Providentiel Coquillage

Circular Economy World Is (in) Your Oyster

Providentiel Coquillages

6. Clean Water and Sanitation 12. Responsible Consumption and Production 14. Life Below Water Flourish Prize Finalist - For Business as an Agent of World Benefit - Weatherhead School of Management


Providentiel Coquillages’s big idea is to re-use the shells of oysters and clams. In particular, in some regions of France, water needs to have minerals added. This can be done by filtering it through crushed oyster and clam shells.





Toulouse Business School

Toulouse Business School





The idea that spurred the founding of Providentiel Coquillages is to respond to the safety problem posed by oyster shell produced by the tonnes of oysters consumed each year by using them in a new form of soft water treatment.

“How can an oyster shell be involved in the soft water treatment process?” one might as. “How, for that matter is soft water a problem in water treatment?” In order to meet the French water quality standards, some regions whose water is too "soft," such as the Toulouse region, must remineralize it before making it accessible to consumers. This pH regulation process is carried out today by injecting lime, soda or sodium carbonate. But, these materials extraction in quarries has a negative impact on the environment. Providentiel Coquillages founders' thinking is as follows: "why extract a natural resource from the earth, when we have a product that naturally possesses minerals and we don't know what to do with it?” This idea has the potential to further several UN Sustainable Development Goals. It comes from the desire to give people clean water (Goal 6), by using responsible techniques of production (Goal 12), and, as we will see it later, to protect life below water (Goal 14).

With the help of an affiliated laboratory, the two founders have developed a technique that aims to remineralize treated water by filtering it through several layers of powder made from crushed oyster and clam shells. This patented technique is now operational. The founders presented their innovation at the Pollutec Occitanie Tradeshow, and their CSR approach enabled them to make contacts with several groups in the water and poultry industries.

The objective for Providentiel Coquillages is to eventually substitute clam and oyster shells for existing soft water treatment techniques. That said, there are many other applications for shells that they are considering. They can also be sold as organic soil amendment, mixed with poultry feed, and included in mulching and gardening products.

Circular Economy World Is (in) Your Oyster


Originally from Cameroon, Daniel Moukoko, one of the founders of Providentiel Coquillages, saw, during his childhood, his grandmother feeding its hens with oyster shells.

A simple question obsessed him: if the hen can be fed with oyster shells, a waste product we usually do not care about, what are the other possible uses of it?

Gaëtan Leguay and Daniel Moukoko then left for adventure to discover all the unbelievable uses of oyster and clam shells. After six months in an incubation program that offers high-tech start-up companies on-site access to laboratories and research expertise, they were contacted by the innovation service of the Occitanie region and the ADEME ( the French Environnement and Energy Management Agency), which then allowed them to launch their activity in 2017 from their headquarters in Ramonville and hire 10 researchers.

Overall impact

Shellfish waste has long been considered a useless byproduct of oyster farming. Until recently, solutions for what to do with it were very limited. The shells were either stored in landfills (where they took up space and the smell caused a nusence), incinerated (which results in a significant CO2 emissions), or dumped in bodies of water.

Dumping them in bodies of water has had disastrous repercussions on aquatic environments, since the accumulation of shells leads to what oyster farmers call "malaïgue," a high concentration of algae that kills shellfish. The Thau Pond epidemic in the Sète region devastated a majority of production in 2003. The collection of shells and their recycling was therefore an major challenge for the sustainability of oyster farming, a key economic activity in the Sète region. The local authorities and the Oyster Farmer Union have therefore set up a collection system based on reciprocity: to sell their oysters, the oyster farmers must adhere to the recycling system.

The example of shellfish waste management in the Thau region is not insignificant. Providentiel Coquillages works closely with this area. Where the startup stands out is thanks to its desire to synergise with local actors. Indeed, they signed a partnership agreement with the stakeholders in the oyster farming business in order to make the most of their waste.

In this way, every year, more than 10 000 tonnes of oyster shells that are collected and transformed just in the Thau area.

Business benefit

To obtain oyster shells, Providentiel Coquillages has four options: collect shells from oyster farmers, collect unsold shells from supermarkets, collect empty shells from restaurants, or shells from private individuals. Given the extent of the sorting required and not yet carried out by local authorities, Providentiel Coquillages only uses deposits from oyster farmers and restaurants. As previously mentioned, the Oyster Farmers Union has had a shellfish waste collection system in place for about 20 years. Until now, oyster aquaculturists had to pay, on average, 2,000 to 3,000 euros per year for waste collection.

Providentiel Coquillages has chosen to subcontract the existing shell collection company. By buying the raw material from the subcontractor, it has lowered the cost of shell pickup and thus reduce costs for oyster farmers by 10%.

Oyster shells are not an expensive raw material, and besides the water treatment business, the demand from the poultry industry is massive. The company is currently fundraising to buy a new machine to increase its level of production and to be able to respond to the huge demand from the poultry industry.

Social and environmental benefit

Shellfish waste, with its multiple possible uses, is a promising market. Rich in limestones and trace elements, they can be used for agronomy, water treatment and cosmetics. The industry for recycling them is still in its infancy.

As Daniel Moukoko reminds us, today, out of 100,000 tonnes of shells produced, only 10% are recycled. The most greatest challenge is convincing distributors and major groups in these sectors that the oyster shells are indeed a reliable product rich in opportunities.

But, the firm wants to go further. Indeed, they would like to create partnerships with supermarket groups to set recycling containers in their stores where consumers could bring back their empty oyster shells. By collecting the oyster waste of the households, the recycling rate would be multiplied at least by 5.

Daniel Moukoko concludes "The idea was to start from a problem, and not only to propose a solution, but also to introduce a wide range of organic consumable goods to the market.”


Daniel Moukoko, Co - founder

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Providentiel Coquillages

Providentiel Coquillages

Ramonville, Occitanie, FR

Business Website:

Year Founded: 2017

Number of Employees: 2 to 10

Providentiel Coquillages is anchored in a circular economy logic. It enhances and transforms the shell of oysters and clams into new products used in poultry feed, soil amendment, mulching and gardening, water treatment and cosmetics.