的影响，而当这些年级被删除时，这种关系就不再可察觉。4岁和较老的角膜白斑的相对丰度被视为产卵体的丰度指标，对角膜白斑募集的预测较差，这表明角膜白斑的募集受到观察范围内密度无关因素的调节。储层标高和标高变化的交互作用改善了模型拟合度，可以解释59％的募集量变化，并表明与上一年相比标高的增加改善了募集量。