Abstract Anguilliform-swimming fishes (eels, lampreys) are undergoing large and global declines due partly to an inability to pass dams via traditional fishways. The installation of “eel ladders” (wetted, studded/bristle substrates that permit these fishes to climb over obstructions) offer a potential solution. We examined the behaviour of migrating sub-adult sea lamprey (Petromyzon marinus) as they approached and attempted to ascend a 45° studded ramp in a mesocosm placed in a river. We also examined motivation to use the ramp in the presence of a conspecific alarm cue that signals predation risk. Entrance (75%) and attraction efficiency (85%) were high, but reduced by the presence of alarm cue. In total, 98% of sea lamprey attracted to the base of the ramp ascended, and alarm cue had no effect. Time to ascend the ramp (post-release) was variable (1–521 min) and on average was 119 min (50% probability = 35 min). Few sea lamprey required multiple attempts to ascend (19.8%) and was more likely during longer transit times, with multiple ramp attachments, and with higher body mass. Propensity to attach to the ramp increased with number of attempts. The high efficacy of this design, compared to poor-mediocre efficiencies of similar designs in previous studies, may be related to water velocity and depth, geometry of substrate studs, substrate presentation (horizontal/vertical, and incline), and length of studded substrate. Studded ramps represent a substantial opportunity for managers attempting to selectively pass anguilliform fishes over dams, aiding conservation efforts. Applications to the management of sea lamprey include removal in their non-native Great Lakes range, and fish passage in their native range.

中文翻译：

---

海七鳃鳗 (Petromyzon marinus) 过境配备镶嵌基质的坡道：对鱼类通道和入侵物种控制的影响

摘要 鳗状游泳鱼类（鳗鱼、七鳃鳗）正在经历全球范围内的大规模衰退，部分原因是无法通过传统的鱼道通过大坝。安装“鳗鱼梯”（湿润的、带钉的/刚毛的基质，允许这些鱼爬过障碍物）提供了一种潜在的解决方案。我们检查了亚成体海七鳃鳗 (Petromyzon marinus) 的迁徙行为，因为它们接近并试图爬上位于河流中的中间宇宙中的 45° 布满斜坡的斜坡。我们还研究了在发出捕食风险信号的同种警报提示下使用斜坡的动机。入口 (75%) 和吸引效率 (85%) 很高，但由于警报提示的存在而降低。总共有 98% 被吸引到斜坡底部的海七鳃鳗上升，警报提示没有效果。上升斜坡的时间（发布后）是可变的（1-521 分钟），平均为 119 分钟（50% 概率 = 35 分钟）。很少有海七鳃鳗需要多次尝试上升 (19.8%)，并且更有可能在更长的运输时间、多个斜坡附件和更高的体重。附着在斜坡上的倾向随着尝试次数的增加而增加。与之前研究中类似设计的低效率相比，这种设计的高效性可能与水速和深度、基材螺柱的几何形状、基材呈现（水平/垂直和倾斜）以及螺柱基材的长度有关. 对于试图将鳗鱼选择性地通过水坝的管理人员来说，镶嵌坡道代表了一个重要的机会，以帮助保护工作。