They have been around for years. Every year, from spring to summer, green algae pollute the Breton coast, especially Côtes d’Armor (22) and Finistère (29). How are they formed? Are they really dangerous?
For almost 40 years, these living organisms capable of photosynthesis – better known as green algae – have been found on the French coast from Normandy to the south of Brittany.
Very invasive, they decompose in 48 hours, become particularly fragrant and are considered toxic because they produce gases resulting from their putrefaction. It is a scourge for the inhabitants and the mayors of these French municipalities, affected each year by the phenomenon between the months of May and September, in the middle of the tourist period.
But it is above all a real question of public health, whereas since the end of the 1980s, at least 40 animals and 3 men have died on the beaches of Brittany, in conditions which still remain more or less uncertain today.
back in time
In the comic magazine “Green Algae: The Forbidden History” published by Delcourt, journalist Inès Léraud traces the history of the proliferation of these green algae, from their appearance until today, beginning her story with the one of the very first people to have “sent the alarm”: Pierre-Philippe, an emergency doctor who became concerned after the death of a 26-year-old man found in a “thick bed of green algae”, in July 1989, in Saint-Michel-en-Grève (22).
Several other dates are to be remembered. In 1999, scientists from Ifremer and several associations agreed that 95% of the proliferation of green algae comes from excess nitrates from intensive farming. A finding that emerges from a pollution symposium, confirmed by INRA and Ifremer.
In addition, in 2009, several Ministers of State, including Bruno Le Maire and François Fillon, went to the field, in Saint-Michel-en-Grève (22), precisely, recognized the public health risk and ensured that the “ostrich policy”. The first green algae plan is then launched.
But for her, it is the last twist – dated July 2019 – that must be remembered. On this date, the family of the jogger who died in September 2016 in an estuary in the Côtes-d’Armor known for its toxicity linked to green algae has indeed grasped the administrative court of Rennes, accusing the public authorities of having tried to conceal the possible links between the death of this man and the green algae.
Still no click
“In this story, everyone has their truth,” remarks Inès Léraud. “For example, the autopsy of the horse [mort le 28 juillet 2009, ndlr] will give rise to convincing results, but a few months later, the courts are backtracking and relaying a speech in which the green algae have nothing to do with the death of the horse”, explains the journalist.
“It’s a very well-oiled system, and there is a form of complicity on the part of both the public authorities and the industrialists, who are doing everything to preserve Brittany’s main activity: agrifood”, continues Inès Léraud, who compared the slowness of collective awareness with that of the asbestos and pesticide cases.
Still no click so according to her. An opinion shared by the Greenpeace association, which recently protested against the plan to combat green algae, which “is useless if we do not attack the cause of the problem, the ultra- productivist of the region”, could we read in a press release.
As the institution recalls, “with only 6% of the French agricultural area, Brittany is the first region for the production of milk, eggs and pork, poultry and veal”. “Very strong economic interests are at stake,” adds Inès, who ensures that Breton products are largely destined for export, particularly to Asia and the Middle East.
A reality that has not changed
However, three decades later, and despite the control plan, the proliferation of green algae is still a reality. This summer has even been one of the worst in years. Several Breton bays have again been invaded by green algae, especially in the bays of Morlaix and Saint-Brieuc.
And this, while the presence of nitrate in the water has still not decreased, or too little. According to Inès Léraud, river water should contain around 3 to 4 milligrams of nitrate per liter of water, but it has reached up to 100 milligrams per liter of water in some places.
“Thanks to the policy carried out in recent years, the quantity of nitrates has nevertheless dropped by 20 to 30 milligrams per liter of water, but the objective was to reach 10 milligrams per liter of water”, explains the journalist. who lived more than three years in Brittany, as part of his investigation.
Greenpeace seizes the Council of State
Recently, at the end of July 2019, Greenpeace seized the Council of State about a decree published in December, which aims to simplify the procedures which authorize agricultural operations, in particular breeding. A decree whose association fears the harmful effects it could have on the environment.
“Faced with the crisis and the green tides (here photographed by Philippe Latron), the first measure should be to prohibit any new farm-factories, in particular on Breton territory,” wrote Greenpeace. Traveling to Saint-Brieuc (22) this Thursday, July 25, where the only beach is closed to the public because of this pollution, MEP Yannick Jadot assured that the fight against green algae “was not at all up to the challenge”.
“We need a complete change in the agricultural model […]. We cannot say that ‘nothing has been done’ but we cannot say either that ‘this problem will be solved in 10 years, in 20 years’”, added MEP Delphine Batho, also on the spot. While environmental activists are calling for a change in the agricultural model, the association Halte aux tides vertes, whose headquarters are in the bay of Saint-Brieuc (22), continues to mobilize and has launched a new petition at the end of July against the proliferation of these green algae.