“No magic solution” to combat cyanobacteria

From the top of his pontoon, Bertrand Gagnon points out the troubled waters that line his land. Meanwhile, To its great despair, Lake Tomcod, like many bodies of water in Estrie, is colonized by algae and by cyanobacteria.

For the past ten years. Similarly, the association of residents, of which he is the president, has multiplied initiatives to try to slow down their progress. However, In vain.

When I arrived. However, 19 years ago, the lake was already a little affected by cyanobacteria, but over the years, the situation has worsenedsays the treasurer of the association of Lake Tomcod, Josée Picard.

Wastewater treatment. Additionally, However, construction of construction waste, riparian bands, reduction of agricultural pollution, most of the known solutions have been applied around the small lake which is surrounded by sixty residences.

The association even obtained ultrasound devices that emit fatal frequencies for cyanobacteria, also called blue-green algae. Moreover, Four machines were installed in 2017 in strategic locations on the water.

This method makes it possible to punctually reduce the efflorescences of cyanobacteria. Consequently, except that this is insufficient, because “no magic solution” combat cyanobacteria the lake has accumulated significant reserves of nitrogen, nitrates, potassium and, above all, phosphorus.

This mass of nutrients generally comes from industries, wastewater and fertilizers spread over agricultural land. Nevertheless, Cyanobacteria love it and here they are well served. Moreover, The lake had a 30 -foot depth [plus de 9 mètres]now. Nevertheless, it’s more than 12 or 13 feet [environ 4 mètres] Because it has filledexplains Josée Picard.

As soon as there is wind or hot weather, the waters of the lake are disturbed and cyanobacteria are multiplying.

"no magic solution" combat cyanobacteria – "no magic solution" combat cyanobacteria

Bacteria called in reinforcement – "no magic solution" combat cyanobacteria

To remedy this. Meanwhile, there is the option of emptying the lake and mechanically clearing the nutrients. For example, A large deployment operation which turns out to be expensive.

The association of Lake Tomcod would rather make a biological treatment. For example, To his great despair, this type of intervention is slow to be approved.

The president of the Nuvac firm, Bruno Demers, is regularly contacted by desperate residents. However, His company markets products based on bacteria and enzymes, including a preparation for lakes.

There is nothing chemical. “no magic solution” combat cyanobacteria this mixture of bacteria digests organic matter and is absolutely nothing harmful for water bodies and for fishassure M. Demers.

The treatment is sold in the form of a powder which can be poured directly into the rivers. Nuvac has already experienced its treatment at Lake Drolet. Estrie, in 2018, under the supervision of the Quebec government and McGill University.

At the time. the lake was not very pretty, there were a lot of cyanobacteria. Today, he is in perfect health.

By seeing the encouraging results at Lake Drolet, the Lake Tomcod association would like to finance part of the operations with the support of the federal and provincial governments. The bill would amount to almost $ 50,000 in the first year, then “no magic solution” combat cyanobacteria ten thousand the following years.

At one point. we must take action, we know that it worksget impatient by President Bertrand Gagnon, while ensuring that its members would be ready to pay from their pocket so that their lake will find its superb.

Local elected officials were asked to try to advance the file. The federal deputy Éric Lefebvre. of the Conservative Party, and his provincial counterpart, André Bachand, of the Coalition Avenir Québec, were listening, but did not follow up.

"no magic solution" combat cyanobacteria – "no magic solution" combat cyanobacteria

Complex and endless approaches

The Nuvac firm launched an approval process in 2022 from the federal government. Complex and endless approaches, according to Bruno Demers, who is about to take the last step. He plans to deposit the large file in the fall and he will then have to wait up to 16 months … if all is well.

Is there a way to do faster than that? Because our lakes need to be corrected quicklyhe lets go, annoyed.

The length of the procedures does not surprise Sébastien Faucher. professor of microbiology at McGill University, among others because the effectiveness of “no magic solution” combat cyanobacteria treatments is difficult to prove in a natural environment. He suspects the authorities to redouble their prudence.

