in Puy-de-Dôme, scientists succeed in limiting the scourge of cyanobacteria that proliferate in summer

In a bathing suit on the beach, Isidore is ready. His mother promised him this afternoon to take a dip in the lake at the resort of Super-Besse (Puy-de-Dôme). “I was planning to swim but in the end we are not allowedregrets the little boy, because there are bacteria in the lake.” His mother had noticed the nets laid, and the display. “The beach is closed, but we still enjoy the sand”she assures.

The lake has been closed for three weeks because of cyanobacteria, nicknamed “blue algae”. With the strong heat of July, they proliferated in the lake. But it’s not algae: it’s bacteria that produce toxins that are dangerous to humans and animals.

“There, we put beautiful blue nets so people can no longer pass too muchexplains one of the lifeguards, almost idle. Then there are the dogs. Last week, it was super hot, the dogs came, drank water, so we did a lot of prevention in relation to that, so that they didn’t get sick.” Ingested in large quantities, cyanobacteria can cause death, especially in pets.

However, a few kilometers away, Lake Aydat is spared: there are no restrictions, in particular thanks to the redevelopment of a wetland. “You should know that before, there were football fields hereexplains Erwan Roussel, research engineer at Clermont Auvergne University. Since 2012, the intermunicipalities have implemented this work and restored the wetland and restored its self-purifying functions.

Today, this wetland is made up of basins, streams that meander through vegetation that is reclaiming its rights. “When we look, we are in the heart of the wetlandexplains Erwan Roussel. We really see a luxuriance of really diversified plants, with several shrub layers, a landscape mosaic. The birds are back on this wetland.”

“These are ecosystems that are super beneficial for hosting many animal and plant species.”

Erwan Roussel, research engineer at Clermont Auvergne University

at franceinfo

Something to amaze walkers. But this zone plays above all a role of filter by trapping the phosphorus resulting from the breedings. “And this landscape mosaic there, it finally comes to drain and filter the water by removing the overloaded nutrientscontinues the engineer. And finally, at the exit of this wetland, we find a little more filtered water, a little cleaner, which flows into the lake.

Moreover, Lake Aydat has not experienced a cyanobacteria alert for four years.