"If it continues like this, the campsite will close": cyanobacteria, the poison of summer in this corner of the Dordogne

Swimming is prohibited on several beaches along the banks of the Dronne, in the Périgord Vert region. While some bathers continue to take a dip despite the risks, this situation is not without economic consequences, particularly in Lisle and Tocane-Saint-Apre (24), which have been affected since mid-July.

T he thermometer is flirting with 40 degrees on Tuesday, August 12, in Tocane-Saint-Apre, about twenty kilometers west of Périgueux. Yet, on the banks of the Dronne, the public beach is sparse. In the shade of the trees, the members of the Quintet family are enjoying this cocktail of coolness and calm. "We've been here for two weeks, and there aren't many people," notes Christopher, the son. "Usually, we have trouble finding a spot."

And for good reason, swimming has been prohibited in this area since Friday, July 11 (1). The reason is the presence of cyanobacteria – microorganisms that thrive in fresh water and can release toxins – detected in excessive numbers during analyses by the Nouvelle-Aquitaine Regional Health Agency (ARS). They can cause various symptoms in humans (and also in animals) : stomach aches, headaches, and even severe neurological or liver damage, diarrhea, vomiting, irritation of the skin, eyes, throat, etc.

A risk that some vacationers don't hesitate to brave, despite the presence of information signs. Maya, a Parisian student, on vacation with her grandparents, also arrives at the water's edge, determined to cool off despite everything. "I come swimming every summer," explains the young woman. It's ultimately at the sight of microorganisms that she decides not to get in the water.

As for the Quintet—Christopher, his father Joël, his stepmother Gabrielle, his partner Georgia, and the nine children they care for—they don't hesitate. "We learned there were cyanobacteria when we arrived, but that didn't stop us," assures Joël. The Brest family comes to the Dordogne every summer. "At first, I was scared; we didn't let the little ones swim," explains Georgia. "But we saw that people were going in the water, so we do the same. We shower after swimming, and we haven't gotten sick."

The presence of cyanobacteria is, however, truly poisoning the season at the affected campsites. Jonathan Jobin, manager of the Tocane campsite, is dismayed: "There aren't many people, we have shortened stays and vacationers who leave when they learn that swimming is closed. Attendance is 20 to 30% lower than in other years." The canoes he rents are also staying at the dock.

"This is the first time I've seen a swimming ban here."

In the neighboring town of Lisle, the paths of the Pont campsite are also quite empty. At the snack bar, there are no vacationers eating ice cream or drinking soda, but a very worried manager. "Look, it speaks for itself, there's no one there," says Agnès Duclaud. "Usually, it's full between July 15 and August 15."

That day, only about ten of the 47 available spots were occupied. Here too, swimming has been prohibited on the developed beach on the opposite bank of the Dronne since July 11. "People are leaving," the manager continues. "It's too hot to walk around, and they can't swim."

"I'm demoralized. If things continue like this for the next few years, the campsite will close," worries Agnès Duclaud. The village native continues: "This is the first time I've seen a swimming ban here."

On Lisle Beach, Mathieu Monmarson watches over a desert. Hired by the municipality as a lifeguard, the young man hasn't experienced a single day of swimming since the start of his contract. "There's no one there. Normally, there are 150 to 200 people on the beach," he explains.

His salary represents a loss of income. "We signed a contract that we can't break," says Mayor Joël Constant. Fewer bathers also mean fewer tourists for this town of fewer than 900 inhabitants. More than 6,000 people pass through Lisle during the season, "in normal times," according to the mayor.

(1) The ARS only monitors sites listed by town halls, urban areas or the Department. Thus, on August 12, in Grand-Brassac, 5 kilometers from Lisle, around fifty people were cooling off in the Dronne, without a ban.