(Tadoussac) The cold water takes your breath away as soon as you dive in. Despite wearing a diving suit that feels like a second skin, the 4°C temperature is unmistakable. Anne-Marie Asselin appears to be in her element. Floating on the surface in her bright green suit, with a mask and snorkel, the marine biologist surveys the depths of the St. Lawrence.
Published at 6:00 a.m.
Suddenly, she takes a deep breath and, with a swift kick of her flipper, descends to a depth of about ten meters, aided by the weights at her waist. She scours the bottom for a few moments, stirring up a small cloud of sediment, before resurfacing with a big smile, holding up the two sea urchins she collected.
![](https://i0.wp.com/mobile-img.lpcdn.ca/v2/924x/a59ed2e29aa3337486c9adeac519335b.jpg?w=800&ssl=1)
PHOTO EDOUARD PLANTE-FRÉCHETTE, THE PRESS
Anne-Marie Asselin collected sea urchins.
These small invertebrates will be brought back to the sailboat Vanamo, which accompanies the Blue Expedition, before being sent to a laboratory for analysis of the microplastics they contain.
Mapping plastic pollution
The expedition focuses not only on sea urchins but also on other invertebrates, as well as surface water and riverbed sediments to be collected and analyzed.
The team repeated this process at various locations over 18 days in the Saguenay River and the St. Lawrence Estuary, from La Malbaie to Les Escoumins.
![](https://i0.wp.com/mobile-img.lpcdn.ca/v2/924x/0263b0c9fda238858ba6f244297fb675.jpg?w=800&ssl=1)
PHOTO EDOUARD PLANTE-FRÉCHETTE, THE PRESS
The crew members lived together for more than two weeks.
“This allows us to create an overview of microplastic pollution in the river and to analyze how it has evolved over the years by collecting sediment samples,” explains Miguel Felismino, a biology doctoral student at McGill University.
The team also gathered waste from the banks, which had washed ashore after drifting with currents. They meticulously cataloged it into no fewer than 156 categories to trace its origins.
The objective of the Blue Expedition is to map waste and microplastics while also understanding how they arrived there.
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PHOTO EDOUARD PLANTE-FRÉCHETTE, THE PRESS
Anne-Marie Asselin, marine biologist, founder of the Blue Organization and head of the Blue Expedition, showcasing some of the plastic waste collected during the expedition.
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PHOTO EDOUARD PLANTE-FRÉCHETTE, THE PRESS
Marine biologist highlights the omnipresence of plastic.
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PHOTO EDOUARD PLANTE-FRÉCHETTE, THE PRESS
Plastic bags rank among the most common types of waste discovered.
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PHOTO EDOUARD PLANTE-FRÉCHETTE, THE PRESS
A variety of waste is found, including shoes.
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The pervasive plastic
This expedition marks the second undertaken by the Organisation Bleue, established by Anne-Marie Asselin. The first, in 2022, focused on plastic pollution in the Gulf of St. Lawrence; this year, the team is examining the maritime estuary of the river further upstream.
Read our article on the first Blue Expedition
“What we discovered during these two expeditions is that plastic is truly everywhere, no matter where we go,” Anne-Marie Asselin remarks with a sigh. “There is no place that is free from it. It is present in the air, in the water, and on land. It’s omnipresent.”
![](https://i0.wp.com/mobile-img.lpcdn.ca/v2/924x/7b19437703f53baf83bae0ef9f1b5977.jpg?w=800&ssl=1)
PHOTO EDOUARD PLANTE-FRÉCHETTE, THE PRESS
The sunset over the Saint Lawrence.
“Contrary to what one might think, the closer you approach the Gulf, the greater the density of plastic. While people often believe that areas around major urban centers, such as Montreal, Quebec City, or Trois-Rivières, are the most polluted,” explains Laurence Martel, project coordinator at Organisation Bleue. “This clearly illustrates the impact of marine currents within the river,” adds the geographer specializing in hydrology.
Cigarette butts were by far the most commonly found waste, followed by plastic bottles and bags, then single-use utensils.
Regarding microplastics, the main items detected are synthetic microfibers shed from clothing during washing.
