• In the bay of Mont Saint-Michel, undersized mussels that cannot be marketed are at the heart of a battle.

  • Following a court decision, mussel farmers no longer have the right to deposit this waste on the foreshore.

  • Projects are underway to valorize these oversize mussels, which represent between 15 and 30% of annual production.

The amphibious boats are at the dock, the bins stored on the ground empty and the warehouses almost deserted.

In the bay of Mont Saint-Michel, the small port of Vivier-sur-Mer (Ille-et-Vilaine), usually lively, seems very sad on this freezing Friday in January.

With the end of the AOP bouchot mussel season, this high place of mussel farming has been idling for about ten days.

Only a few producers are present to put young mussels back in nets for the next season which will open this summer.

The last was also "complicated" according to the profession, which saw its production fall by 30% compared to the previous harvest.

The fault in particular with the very strong heat of this summer but also and especially with a predator with ten legs.

“For several years, we have witnessed a proliferation of spider crabs which devour mussels and wreak havoc on farms”, indicates Frédéric Hurtaud, producer of AOP mussels in Vivier-sur-Mer and member of the regional committee for shellfish farming in Northern Brittany. .

Tons of mussels piled up on the port of Le Vivier

To make matters worse, the profession also found itself at the heart of a battle this fall.

For decades, mussel farmers have gotten into the habit of throwing small mussels measuring less than four centimeters into the bay, the minimum size required in the AOP specifications.

A practice causing nuisance, visual or olfactory, for local residents but which had never been called into question until now.

Until September 21.

Referred to by two associations, the administrative court on that day suspended the prefectural decree authorizing the spreading of these so-called “undersized” mussels on the foreshore.

The producers then had no choice but to dump their small unsaleable mussels at the entrance to the port of Vivier-sur-Mer.

In a few days, more than a hundred tons of shells were thus piled up to the delight of the gulls.

A little less of the inhabitants who took full nose and lived in the stench for ten days.

15 to 30% of mussels rejected depending on the year

To put an end to their ordeal, a solution was finally found in mid-October with the dispatch of trucks to transport these tons of stinky mussels to Normandy where they were buried.

“A real ecological aberration, fulminates Alain Chevalier, mussel farmer in the bay of Mont-Saint-Michel.

Like him, the whole profession hopes that a new decree will be issued to again authorize the rejection of oversized mussels when the next season opens.

“We don't throw them everywhere either, it's very supervised, underlines Frédéric Hurtaud.

And this allows us to fix the gulls in certain places to prevent them from attacking the bouchots.


This controversy has shed light on the problem of undersized mussels that no one really knows what to do with.

However, the stakes are high when we know that 15 to 30% of the mussels caught in the bay are thrown back into their natural environment depending on the year.

“Of course, we cannot be satisfied with such waste,” says Alain Chevalier.

The interested food industry

To put an end to this mess, several players are counting on the recovery of these small mussels.

In Pénestin, in the Gulf of Morbihan, the association of Mussella producers has decided to make cooking juice from it for the food industry.

A somewhat similar project is also starting in Cancale where the Mytilimer group, one of the heavyweights in the shellfish sector, has just launched the construction of its new production site.

Called #Kerbone, the project plans to valorize oversized molds in two forms.

“Mussel meat is rich in protein and can be processed for human or animal food, emphasizes Christophe Le Bihan, Managing Director of Mytilimer.

Mussel shell powder is also of interest to certain professions, in particular for the manufacture of glasses.


Not far from there, in Dol-de-Bretagne, the group of producers Cultimer is working on a methanisation project to transform the waste from these bivalves into biogas.

So many development projects that are viewed favorably by the profession.

“If this allows us to find outlets for this waste, we are of course takers”, assures Alain Chevalier.

And too bad if that deprives the gulls of their snack.


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  • Pollution

  • Sin

  • Sea

  • Waste

  • Mont Saint Michel

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  • Brittany

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