Evaluation du stock de praires en rade de Brest - 2001

During the 1950s, the clam played only a bit part in the local maritime context. It was the focus of a different fleet than the king scallop fleet, with a lesser fishing capacity (fleet from the Relecq Kerhuon) and an average annual catch of around 150 tonnes. In the 1960s, with a drop in the king scallop stock, the clam became a substitution resource with productions of over 400 tonnes. The first stages of this evolution are detailed by Le Gall (1969) and Piboubès (1973). Slowly, the fleet developed (from the 70s on, with the progressive arrival of seaweed boats in the fishery) The drop of the production until the disruption of the fishery in the 1980s is the combined consequence of the increase of the fishing capacities with an unfavourable populating demographic strategy (large deposits are fairly rare, as demonstrated in a study by Berthoud (1983) on clam fishery in the Norman-Breton gulf which showed that over a long period, only one age group, born in 1971, withstood the fishery). Many age groups of satisfactory abundance, from the end of the 80s on, combined with a total disruption of the fishery for a few years, lead to a recovery of the stock with fishing levels equivalent (today) to those of the 1950s. The clam, though less iconic than the king scallop in the local context, has now been for a number of years the more important species of the roadstead of Brest in terms of turnover, and thus deserves to be closely looked at. With this in mind, and at the request of the CLPEM, the Ifremer carried out a direct evaluation of the whole population of the Roadstead in spring 2001.