Although a few cottages on stilts can be found in Baie-du-Febvre, no one builds their house at the water’s edge. In the area surrounding Lake Saint-Pierre in Québec, nearly every spring brings a flood so intense it doubles the surface area of the lake.

For a period of nearly two months, many fish use the flooded fields to reproduce. Yellow perch is one such species: in mid-April, they cross the treeline, swim a few kilometres, then wrap their strings of eggs around submerged vegetation.

This species is part of a completely unique ecosystem — one that enriches human communities as well. Farmers cultivate rich, life-supporting soil; sport and commercial fisherfolk and hunters feed themselves; vacationers wander through picture-postcard landscapes which host a flourishing tourism industry. What’s more, yellow perch are intimately linked to the Abenaki peoples’ way of life.

But the yellow perch population dropped by 79 per cent between 1979 and 2019, while everywhere else in the province, stocks are doing very well. In other words: the yellow perch in Lake Saint-Pierre are in trouble.

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One of the main reasons the shoreline of Lake Saint-Pierre is so exceptional is because of its freshwater flood plain — the largest of its kind in Québec. In addition to a refuge for fish to reproduce, it provides a generous food supply for the fish larvae, which emerge hungry for small invertebrates. The warm, shallow waters of this 32 km long lake contribute to the efflorescence of ample aquatic meadows that are home to an entire ecosystem. In total, 288 species of birds, 79 species of fish, and 24 species of amphibians and reptiles, many of them endangered or vulnerable, frequent this area halfway between Montréal and Québec City. (Not to mention 85,000 human residents, enormous cargo vessels, and several factories.)

This remarkable archipelago — including about a hundred small islands — is a jewel of our environmental heritage. Since 2000 it has been classified as a World Biosphere Reserve by UNESCO; it has also been designated as a “Ramsar site,” a wetland of international importance. This title makes the lake a subject of particular interest, explains Henri-Paul Normandin, spokesperson for the biosphere and former Canadian ambassador. “It’s a little treasure that attracts international attention. We plan to use this to raise awareness and to mobilize the local community as well as other levels of government. Because global issues around biodiversity are also local issues. And what we’re doing—or not doing—on the local scale has an impact on the entire planet.”

Lake Saint-Pierre also acts as a purifying station for the waters of the St. Lawrence. For example, when Montréal dumped large amounts of sewage into the river, it was filtered by the web of marshes. It’s been proven that the water comes out cleaner near Trois-Rivières than it was at Sorel-Tracy.

Toward a more sustainable agriculture

Fisherfolk and farmers have been passing the buck for a long time about the deteriorating health of the yellow perch. “[In the late 1980s and early 1990s], yellow perch fishing was still continuing aggressively, even though their numbers were already in decline,” says Philippe Brodeur, standing in brilliant sunlight. “The landed volume surpassed 300 tons annually in the lake.” At the time, the habitats were able to support this frenetic pace, but low reproduction rates soon made the fishery unsustainable. And in spite of the 2012 moratorium on sport and commercial fishing (which has been extended until 2022), the health of this bioindicator species has remained fragile.

It became clear that the intensive farming of corn and soy in the flood plains — rather than the traditional cultivation of mainly hay and pasture land — had a lot to do with it. The autumn harvest leaves the ground bare, and the yellow perch have nothing to attach their eggs to. When the snow melts, sediments and pesticides stream out all the way to the shores, causing turbidity in the water.

The situation is worrisome enough that a panoply of defenders are showing up to protect Lake Saint-Pierre. Several million dollars have been invested in restoring habitats on the flood plain, as well as upstream from the shoreline. One of the goals is to put sustainable agricultural practices in place.

To plant a prairie

Anne Vanasse is a professor in the Faculty of Agriculture and Food Sciences at University Laval, and co-head of the multidisciplinary pole of expertise for sustainable management of the Lake Saint-Pierre shoreline. For the past three years, she and her team have been collaborating with farmers to test various sustainable agriculture initiatives. Claude Lefebvre, a dairy farmer and mayor of Baie-du-Febvre, is one such farmer. “It’s always the farmers’ fault!” he shrugs, with kind eyes. “But yes, we are aware that we are part of the problem.”

