The Margaree Salmon Association in North Cape Breton has been utilizing electrofishing as a method to monitor fish populations in the Margaree River for the past few years. This technique involves using an electric current to momentarily stun fish, allowing the crews to safely capture, measure, and identify them before releasing them back into the water.
Michael Fabiano, the conservation co-ordinator at the association, mentioned that electrofishing operations run from May to late September each year. Despite processing thousands of fish in a season, there is only a two per cent mortality rate. Safety of the fish is the top priority, with precautions taken such as avoiding electrofishing in high water temperatures.
The crew carefully controls the electric current levels to ensure that the fish are only momentarily affected, with crew members wearing protective gear like heavy rubber gloves and chest waders to prevent any injuries. In the 18 months Fabiano has been with the group, no crew members have experienced serious electric shocks.
The survey teams cover various locations along the 120-kilometre river to pinpoint the most productive streams and evaluate the overall health of the fish population. The catch mainly consists of trout and Atlantic salmon, with occasional eels and lampreys making up about 95 per cent of the catch.
This season, the association has captured and released approximately 1,800 fish across nine streams, showing a decrease from the previous year. Fabiano attributes this decline to the challenging conditions experienced the year before, including low water levels and high temperatures due to a severe drought that impacted the Margaree River.
Paul MacNeil, the association’s president, mentioned that they intensified their scientific research efforts due to reduced data collection by Fisheries and Oceans Canada over the past five years. Established in 1982, the group sought reliable data to monitor river health amidst changing climate patterns.
To compensate for the lack of data collection, the association partnered with the Chéticamp River Salmon Association to acquire electrofishing equipment. While traditional fish counting methods involve swimming in the river, MacNeil highlighted that electrofishing provides more accurate data on juvenile fish populations.
For more accurate juvenile population data, electrofishing captures all juvenile fish in a specific area, providing a comprehensive understanding of the fish population in that territory, MacNeil added.
