Ecological connectivity of invasive and native fishes in a historic navigation waterway

Lockstations in Canada's Rideau Canal Waterway, while not entirely restricting fish connectivity, significantly hinder upstream migration for native species, particularly through multi-flight and higher-lift locks. A three-year acoustic telemetry study (2019–2021) tracked 23 native fishes, including largemouth bass and northern pike, revealing that only 49% of passages occurred through locks, with no detections for invasive common carp. The research suggests that common carp avoid upstream pathways, preferring high-flow areas downstream of dams. Most fish movements were downstream, posing challenges for obligate upstream migrators. This study highlights the complex balance between maintaining native species connectivity and mitigating invasive species spread in regulated waterways.

Bergman, J. N., Bennett, J. R., Minelga, V., Vis, C., Fisk, A. T., & Cooke, S. J. (2024). Ecological connectivity of invasive and native fishes in a historic navigation waterway. Canadian Journal of Fisheries and Aquatic Sciences, 81(5), 600–619. https://doi.org/10.1139/cjfas-2023-0207