On the land where he grew up in the 1950s, Lefebvre is now trying to establish a meadow of reed canary grass — a perennial plant that’s very resistant to floods because of its extensive root system, making it an ideal refuge for several species. The researchers are banking on this plant (and a few other strategies) to re-establish habitat for the yellow perch. Unfortunately, it’s a fodder that tends to be unattractive to growers; it’s very fibrous, contains little protein, and is not very appetizing for cattle. With his 400-head dairy farm, Lefebvre still sees it as an opportunity worth seizing.

You might think it would be easy to naturalize grassland with plants this hardy, but major floods in 2019 and 2020 delayed seeding, and the farmer worries that the reed canary grass will fail to become established this year because of an exceptionally dry summer. Fortunately, Lefebvre has a quality in common with the planet: resilience.

Other possible solutions are being explored. In monocultured areas, Vanasse and her team are studying intercropping, which consists of sowing, for example, raygrass between rows of corn, and winter wheat or lotus in soy fields. These herbaceous plants may not help the yellow perch habitat directly, but once the harvest is cut, they create a carpet that reduces soil erosion and may help slow sediment runoff into the lake.

Another initiative currently under study consists of establishing permanent, four-metre-wide bands near ditches on arable land, to provide the fish with something to attach their eggs to.

A return to hay

For more than 30 years, Laurent Brissette has owned land near a magnificent string of small islands, in Saint-Ignace-de-Loyola. It’s one of the spots where the lake resembles the Louisiana bayou.

After growing soybeans (“We had to use a lot of herbicides and pesticides for it to be profitable, and I didn’t like that,” says Brissette on the phone), this “gentleman farmer” returned to his roots and began to grow hay, just like the first generations of farmers on the flood plains. Alone, he worked hard to bring back the wildlife, reconnecting bits of stagnant marsh by hand. “I even managed to make a ditch for fish with a pickaxe. It took five hours!” he adds, and his pride resounds all the way to Montréal. For his retirement, he wanted to see this place become a protected area — a dream that was realized with help from the Nature Conservancy of Canada (NCC).

In 2020 this non-profit organization (NPO) took possession of 12 hectares belonging to Brissette. The NCC is one of the organizations that actively contributes to the protection of the yellow perch habitat in Lake Saint-Pierre, acquiring land to preserve it over the long term and to encourage environmentally responsible agriculture. “People think that when we restore the ecological functions [of a place], there’s no room left for humans, but this isn’t true. We do it for the wildlife, but also to promote economic activity that anyone can support — not just to allow a handful of owners of monoculture farms to make a buck,” says the expressive Julien Poisson, program director at the NCC.

Today, Brissette’s land teems with life thanks to the combined efforts of the farmer and the NPO. Ducks and farmland birds nest between the milkweed and tall grass. The NCC has plans to further diversify the plants as well. “For the yellow perch, we already have a 95 per cent gain. Before, they had stopped coming here, and now, it’s a veritable fish nursery!” says Poisson, a biologist by training.

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The state of the yellow perch is still concerning in the Lac Saint-Pierre Biosphere Reserve; the battle is not over. But encouraging improvements are taking place on the local scale.

It always takes time to change people’s minds, but despite a few pockets of resistance, the farming community is decidedly in problem-solving mode now. “The community might not have been ready 10 years ago, but now, it’s ready. I know a few reluctant ones who didn’t want anything to do with a gang of biologists and have now changed their way of thinking. We’re conscious of what’s been lost,” says Claude Lefebvre. “That said, if these lands [on the flood plain] weren’t farmed, we’d have to cultivate elsewhere. Who’ll feed us? Brazil? We’re trying to limit our impact on the environment as much as possible, but can we still farm while improving the lot of the yellow perch? That’s what remains to be seen,” concludes the optimistic farmer.

To learn more about how the people of Québec’s Lac Saint-Pierre region are taking creative steps to restore the lake to its former glory, check out Episode 6 of Striking Balance, a TVO original documentary