FISHING WITH ELECTRICITY
It’s harmless — and it reveals there are 72 species swimming in Toronto’s waters,
Many Torontonians don’t believe there are dozens of varieties of fish living in the city’s harbour. A night of electrofishing, however, would shock even the biggest skeptics. Everything from bowfin to northern pike — 72 species in all — lurks in the waterfront’s murky depths
Electrofishing is exactly what it sounds like. Technicians from the Toronto and Region Conservation Authority (TRCA) use electricity to temporarily stun fish, causing them to float to the surface so they can be counted, measured and, sometimes, tagged. At the bow of a metal-based boat, two long-armed anodes reach into the water, sending out a seven-amp electrical current. The electricity has a range of about two metres; the natural reaction of the fish is to be drawn to the electrical field.
“It contracts their muscles and they go nose-first towards the source of the electricity,” explains technician Brian Graham about the impact of the current on the fish. “Their muscles get so tight they can’t move, but since fish have a swim bladder, they float. They come right up to the surface where we can net them. Put them in the (lab’s) well, do our weights and measurements, and put them right back in the water.” Graham says the process does the fish “no harm at all.” The electricity also doesn’t damage a female’s eggs.
Starting in late afternoon and working deep into the night, the boat will visit several sampling locations, moving slowly through the water as the crew nets the temporarily paralyzed fish. They visit sites where they have previously taken samples in order to track populations over years. “If we’re seeing more fish, better diversity, better quality of fish then things are improving,” says Graham. Electrofishing has taken place on the lake since the ’80s.
The crew tests areas before, during and after the TRCA has altered fish habitats, to ensure the changes are working. The TRCA does nighttime electrofishing over two weeks in the spring and fall, but they carry out daytime collections whenever there is no ice on the water. They often work in darkness, and citizens on shore have sometimes suspected them of poaching or smuggling. It is illegal for anyone other than the trained TRCA technicians to use electricity to catch fish.
Graham has been electrofishing on the lake since 2007 and says Toronto’s waters have improved dramatically. “We used to see a lot more of what we call coarse fish: white suckers, carps, things like that; fish that are more tolerant. You don’t have to have great habitat for them to exist. Now we’re seeing a lot more of the pike, the salmon and the bass and all sorts of other less coarse fish showing up. It used to be you’d go on a run and catch three or four different species. Now we’re catching 10.”
The electrofishing boat and its floating aqua lab, where the fish are measured, visited eight locations on a warm night in October. Just over eight minutes of fishing along the walled, cement shore at York Quay boat slip, a little west of the ferry docks, yielded 88 fish representing eight species.
Fishing for almost 17 minutes — the TRCA’s comparative standard of 1,000 seconds of collecting — at Long Pond in the middle of the Toronto Islands yielded 94 fish from 11 species. The presence of pike is a good indicator of a lake’s health. “The pike is the top order of predator,” says Graham. “You need to have that good food base, good forage base, for him to survive.”
Fish captured at other stops this night included bowfin, rainbow trout and Chinook salmon. “People think there are one or two species of fish in Lake Ontario,” says Graham. “Then you take them out in a boat, show them what’s in here, and it kind of blows their minds.” The crew previously once caught a tiger muskie, which was unexpected because typically there are no muskies in the lake near Toronto.
Among the bigger success stories from the water and habitat improvement is the resurgence of the American eel. The TRCA used to catch “maybe” one a year, usually around the Toronto Islands. “Now we’re catching them all across the waterfront.” Adds Graham, “We’re seeing a lot more smallmouth bass than we used to,” largely, he believes, because of habitat improvements, particularly to the east around the Port Union area.
Graham says that Lake Ontario remains a “kind of a big secret” when it comes to recreational fishing. “Everyone thinks that if they want to go fishing, they have to jump in a car and go three hours north, and that’s entirely untrue. They can jump on a streetcar or walk out of their condo and fish right on the lake. There’s all sorts of good stuff down there.”