In many cases. the volumes of water are immense and the proliferation factors of cyanobacteria are multiple: variation in temperatures, precipitation, influencing influenza, improvement in wastewater management, etc.

It is difficult to separate the variables that can influence the amount of efflorescences. therefore measure the impact of productshe says.

According to him. the other obstacle remains the cost linked to the recurrence of treatments, which should be continued over several years without knowing if they are really effective. A major challenge, especially for small municipalities if they do not obtain government financial support.

I am not sure that treating a 10 km2 lake with products is a solution. just because the amount of “no magic solution” combat cyanobacteria products would be enormous.

The microbiologist notes, however, that this strategy could be beneficial in small bodies of water, as in Lake Tomcod, especially if there is no nuisance on the environments, while specifying that this last point is not always easy to demonstrate in the long term.

"no magic solution" combat cyanobacteria – "no magic solution" combat cyanobacteria

Reduce nutrient intake

No question. however, to give up, according to Sébastien Faucher, who regularly intervenes with lakes associations to promote participatory citizen science.

It is convinced that it is necessary to apply different methods and, in particular, reduce the supply of nutrients. Putting is sometimes delicate, because they can conflict with economic or recreational activities.

For example, riparian bands can encroach on agricultural land. His studies have also shown that it is beneficial not to mix sediment too much. therefore prohibit certain boat trips.

People stay around a lake because they want to make the boat, there is no easy solutionunderlines Mr. Faucher.

I don’t “no magic solution” combat cyanobacteria think there is a short -term magic solution for cyanobacteria. in Quebec.

One of the main solutions is outside the lakes, since a national research has just proved that the proliferation of cyanobacteria is largely caused by global warming.

This study published in late July in Nature (new window)codirigated by McGill University. Laval University, also demonstrates that algae are growing throughout the country with the dangers associated with their proliferation. Cyanobacteria can cause vomiting, headache or irritation. They also represent a threat to animal health.

The citizens left to their own devices

Almost everywhere in Quebec. residents’ associations feel abandoned by governments, in particular by Quebec. While the problems related to algae is increasing. the Quebec Ministry of the Environment has just slashed in the budget of the Voluntary Lakes (RSVL) surveillance network.

The RSVL Offers citizens, notably by distributing subsidies to carry out laboratory analyzes. Because of the compressions, surveillance decreases: in 2025, less than 400 lakes will be sampled, “no magic solution” combat cyanobacteria compared to 537 last year.

In 2018. the ministry had already decided to no longer send an inspector to follow the development of cyanobacteria in contaminated lakes. Only extreme cases are examined when citizens ring the alarm.

Since we do not know the extent of the problem, how can we plan actions to attack us? wonders the biologist Henri Fournier, vice-president of the Quebec Federation for the Defense of Lakes and Rivers. He accuses the government of negligence in the scientific monitoring of the health of the lakes.

The RSVLit’s really a beautiful program. we were starting to have great data and it’s important to have them in the long termadds Professor Yannick Huot, from the University of Sherbrooke.

The RSVL Watches nearly 900 lakes thanks to the contribution of residents. A real tour de force, according to Mr. Huot, because an investigation of such a scale is almost impossible for academics. Quebec has half a million lakes, which makes an exhaustive observation impossible.

A prioritization exercise has been carried out in order to maintain. ensure coherent follow -up with the objectives of RSVLassures Robert Maranda, of the Ministry of the Environment, the Fight against Climate Change, Wildlife and Parks, in an email on Radio-Canada.

The president of the Environment Committee of Lake Roxton. Simon Turcotte, has the feeling that the pressure is always more on the shoulders of citizens and municipalities. He expects “no magic solution” combat cyanobacteria from the government more collaboration . above all a plan d’action Detailed and ambitious for preserving the health of lakes.