Status: 08/18/2021 5:42 p.m.
Huge carpets of algae grow on the Breton coast. When these are washed ashore, hydrogen sulfide is produced – a danger to humans and animals. Agriculture is probably also to blame for this.
Armed with a gas mask, André Ollivro trudges across the beach at Hillion in Brittany. There is a pungent odor of rotten eggs over the bay. Sand can no longer be seen. André sinks in with every step. The whole beach is encrusted with a thick layer of beige.
The meter that André attached to his left rubber boot beeps. It measures the concentration of toxic hydrogen sulfide above the beach: 497 ppm (parts per million. One ppm is one per thousand of one per thousand. Editor’s note). Way to high. “Above 25 ppm you have to go, that’s too dangerous. I have to wear my mask and can’t stay that long, these are terrible conditions,” he explains as he trudges away.
André Ollivro on Hillion Beach. He wears a mask because of the high concentration of toxic hydrogen sulfide.
Image: ARD-Studio Paris
Rotting produces gases
Rotting green algae are hidden under the crust on the beach. “When they arrive fresh, they are like lettuce and not poisonous. But when they lie on the beach and decompose under a solid crust, a process begins in which 20 gases are formed,” he explains. Various deaths of humans and animals have been linked to the green alga – also on its beach. “We had 36 dead wild boars, two dogs died before that,” he says. The green alga is a huge problem in Brittany. André has been fighting with his club for more than 20 years “Stop the green tide” on the other hand.
Little is left of the idyllic bay near Saint Brieuc in Brittany. “When I built my hut, I thought that as a pensioner I could fish here and enjoy the beach with my children and grandchildren. But I can forget that,” reports André. Now the beach is closed, once again. It’s just too dangerous.
The problem: excessive agriculture
The green algae have always been around here, but due to climatic changes and high levels of nitrate in the water, the amount has exploded, says André: “That has to do with the fact that we have a large number of fattening farms for pigs, poultry and others Have animals.” Nitrate enters the sea through the rivers – caused by animal manure and fertilizers from intensive agriculture in the region. The nitrate is a kind of energy boost for the algae. They grow like crazy in the shallow bays.
Ineffective anti-algae plans
For more than ten years, various anti-algae plans have been put in place by regional politicians. According to André a good idea, but: “It just wasn’t implemented. Nobody wanted to change anything. Because then agriculture and the population would not have been spared.” Although the nitrate pollution in the waters has decreased somewhat, it is not enough to combat the algae. Some of the nitrate has been in the soil for years and decades.
Yann Yobé no longer wanted to go along with all of this. His yard is ten kilometers from the bay. He has switched his production completely to organic. The cows now only eat grass and hay. Artificial fertilizers are taboo. It was easy for his little farm. “If you want to convert a pig farm to organic, for example, then the stalls have to be demolished. That is much more expensive than conventional agriculture,” he says. Yann is convinced that the bigger a yard, the greater the pollution. Not much will change without financial incentives. “You have to compensate farmers who change something. But that’s not happening at the moment,” said Yobé.
With a bonus system against the algae
This is exactly what they are trying to do in Saint-Michel-en-Grève. The first death associated with green algae occurred 30 years ago. The bay was one of the hardest hit by the green algae. Then they decided on site to help themselves.
François Ponchon is now mayor. Together with farmers in the region, he has developed a bonus system. Who converts gets money. Two thirds of the farmers in the area take part. “The forage should be switched to hay, for example. That removes nitrogen from the soil. This means that less nitrate gets into the rivers – and as a result there is less algae here on the beach,” explains Ponchon. Money comes from various sources, for example from the region or the department.
Algae still have to be cleared away every day on the beach at Saint-Michel-en-Grève. But the situation has gotten much better: 10 years ago it was more than 20,000 tons of green algae per year. Now it’s less than half. Meanwhile, surfers and walkers have returned to the beach.
Image: ARD-Studio Paris
Algae are now a matter for the boss
The beach at André Ollivro’s hut in Hillion will remain closed until further notice due to the green algae. Nevertheless, there is a small success for him: In March, the French Court of Auditors issued an expert opinion that proves that the regional politicians have not acted adequately. The Ministry of Agriculture then made green algae a top priority. André has not yet given up hope that his bay will one day be free of algae.