The Paddlefish (Polyodon spathula) has been extirpated from portions of its native range due to anthropogenic habitat degradation and fragmentation, most notably the impoundment of rivers. To mitigate some of these losses in Oklahoma, Paddlefish have been stocked into reservoirs throughout the state, with variable success in establishing self-sustaining populations. Two factors thought to contribute to success of Paddlefish stocking are spawning substrate and prey availability, which were quantified in six reservoirs and nine reservoir tributaries. Side-scan sonar and supervised classification of aerial imagery were used to classify 4517-ha of river substrate upstream of the river-reservoir interface in reservoir tributaries. Zooplankton community structure, water clarity, and nutrient availability were also assessed in the same reservoirs and tributaries. One tributary had suitable spawning substrate (>40%), and the rest had minimal (<1.5%), which suggested that availability of suitable spawning substrate was not directly correlated with Paddlefish stocking success. Reservoirs with self-sustaining Paddlefish populations had higher abundance of large zooplankton (copepods and cladocerans) than reservoirs without a reproducing population. Notably, tributaries associated with Lake Texoma, the one known example of failed restoration, were much more turbid than other rivers. We conclude that abiotic factors such as water clarity may contribute more to variable recruitment than spawning substrate or zooplankton abundance by mediating foraging success of Paddlefish post-larvae.

中文翻译：

---

俄克拉荷马州白鲟（Polyodon spathula）恢复成功的相关因素

由于人为栖息地退化和破碎化，特别是河流的蓄水，白鲟（Polyodon spathula）已从其部分原生地区灭绝。为了减轻俄克拉荷马州的部分损失，白鲟被放养到全州各地的水库中，在建立自我维持的种群方面取得了不同程度的成功。人们认为白鲟放养成功的两个因素是产卵基质和猎物可用性，这两个因素在六个水库和九个水库支流中进行了量化。利用侧扫声纳和航空影像监督分类对水库支流河水库界面上游的 4517 公顷河流基质进行了分类。还在相同的水库和支流中评估了浮游动物群落结构、水体透明度和养分可用性。一条支流具有合适的产卵基质（>40%），其余支流的产卵基质很少（<1.5%），这表明合适的产卵基质的可用性与白鲟放养成功与否没有直接关系。具有自我维持白鲟种群的水库比没有繁殖种群的水库具有更高的大型浮游动物（桡足类和枝角类）丰度。值得注意的是，与特克索马湖相关的支流（已知的修复失败的例子之一）比其他河流浑浊得多。我们得出的结论是，水体透明度等非生物因素可能比产卵底物或浮游动物丰度更能促进白鲟幼体觅食的成功。