Monitoring the Migration of American Eel in the Beauharnois Canal of the Upper St. Lawrence River Using Acoustic Telemetry

Knowledge of silver American eel migration patterns are essential to determine mitigation options related to turbine mortality at hydroelectric dam. In 2012, we studied the spatio-temporal migration pattern of 88 silver American eel using acoustic telemetry in a 25 km canal upstream of the Beauharnois Generating Station in Québec, Canada. Silver American eel started their migration in June, peaked in July-August and end in September. Most of the migration occurred at night. Two behavioral pattern were observed with most eel exhibiting a rapid straightforward downstream migration. The second pattern was a slower downstream migration with some fish moving in the canal upstream and downstream. From the beginning to halfway down the canal, silver American eel oriented to the north side or were evenly distributed across the canal width. After the halfway point down the canal, their orientation switched to the south side of the canal. This large scale study is a starting point to address mitigation options dealing with turbine mortality but more details are need to better understand eel behavior in the canal and in close proximity to the dam.