The Lachine Canal stank for most of the 1970s. Not metaphorically. You could smell it from a block away. Raw sewage, industrial waste, oil from a thousand leaky boat engines. People fished there anyway. They didn't eat what they caught. Nobody was that desperate.
Now you can see the bottom in spots. Sturgeon are back. So are pike. The city spent a billion dollars on sewage tunnels and treatment plants. It worked. Montreal's water is the cleanest it's been since the 1920s.
Don't drink it. Don't get complacent.
The Runoff Problem Nobody Solved
Every time it rains, the St. Lawrence and the Lachine and the Rivière des Prairies take a hit. Not from factories anymore. Those pipes are monitored. The problem is streets and parking lots and highways. Rain hits asphalt, picks up tire dust and brake pad residue and leaked oil and road salt and lawn fertilizer and dog waste, then flushes straight into the nearest storm drain. Most of Montreal's storm drains flow to the river without treatment.
That tire dust contains 6PPD-quinone. It's a chemical that comes from car tires breaking down. It kills coho salmon in hours at concentrations measured in parts per billion. Scientists are still figuring out what it does to walleye and perch. Early results aren't good.
The road salt you throw down in February melts ice and runs into the river in March. Freshwater fish don't handle high chloride well. Their gills burn. Their eggs don't hatch. The Rivière des Prairies hits chloride levels in spring that would kill most aquarium fish outright. Native species are tougher, but toughness has limits.
Microplastics Are Everywhere
You've heard this before. It's worse than you think. Researchers dragged nets through the Lachine Canal in 2022 and found microplastic fibers in every single sample. Not most samples. Every one. The highest counts came from spots near laundry outflow. Those fleece jackets you wash? They shed plastic. The water treatment plant catches most of it, but not all. The stuff that gets through ends up in fish guts.
Here's what that means for you as an angler. You catch a nice walleye near the Victoria Bridge. You fillet it. You eat it. You just ate the same microplastics that fish ate. Nobody knows what that does to a human body long term. The research is ten years behind the problem.
"Montreal's water is dramatically better than it was. That's real progress. But better doesn't mean clean. It means less disgusting. The chemical threats have shifted from obvious poisons to slow, invisible ones."
What You Can Actually Do
Stop using fertilizer within thirty meters of any waterway. That includes the canal towpath and the river shoreline. Phosphorus from lawn food feeds algae blooms. Algae blooms die and rot. Rotting algae sucks oxygen out of the water. Fish suffocate. Your perfect green lawn isn't worth dead walleye.
Wash your car at a commercial car wash. They recycle water and send the dirty stuff to treatment. Washing on your driveway sends soap and tire grime and brake dust straight to the storm drain.
Pick up your dog's waste. Bag it. Trash it. Rain hits dog waste and bacteria levels spike. The beach at Verdun closes every summer because of bacteria. That bacteria comes from pets and geese and faulty septic systems. You can't control the geese. You can control your dog.
Tell the city when you see something wrong. The 311 app takes two minutes. Report illegal dumping. Report weird discoloration. Report a dead fish float. The city doesn't have enough inspectors. You are their eyes.
The Honest Take
Montreal's water is dramatically better than it was. That's real progress. But better doesn't mean clean. It means less disgusting. The chemical threats have shifted from obvious poisons to slow, invisible ones. You can't see 6PPD-quinone. You can't smell microplastics. The fish look healthy. They fight hard. They taste fine.
That's the trap. Things look okay, so you assume they are okay. They're not. They're just better than they used to be.
Fish the canals. Fish the river. Enjoy the comeback. Just know what's still out there. Cut open a walleye's stomach sometime. You'll find line fragments and plastic fibers and the occasional cigarette filter. That's the real water quality report. Nobody prints it on a nice brochure.
20+ years fishing Quebec's freshwater systems. Kayak angler, catch-and-release advocate, and founder of Sub Urban Anglers.
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