Amphibious vehicles greatly facilitate harvesting

The visit by a delegation from the Turkish Ministry of Agriculture and Forestry to oyster and mussel farms in France continued to a mussel farming company cultivating mussels on bouchots, a traditional method in Brittany.

Mussels can be cultivated in beds or on stakes. In France mussels produced on stakes are called bouchot mussels and Brittany is the second largest producer of these after Normandy. Cultivating mussels this way allows a higher density and the mussels are easier to harvest. In addition, they are less vulnerable to predators such as crabs, and they do not contain sand or grit as they are suspended in the water column and not lying on the seabed.

Dramatic tides make for tasty mussels

The Mont St-Michel bay is among the bays in Brittany where bouchot mussels are cultivated. The company Cap à l’Ouest is a member of a group of 43 farmers who all produce mussels. Lines of wooden stakes are arranged in the bay extending from the direction of the shore out to sea. The tide in the bay is impressive as the water travels some 12 km each way so that the 6 m (of which 3 m are buried in sand) high stakes and the mussels they carry are exposed at low tide and almost submerged at high tide. In terms of height there is a 15 m difference between high and low tides, the second highest in the world after the Bay of Fundy in Canada. This movement of the water forces the mussels to open and close encouraging development of the mussel meat and improving its texture. Each tide lasts 12 hours so the mussels are covered by water for half a day and uncovered the other half.

The mussel growing cycle starts with the arrival in summer (May to July) of juvenile mussels attached to ropes. There is no naturally occurring spat in the bay so producers have to buy the juveniles from hatcheries in south Brittany. If the juveniles are very small the ropes are placed in nurseries, special areas where the ropes are stretched horizontally in the water If they are a good size the rope will be attached to the bouchot directly. The mussels take 12-18 months to reach harvest size. As they grow the mussels are enclosed In nets to prevent them from detaching and to protect them from predators. The company tried using biodegradable

Technology reduces time spent harvesting

The Cap à l’Ouest bouchots are located at one end of the bay.

Mussels from the Mont St-Michel bay are certified to the EU’s Protected Designation of Origin (AOP in French).

Since the area is covered in more or less identical bouchots belonging to different companies, identifying the Cap à l’Ouest bouchots is impossible for a visitor. Company employees know the location and there are signs as well. A different method of telling one company’s bouchot from another’s is the way the nets with the mussels are wrapped around the bouchots. In former times the harvesting was manual. To harvest staff would walk out to the bouchots, harvest the mussels and return, a task that would take 12 hours. Today it Is much easier. Amphibious vehicles, boats with wheels, allow the workers to drive to the point where the water starts getting deeper and then switching to boat mode and sailing the rest of the trip. Instead of spending half a day to harvest, it can now be done in six hours. The boat Is equipped with a crane and several large tubs. When the pilot aligns the boat with the bouchots, the crane operator then removes the mussel-containing net from the bouchot and deposits it in a tub. Each bouchot takes about two minutes to harvest.

The mussels would normally be brought back to the factory to be washed, graded, and packed into bags. However, if there are no immediate buyers they are stored in boxes placed on frames at the start of the concession and will be collected the next day. The boxes will be under water when the tide comes in, so they will maintain their quality. The alternative is to take them back to the factory and place them in depuration tanks. Depuration is normally for a minimum of 12 hours, but if the water good quality with a high oxygen content the mussels can remain in the depuration tanks for seven days or more.

PDO designation boosts demand

After being harvested the mussels are brought back to the processing facility where they are washed and graded. Grading divides the mussels into three groups, the largest ones, over 5 cm, are branded Morisseau mussels, a premium product; between 4 and 5 cm the mussels are called bouchot, and those below 4 cm are returned to the sea to grow some more. Some 15 years ago Mr Hesry, the owner of the company, applied for the European protected designation of origin (PDO or AOP in French) label which indicates a strong link between the product and the place it is made. According to the PDO criteria each part of the production, processing, and preparation process must take place in the specific region. According to Mr Hesry, mussels from the Mont St-Michel bay are the only ones in France to sell under an AOP. The mussels are further classified by weight: Morisseau mussels are 100 pieces/kg, while AOP and bouchot mussels are 140 and 160 pieces respectively per kilo. These sizes are also reflected in the price, Morisseau, AOP, and bouchot mussels sell for 3.6, 3.0 and 2.4 euros/kg respectively. While at the retailer the price of the Morisseau mussel is 7 euros/kg.

The crane has an attachment specially developed to harvest the mussels from a bouchot. It takes a minute to remove up to 80 kg of mussels from a stake. A line of bouchots can be seen in the background.

Annual production at Cap à l’Ouest is about 700 tonnes but the mussels are only harvested from June to February. For the remaining months the company imports mussels from other European countries, primarily Ireland but also Jersey, Denmark, and Sweden. The product is sold all around France but is also exported to other European countries (Austria, Germany, Italy, Belgium). Fishmongers, wholesalers, and restaurants are the main buyers, and the product is only delivered in bulk in bags. We do not sell to retailers, Mr Hesry emphasises.

For the company 2022 has not been a good year, he says. Pollution in the water, predation by spider crabs, a lack of rain which

Cap à l’Ouest

D797

35960 Le Vivier-sur-Mer

France

Tel.: +33 2 9948 8592

Owner: Mr Hesry

Activity: Cultivation and trade of mussels

Volumes produced annually: 700 tonnes pushes up the salinity and means less nutrients which in turn affects production of the phytoplankton on which the mussels feed, all affected the yield negatively. Predation by spider crabs this year has been the worst we have seen in the last 25 years.

The Turkish delegation found the trip to the mussel farm interesting and useful. Whether the representatives’ visit will trigger the introduction of bouchots to Turkish waters remains to be seen. Other methods of cultivation such as suspending lines from rafts or longlines may be more appropriate for Turkish conditions, but the information gathered in France will have a role to play in the nascent Turkish mussel farming sector.

Brand: Morisseau

Certification: Protected

Designation of Origin (PDO)

Markets: France, Austria, Germany, Italy, Belgium, Singapore, Hong Kong

Product: Bulk packaged in bags

Customers: Fishmongers, wholesalers, restaurants

Employees: 27