A Quebec scuba diver recently swam the entire length of the Island of Montreal to highlight pollution in the St. Lawrence River.

Nathalie Lasselin came up with the idea for the 70-kilometre journey after undertaking adventurous dives all around the world.

“I explored the Arctic, I explored caves in remote China, all those places, and I’m like, ‘What’s it like down there?’” she said of the river that supplies many Quebecers’ drinking water.

As part of the project, Lasselin pulled 300 kilograms of junk out of a small stretch of the river and analyzed samples from the river that revealed pesticides and drugs.

Then, last week, she attempted do the entire swim all at once without resurfacing.

It turned out to be a beautiful day, which drew out pleasure crafts that pushed her closer to shore. Overgrown weeds ended up jamming her propeller, forcing Lasselin to resurface about halfway through the dive.

But she pushed on and completed the mission in a little over 30 hours.

Lasselin said she hopes the exhausting feat inspires people to change how they treat the river.

“We talk a lot about politicians not doing enough about the environment and actually, I think the only people who can really do something is us, as individual citizens,” she said. “We can’t wait anymore.”

With a report from CTV’s Genevieve Beauchemain in Montreal