France - pollution

France sued for inaction over nitrate pollution, fuel for killer seaweed

Green algae on the Saint-Michel-en-Greve beach in Brittany. The seaweed decomposes and creates toxic gas that is released if an animal or person steps on the dried crust.
Green algae on the Saint-Michel-en-Greve beach in Brittany. The seaweed decomposes and creates toxic gas that is released if an animal or person steps on the dried crust. © David Vincent/AP

A Breton water rights group is suing the French state for not doing enough to lower the amount of nitrate pollution in the Channel, which contributes to the growth of toxic – and sometimes deadly – green algae. 


Green algae on the Breton coast has been a problem since the 1970s, as it washes up on shore and rots, producing hydrogen sulphide, a highly toxic gas that has caused people and animals to fall ill, and sometimes die.

The "killer seaweed" thrives on nitrates, which wash into the sea from the intensive agriculture in the region.

Several local and national plans to reduce the amount of nitrates used and produced by farms have not curbed the problem.

As a result, the group Eau and Rivières (Water and rivers), an NGO that has been working since the 1960s to protect Breton waterways, has filed two lawsuits against the French state in the Rennes administrative court, for not acting against nitrate pollution.

Inspired by climate change case

“We demand that all useful measures be taken and the reparation of ecological and moral damage,” the organisation said in a statement.

The group estimates damages to be 3.2 million euros, due to beach closures and seaweed cleanup activities.

The group’s director Arnaud Clugery said at a press conference that he hopes the amount will “hit the state’s pocketbook” and force it to pay attention.

The strategy of suing the state is inspired by the ‘Affaire du siecle’, in which four NGOs successfully sued the French state in 2021 for not doing enough to reduce greenhouse gas emissions and contributing to climate change.

French state repeatedly condemned

For decades, thousands of tones of nitrate fertiliser and waste from intensive pig farms have polluted eight Breton bays, causing rapid growth of green algae and forcing towns to regularly close beaches.

Eau and Rivières has long been involved in helping local and state authorities come up with plans to reduce nitrate use and runoff, but it has been critical of what it considers the state’s too lenient stance towards the agricultural sector.

The state was condemned in a scathing Senate report in 2021, and a report by the government’s auditor (Cour des Comptes), which called for a fundamental evolution in local agribusiness in Brittany.

In June 2021, the Rennes administrative court ruled in favour of Eau and Rivières, which had filed a suit against the sixth regional plan against green algae.

These rulings lead the group to think that the “planets were aligned to allow for real change”.

But it says it has been kept out of most of the recent discussions.

Pulling out of the process

As the regional council prepares to receive on Friday a third plan (PLAV 3) laying out the state’s policy on how to fight green algae, Eau and Rivières directors announced that they will be stepping down from the plan’s steering committee.

“To be coherent with its legal action, Eau and Rivières announces its refusal to continue its participation,” the group announced.

“The new plan follows the previous one which did not produce significant effects,” Estelle Le Guern, policy officer at Eau and Rivières, said at the press conference, adding that the group’s proposals had been sidelined.

Instead of trying to contain runoff, as the state has done until now, the group would like to see an overhaul of agriculture in the region, using subsidies from the European Union’s Common Agricultural Policy to help shift away from the heavy use of nitrate fertilisers, to more sustainable farming.

“The problem of nitrates in the water, in Brittany as well as in France, cannot be resolved without a real evolution of the agricultural and food processing models,” the group said. “In Brittany, we need to produce less, but better.”

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