Restoring stream connectivity by replacing road culverts is a high conservation priority, yet long-term fish passage data aimed to “ground-truth” culvert prioritization methods are lacking. One common tool for prioritizing culvert removals is the protocol developed by the North Atlantic Aquatic Connectivity Collaborative (NAACC), which uses culvert characteristics to estimate barrier severity and fish passage. To determine the degree to which NAACC scoring reflects trout passage, we monitored Brook Trout Salvelinus fontinalis movements through three culverts and a reference site (no culvert) in a central Pennsylvania watershed. Passage was nearly continuously monitored for 16 months using remote stationary PIT tag readers. We found that NAACC ranks underestimated Brook Trout passage through two of three culverts. Specifically, the culvert with a rank of “reduced aquatic organism passage (AOP)” experienced higher rates of upstream passage (up to 10 upstream movements per day) than all other sites combined, including the reference site. The reduced AOP site also had a similar proportion of the tagged population that moved upstream (20.9%) compared to the reference site (16.9%). Of the two remaining culverts, both box culverts rated as “no AOP,” one had almost no upstream passage (only two upstream movements over the entire study) and the other had passage rates similar to the reference stream (up to four upstream movements per day). Brook Trout tended to move during high flow and the fall spawning period. We suggest that, for the streams considered in our study, the NAACC protocol may better predict upstream passage if it emphasizes culvert type and adjusts measurement thresholds in the AOP coarse screening. If these patterns are supported by studies at other locations, a more nuanced treatment of culvert type and outlet characteristics in NAACC protocols may more accurately predict Brook Trout passage through culverts.

中文翻译：

---

道路涵洞的布鲁克鳟鱼通道与宾夕法尼亚州源头溪流的大尺度评估标准的比较

通过更换道路涵洞恢复河流连通性是一个高度保护优先事项，但缺乏旨在“地面真实”涵洞优先排序方法的长期鱼类通道数据。北大西洋水生连通性协作组织 (NAACC) 开发的协议是一种用于优先考虑涵洞清除的常用工具，该协议使用涵洞特征来估计屏障严重程度和鱼类通过。为了确定 NAACC 评分反映鳟鱼通过的程度，我们监测了 Brook Trout Salvelinus fontinalis穿过宾夕法尼亚州中部流域的三个涵洞和一个参考点（无涵洞）的运动。使用远程固定 PIT 标签阅读器几乎连续监测了 16 个月的通道。我们发现 NAACC 排名低估了通过三个涵洞中的两个涵洞的布鲁克鳟鱼通道。具体而言，具有“减少水生生物通过 (AOP)”等级的涵洞的上游通过率（每天最多 10 次上游移动）高于所有其他地点（包括参考地点）的总和。与参考站点 (16.9%) 相比，减少的 AOP 站点也有相似比例的标记种群向上游移动 (20.9%)。在剩下的两个涵洞中，两个箱涵都被评为“无 AOP，”一个几乎没有上游通道（在整个研究中只有两次上游移动），而另一个的通过率与参考流相似（每天最多四次上游移动）。溪鳟鱼在高流量和秋季产卵期倾向于移动。我们建议，对于我们研究中考虑的河流，如果 NAACC 协议强调涵洞类型并调整 AOP 粗筛中的测量阈值，则它可以更好地预测上游通道。如果这些模式得到其他地点的研究的支持，NAACC 协议中对涵洞类型和出口特征的更细致处理可能会更准确地预测布鲁克鳟鱼通过涵洞的通道。对于我们研究中考虑的河流，如果 NAACC 协议强调涵洞类型并调整 AOP 粗筛中的测量阈值，则它可以更好地预测上游通道。如果这些模式得到其他地点的研究的支持，NAACC 协议中对涵洞类型和出口特征的更细致处理可能会更准确地预测布鲁克鳟鱼通过涵洞的通道。对于我们研究中考虑的河流，如果 NAACC 协议强调涵洞类型并调整 AOP 粗筛中的测量阈值，则它可以更好地预测上游通道。如果这些模式得到其他地点的研究的支持，NAACC 协议中对涵洞类型和出口特征的更细致处理可能会更准确地预测布鲁克鳟鱼通过涵洞的通道。