Evaluating American Eel Seasonal Habitat Relationships in the Upper St. Lawrence River in Relation to Ongoing Recovery Efforts

Recently, a comprehensive review of the status of the American eel (Anguilla rostrata) in Ontario waters established a number of recovery objectives and recommendations, including the identification and protection of critical habitat for this species.  Specific habitat associations in Ontario are currently not well understood and may include areas that are vulnerable to modification from human activities and climate change.  We investigated the seasonal movements and habitat associations of juvenile (yellow-phase) eels in Lake St. Francis, a fluvial lake in the Upper St. Lawrence River (USLR) with the highest remaining abundance of wild eels in Ontario. A combined approach of radio-telemetry, electrofishing, and trap-netting was used examine the relationships between eel distributions and environmental features within the study area from 2013 to 2014, and was supplemented by anecdotal reports from local fishing and SCUBA diving organizations.   Preliminary results from electrofishing surveys indicate significant abundance and size-based trends in relation to proximity to a large hydroelectric facility and bottom substrate types, respectively, while radio-telemetry results indicate that larger eels (70-100 mm TL) are highly mobile within this river reach.  The results of this ongoing research project are discussed in terms of potential applications to ongoing recovery activities in the USLR.