Dams across the Great Lakes basin are nearing or beyond their original design life, posing both challenges and opportunities to natural resource managers. Ageing dams can be repaired to preserve function and maintain safety, removed to promote full connectivity or retrofitted with a fish passage structure to increase connectivity without reservoir loss. The success of rock ramp structures is not well documented, especially for cool‐ and warm‐water fishes in the Great Lakes basin. The success of a recently built (2009) rock ramp for increasing upstream fish passage on the Shiawassee River in Michigan, USA, was evaluated. While there was evidence of limited fish passage during the study period (2011–2016), catches of spring migratory fishes, fish eggs and larvae were significantly higher below the rock ramp than above, indicating the dam with rock ramp fish pass continues to limit upstream migration. Overall connectivity appears improved relative to a reference, dammed river, but falls short of full connectivity.

中文翻译：

---

休伦湖萨吉诺湾支流中冷水和温水鱼的归化岩坡鱼通道评价

五大湖流域的大坝已接近或超出其最初的设计寿命，这对自然资源管理者来说既是挑战也是机遇。老化的大坝可以修复以保持功能和安全，拆除以促进完全连通或改装鱼道结构以增加连通性而不会损失水库。岩石斜坡结构的成功没有得到很好的记录，特别是对于五大湖盆地的冷水和温水鱼类。评估了最近建造的（2009 年）岩石坡道在美国密歇根州 Shiawassee 河上增加上游鱼类通道的成功。虽然在研究期间（2011-2016 年）有证据表明鱼类通过有限，但岩石坡道下方的春季洄游鱼类、鱼卵和幼虫的捕获量明显高于上方，表明带有岩石斜坡鱼道的大坝继续限制上游迁移。整体连通性相对于参考的堤坝河流似乎有所改善，但未达到完全连通性。