Interestingly, the expedition found the largest accumulations of waste on small, wild islands, distant from any human activity, where refuse had collected for years.
Enhanced understanding for better prevention
In 2019, the Blue Organization initiated a public database to identify plastic waste contaminating waterways and oceans in Eastern Canada, with numerous organizations contributing regularly. Another database assessing the presence of microplastics is also expected to be launched soon.
Ultimately, this research could motivate policymakers to implement actions against this issue.
![](https://i0.wp.com/mobile-img.lpcdn.ca/v2/924x/fe3699652ffb3da89377475d1f9e4729.jpg?w=800&ssl=1)
PHOTO EDOUARD PLANTE-FRÉCHETTE, THE PRESS
Anne-Marie Asselin, marine biologist and founder of the Blue Organization
The federal government aims to protect 30% of the oceans by 2030, yet much of the plastic polluting them originates from rivers and streams. This research is expected to help inform more effective decision-making.
Anne-Marie Asselin, marine biologist and founder of the Blue Organization
All levels of government, including municipal, could take advantage of this information.
Scientists noted a noticeable difference in the nature of some of the waste found between the two expeditions: from 2022 to 2024, for instance, plastic utensils were replaced by wooden ones. This shift is attributed to Montreal’s ban on single-use plastics implemented in March 2023.
“While this waste still ends up in the St. Lawrence, at least wooden utensils take one or two years to decompose compared to hundreds of years for plastic,” Laurence Martel states. “This demonstrates that it is possible to mitigate plastic pollution.”
“Microplastic pollution in the St. Lawrence is comparable to that of the most polluted rivers globally. We must question the extent of Canada’s contribution to the Great Pacific Garbage Patch,” notes Anne-Marie Asselin. “Immediate action is essential to implement preventive measures to reduce our waste at every level.”
Read our profile of Anne-Marie Asselin
The icy water takes your breath away as soon as you enter. Despite the diving suit, which feels like a second skin, its 4°C temperature is clearly felt. Anne-Marie Asselin seems in her element. Floating on the surface in her apple green suit, equipped with a mask and snorkel, the marine biologist scans the depths of the St. Lawrence.
Published at 6:00 a.m.
![Share](https://i0.wp.com/static.lpcdn.ca/lpweb/mobile/img/share-icon.png?resize=16%2C18&ssl=1)
Suddenly, she takes a deep breath and, with a stroke of her flipper, dives to a depth of about ten meters, helped by the weights she wears at her waist. She rummages for a few moments at the bottom of the water, stirring up a small cloud of mud, then comes back to the surface and brandishes, all smiles, the two sea urchins she has recovered.
![Anne-Marie Asselin collects sea urchins](https://i0.wp.com/mobile-img.lpcdn.ca/v2/924x/a59ed2e29aa3337486c9adeac519335b.jpg?w=800&ssl=1)
PHOTO EDOUARD PLANTE-FRÉCHETTE, THE PRESS
Anne-Marie Asselin collected sea urchins.
These small invertebrates will then be brought back onto the sailboat Vanamo, which accompanies the Blue Expedition, before being sent to a laboratory to measure the quantity of microplastics they contain.
Mapping plastic pollution
The expedition is not only interested in sea urchins, far from it. Other invertebrates, but also surface water and sediments at the bottom of the river, will also be collected and analyzed.
The team repeated the operation in different locations, for 18 days, in the Saguenay River and the St. Lawrence Estuary, between La Malbaie and Les Escoumins.
![The crew members lived together for more than two weeks](https://i0.wp.com/mobile-img.lpcdn.ca/v2/924x/0263b0c9fda238858ba6f244297fb675.jpg?w=800&ssl=1)
PHOTO EDOUARD PLANTE-FRÉCHETTE, THE PRESS
The crew members lived together for more than two weeks.
“This allows us to draw up a portrait of the microplastic pollution of the river, and to go back a few years by collecting sediments, to see how it has evolved over time,” explains Miguel Felismino, a doctoral student in biology at McGill University.
