More beaches could be shut in northwestern France due to health fears over toxic algae, conservationists warned on Monday, after it emerged that algae have spread to almost 100 sites in Brittany.
Doctors have warned that the algae pose a health risk as they produce hydrogen sulphide when they rot.
The places under threat include some of the area’s most popular resorts.
Bays popular with Britons from Mont-Saint-Michel along the Atlantic coast all the way to La Baule, a top summer beach destination, are now struggling to dispose of thousands of tons of Ulva lactuca – more commonly known as sea lettuce.
Doctors have warned that the algae pose a health risk as they produce hydrogen sulphide when they rot. That can become trapped under a seaweed crust and be as deadly as cyanide if released suddenly.
Two weeks ago, a horse rider lost consciousness after breathing in the toxic fumes on the beach in Saint-Michel-en-Grève, where 16,000 tonnes of the algae have already been collected this year. His horse was killed.
Pierre Philippe, of the Lannion hospital in Brittany, which also treated a council worker who fell into a coma while clearing beaches, said there were “almost certainly other unreported cases”. The seaweed has been multiplying abnormally fast due to the use of huge amount of nitrates used in intensive pig and poultry farming. The nitrates seep into the region’s rivers and end in the sea. Scientists said global warming could also be a factor.
The worst affected area is Saint-Brieuc on the Côtes-d’Armor coast of Brittany.
Besides Saint-Michel-en-Grève, around ten beaches have been at least partially closed, including Trédrez-Locquémeau and Hillion, according to André Ollivro, vice-president of Halte aux marées vertes (Stop the Green Tides). Other beaches could follow.
“Many town councils are completely overrun by the problem, which is threatening other beaches like Douarnenez and Concarneau – popular tourist spots,” warned Mr Ollivro, who first brought the seaweed to national attention by posing on a beach in a gas mask. The phenomenon was spreading to the south of Brittany and, to a lesser extent, to the popular resort of La Baule, he added. But tourist spots were unlikely to close for political reasons.
In a protest rally on Sunday in Saint-Michel-en-Grève, locals called on the regional government to take emergency action and set up a region-wide early health warning system. The regional prefecture argues it is up to mayors to take the necessary steps to remove the algae or close beaches.
Simply removing truckloads of seaweed would not solve the problem, warned Gilles Huet, from the environmental group Eau et Rivières. “The only answer is to change farming practices in Brittany immediately to reduce the amount of nitrates used and promote sustainable agriculture,” he said.
“There is a pig for every three inhabitants in Brittany, which has 5 per cent of French agricultural land but 60 per cent of the pigs, 45 per cent of the poultry and 30 per cent of the dairy farms,” he said. “The problem is the result of 40 years of misusing the land,” he said.