The Margaree Salmon Association in northern Cape Breton has been using electrofishing to monitor fish populations in the Margaree River for the past few years. Electrofishing involves briefly stunning fish with an electric current to allow crews to safely capture, measure, and identify them before releasing them back into the water.
According to Michael Fabiano, the conservation co-ordinator of the association, electrofishing operations run from May to late September with a two percent mortality rate among the thousands of fish processed each season. Crews prioritize fish safety, refraining from shocking fish when water temperatures are too high.
To minimize the risk of electric shock, crew members wear heavy rubber gloves and chest waders while setting current levels to temporarily immobilize fish for a few seconds. The crew surveys various locations along the 120-kilometre river to pinpoint the most productive streams and evaluate the overall health of the fish population, primarily consisting of trout and Atlantic salmon, with occasional eels and lampreys.
This season, the association has caught and released approximately 1,800 fish across nine streams, a decrease from the previous year. This decline is likely attributed to the challenging conditions experienced in the previous year, characterized by low water levels and high temperatures due to a severe drought impacting the Margaree River.
Paul MacNeil, the association’s president, highlighted the increased focus on scientific research due to reduced data collection efforts by Fisheries and Oceans Canada over the past five years. The association collaborated with the Chéticamp River Salmon Association to acquire electrofishing equipment, enabling more accurate assessment of juvenile fish populations compared to traditional fish-counting methods.
Electrofishing allows for comprehensive data collection on juvenile fish within specific areas, providing valuable insights into the river’s health, especially as environmental conditions evolve.