Towards a "deal of the century" in Brittany, but this time in the case of green algae?
This is what Eau et Rivières de Bretagne (ERB) wants.
By filing two appeals against the State for "
inaction in the face of water pollution by nitrates
" before the administrative court of Rennes, the association is inspired by the climate legal action which led in 2021 to the condemnation of the State for non-compliance with its commitments to reduce greenhouse gas emissions.
The action of the Breton association, initiated on October 1 and announced on October 10, calls for "
the taking of all useful measures
" to limit nitrate pollution and the "
reparation of ecological and moral damage
", estimated "
at 3.2 million euros
", explains Arnaud Clugery, director and spokesperson for the association.
"
In our estimate, we take into account both the impact on biodiversity, but also the simple fact that people are forced to go further to the beach
," he explains.
The association also announces its resignation from the steering committee of the third Plan for the fight against green algae (PLAV), presented this Friday, October 14 in Rennes in the presence of elected officials from the Regional Council of Brittany.
“
The future plan is not concerted and the State is not deploying additional resources.
So we don't see how the situation can evolve
,” accuses Estelle Le Guern, agriculture project manager at ERB.
90% pollution of agricultural origin
Since 1971, tens of tons of green algae have piled up each summer on the Brittany coast.
As they rot, they release hydrogen sulfide, a deadly gas when exposed to high concentrations.
Many animals have already been found dead, intoxicated.
“
Hydrogen sulfide can cause serious lung damage and lead to death if inhaled in too large quantities
,” explains Philippe Potin, CNRS researcher at the Marine Models Integrative Biology Laboratory (LBI2M).
Due to the dangerousness of this mud, beaches are currently closed to the public.
However, despite the risks, the municipalities have no other choice than to proceed "
to the collection of algae
", explains Estelle Le Guern, who mentions many "
accidents
" during these interventions.
Read alsoGreen algae: the State attacked for ecological damage
According to a 2021 report by the Court of Auditors, this proliferation of green algae is "
more than 90% of agricultural origin
" in the region, where the use of nitrogen fertilizers has increased sharply since the 1960s. come from “
animal excreta
” and “
fertilizers
” used for agriculture, which are then brought by rivers to the beaches.
Brittany is “
the first breeding land in France
”, specifies Estelle Le Guern.
The nitrogen contained in the fertilizers then turns into nitrates, responsible for "
the great proliferation of algae
", she explains.
What leads to "
disruption of the ecosystem
" and prevents "
the development of other marine organisms such as phytoplankton
”.
Nitrogen concentration in Breton rivers rose from less than 5mg/litre in the 1960s to more than 50mg/l on average in the 1990s, earning France two convictions for violating European legislation in 2012 and 2013. Efforts have been made since then, with the rate now standing at 31.7 mg/l on average in the region.
However, well above the 10 mg/l recommended by scientists to get out of this environmental crisis.
In view of the urgency and considering "
the repeated deficiencies [of the State] in the commitment
" against water pollution, the association wants through its two appeals "
to touch the portfolio of the State
", argues Arnaud Clugery.
Contacted, the Brittany region as well as the Ministry of Ecology explain that they cannot respond immediately.