The team also collected waste from the banks, which had washed up there after drifting with the currents. They carefully listed and classified it into no fewer than 156 categories, in an attempt to trace its origin.
Because the goal of the Blue Expedition is to map waste and microplastics, but also to understand how they got there.
-
PHOTO EDOUARD PLANTE-FRÉCHETTE, THE PRESS
Anne-Marie Asselin exhibiting some of the plastic waste collected during the expedition.
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PHOTO EDOUARD PLANTE-FRÉCHETTE, THE PRESS
Marine biologist notes omnipresence of plastic.
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PHOTO EDOUARD PLANTE-FRÉCHETTE, THE PRESS
Plastic bags are among the most common types of waste found.
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PHOTO EDOUARD PLANTE-FRÉCHETTE, THE PRESS
But we find all kinds of waste, like shoes.
1/4
The ubiquitous plastic
This expedition is the second carried out by the Organisation Bleue, an organization founded by Anne-Marie Asselin. The first, in 2022, focused on plastic pollution in the Gulf of St. Lawrence; this year, the team is focusing instead on the maritime estuary of the river, a little further upstream.
Read our text on the first Blue Expedition
“What we found during these two expeditions is that plastic is truly omnipresent, wherever we go,” says Anne-Marie Asselin with a sigh. “There is no place that is free of it. In the air, in the water, on the ground. It’s everywhere.”
![The sun sets over St. Lawrence](https://i0.wp.com/mobile-img.lpcdn.ca/v2/924x/7b19437703f53baf83bae0ef9f1b5977.jpg?w=800&ssl=1)
PHOTO EDOUARD PLANTE-FRÉCHETTE, THE PRESS
The sun sets over the Saint Lawrence.
“And contrary to what one might think, the closer you go to the Gulf, the more the density of plastic increases,” explains Laurence Martel, project coordinator at Organisation Bleue. “While in the collective imagination, we tend to think that the areas around large urban centres are the most polluted – like near Montreal, Quebec City or Trois-Rivières. This clearly demonstrates the impact of marine currents in the river,” adds the woman who is also a geographer specializing in hydrology.
The waste they found in greatest number were, by far, cigarette butts, followed by plastic bottles and bags, then single-use utensils.
As for microplastics, what we mainly find are synthetic microfibers from washing clothes.
And it was on small wild islands, far from any human presence, that the expedition discovered the largest dumps: the waste that had drifted there had accumulated there for years.
Better understanding for better prevention
A public database was launched in 2019 by the Blue Organization to identify plastic waste polluting waterways and oceans in Eastern Canada. Many organizations contribute to it regularly. Another database, which will this time assess the presence of microplastics, should also soon see the light of day.
Ultimately, this research could prompt policymakers to take action to stem the problem.
![Anne-Marie Asselin, founder of the Blue Organization](https://i0.wp.com/mobile-img.lpcdn.ca/v2/924x/fe3699652ffb3da89377475d1f9e4729.jpg?w=800&ssl=1)
PHOTO EDOUARD PLANTE-FRÉCHETTE, THE PRESS
Anne-Marie Asselin, marine biologist and founder of the Blue Organization.
The federal government wants to protect 30% of the oceans by 2030, but much of the plastic that pollutes them comes from rivers and streams. It is hoped that this research will allow it to make more informed decisions.
Anne-Marie Asselin, marine biologist and founder of the Blue Organization
All levels of government could benefit, including municipal.
The scientists explain that they noticed a clear difference between the two expeditions in the nature of some of the waste found: between 2022 and 2024, for example, plastic utensils gave way to wooden ones. A difference that they attribute to the ban on single-use plastic in Montreal, in March 2023.
“This waste continues to end up in the St. Lawrence, but at least the wooden utensils will take one or two years to decompose, rather than hundreds of years,” says Laurence Martel. “This shows that it is possible to slow down plastic pollution.”
“The pollution of the St. Lawrence by microplastics is comparable to the most polluted rivers in the world. We can also wonder to what extent Canada contributes to the continent of plastic in the Pacific Ocean,” says Anne-Marie Asselin. “It is urgent to put in place prevention policies to avoid releasing so much, and at all levels.”