Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print.
Worldwide declines in salmonid populations have generated major interest in conservation and restoration of wild populations and riverine habitats. Species reintroductions to previous habitats raise questions about their potential impact on these systems. In River Klarälven, landlocked Atlantic salmon (Salmo salar) have been extinct from upper reaches for over 50 years due to hydropower dams. Here we study competitive interactions among juvenile salmon, grayling (Thymallus thymallus), and brown trout (Salmo trutta) that occur in the upper reaches of the river. We examine foraging rates, aggression, and activity of juvenile fish in allopatry at three different densities and in sympatry with one or both potential competitors in laboratory flumes. Salmon captured prey less frequently in the presence of brown trout and grayling, whereas grayling and brown trout were unaffected by salmon, but affected each other. Grayling was the most aggressive and active species, whereas salmon the least. Consequently, reintroduction of salmon probably will have little impact on grayling and brown trout, whereas grayling and brown trout could affect the success of reintroducing salmon.

中文翻译：

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幼体鳟鱼，河鳟和内陆大西洋鲑鱼之间的竞争-预测种间相互作用对鲑鱼再引入成功的影响

《加拿大渔业和水生科学杂志》，印刷前。
世界范围内鲑鱼种群的减少引起了人们对野生种群和河流栖息地的保护和恢复的极大兴趣。将物种重新引入先前的栖息地引发了有关它们对这些系统的潜在影响的疑问。在克拉拉尔文河，由于水力发电大坝，内陆大西洋鲑（Salmo撒拉族）已经从上游灭绝了50多年。在这里，我们研究了在河上游发生的幼鲑，河鳟（Thymallus thymallus）和褐鳟（Salmo trutta）之间的竞争性相互作用。我们以三种不同的密度以及与实验室水槽中的一个或两个潜在竞争者的共生关系，研究了异体混养中幼鱼的觅食率，侵略性和活动性。鲑鱼在鳟鱼和河鳟的存在下捕获猎物的频率降低，而河鳟和鳟鱼则不受鲑鱼的影响，但相互影响。河鳟是最活跃和最活跃的物种，而鲑鱼则最少。因此，鲑鱼的再引入可能对鲑鱼和褐鳟几乎没有影响，而鲑鱼和褐鳟可能会影响鲑鱼再次引入的成功。