French scallop stocks are at historically high levels in the Bay of Seine and Saint-Brieuc, but a decline in young shells prompts caution
French Scallop Season Opens with High Stock Levels
The scallop fishing season officially began on 1 October, following scientific assessments by Ifremer which confirm the robust health of scallop populations in France’s two largest scallop beds: the Bay of the Seine and the Bay of Saint-Brieuc.
The levels observed remain at historically high values, providing good news for the country’s leading fishery, which operates around 800 vessels and employs nearly 3,000 fishermen.
Scientific Campaigns Inform Management
As is customary each year, two assessment campaigns are conducted on the main deposits to measure the state of the populations and contribute to their sustainable management.
One took place in the Bay of Seine in July 2025 aboard the Côtes de la Manche, while the other was conducted between the end of August and the beginning of September in the Bay of Saint-Brieuc aboard the Thalia.
Both are coastal vessels of the French Oceanographic Fleet operated by Ifremer and its shipping subsidiary Genavir.
Bay of Saint-Brieuc Biomass Estimated at 70,960 Tonnes
At the start of the season, the biomass of scallops having reached the regulatory size (105 mm since the 2024/25 season) is estimated at 54,550 tonnes. Including the expected growth over the coming months, the biomass available during the entire fishing season will reach approximately 70,960 tonnes.
These figures represent a decrease of seven per cent compared to 2024. Despite this slight decline, the total biomass of all ages amounts to 84,620 tonnes, while the adult biomass—an indicator of the population’s reproductive potential—is estimated at 78,900 tonnes (a three per cent drop compared to 2024). These levels remain historically high, confirming the overall stability of the shell populations.
Seine Bay Reaches 119,482 Tonnes of Available Scallops
In the area between Barfleur (50) and Cap d’Antifer (76), the biomass of scallops of regulation size (110 mm) reached 119,482 tonnes this year, a decline of 13 percent compared to the record figures of 137,000 tonnes last year. This abundance is explained by the arrival of a new large generation of scallops born in 2023 and by the presence of a remainder (shells having survived at least one year of fishing) of 50,475 tonnes, the highest in the historical series since 1980.
Caution Advised Despite Abundance
While the populations remain in good condition, Ifremer researchers Eric Foucher and Spyros Fifas caution that harvests should not be increased.
The good condition is attributed to management efforts implemented by the industry, including improved gear selectivity (97 mm dredging rings since 2017 in North Brittany, extended to the whole of France in 2021) and the limitation of fishing effort through regulated times and periods.
However, researchers observed a decrease in the number of juvenile scallops (less than one year old) compared to previous years. They noted that these are typical interannual variations, but the finding “suggests more limited fishing prospects for the 2026/27 season in the Bay of Seine, and for 2027/28 in the Bay of Saint-Brieuc.”
The scientists concluded that this finding “also shows that it is important not to increase catches, either in terms of fishing effort or the quantities taken, in order to maintain the stability of these populations over the longer term.”
