Extirpation of Lake Sturgeon in an Ontario Lake Following Dam Construction and Watershed Diversion Confirmed by Indigenous Traditional Knowledge and Sedimentary eDNA.

Damming and water diversions for hydroelectricity, flood control, irrigation, and consumption have had profoundly negative consequences for wildlife, ecosystems, and local peoples globally. The assessment and monitoring of ecological impacts have been common practice for only the last half century and are vital in testing population trends as habitats become increasingly fragmented and degraded. Many systems, including the focus of our study, the Upper Kenogami Watershed (UKW), have been subject to large-scale damming and diversions prior to modern environmental assessments, leaving the consequences largely unknown. Local Anishinaabe communities, Long Lake #58 and Ginoogaming, have long emphasized the many negative consequences for the environment and non-human kin caused by the Upper Kenogami diversion, including the local extirpation of lake sturgeon from Long Lake. Here we find that the extirpation of lake sturgeon from Long Lake coincided with the construction of the Kenogami control dam, evidenced through Indigenous Traditional Knowledge (ITK) within Ginoogaming and Long Lake #58 First Nations, as well as sedimentary eDNA signatures. We thus show how both ITK and molecular insights together reveal a more compelling understanding of the impacts of freshwater entrainment and damming on the UKW lake sturgeon population. We use this information to suggest what is needed to rebuild sustainable populations and relationships.