Scallop biomass declines in Seine Bay

The two main French scallop beds are "generally in good condition," despite a 30% decline in the exploitable biomass in the Seine Bay, the largest of the two, according to the French Institute for Research on Exploitation of the Sea (Ifremer).

Exploitable biomass drops to 84,189 tonnes

The total exploitable biomass, which refers to the quantity of scallops measuring 11 cm or more, is estimated at 84,189 tonnes, compared to nearly 120,000 tonnes last year. This decrease in biomass "is a normal interannual fluctuation for a natural population," explained Eric Foucher, a marine biologist at Ifremer, to AFP.

Environmental factors affect scallop survival

During reproduction, "a week of cold weather or very rough sea can cause additional mortality," he added. The new cohort of juveniles (one-year-old scallops), present in large quantities, however, suggests an "exceptional" biomass next year.

Saint-Brieuc Bay shows positive signs

In the Saint-Brieuc Bay, the biomass of scallops that will reach the regulated size (10.5 cm) during the fishing season is expected to reach about 74,700 tonnes during the upcoming season. "If this projection is confirmed, the available biomass will be 5% higher than that of 2025 and will reach a record level," notes Ifremer.

Scallop populations improve over 20 years

Scallop populations in these two bays have significantly improved over the past 20 years due to management efforts, with the improvement of fishing gear selectivity and the limitation of fishing effort. The scallop biomass in the Seine Bay is now almost seven times higher than it was in 2000, according to Mr. Foucher.

Scallop fishery reaches historical peak

The scallop fishery, the first in France, includes 800 vessels and nearly 3,000 fishermen. During the 2025-2026 season, the fishing of this mollusk reached a historical peak with more than 50,000 tonnes of scallops landed in mainland France.