Distribution of Pecten maximus (L.) and its main potential competitors and predators in the Bay of Brest

Abstract : The distributions of Pecten maximus and its potential benthic competitors and predators in the Bay of Brest were studied from dredge samples to define best areas for seeding of scallop juveniles produced in hatcheries. Negative associations would occur between scallops and their main competitors (segregated distributions), reflecting negative density-dependent relationships between major epifaunal suspension feeders. Highest scallop densities at Roscanvel were not associated with high predator densities, in contrast to the ''Chenal de l'Aulne'' and Caro; this result could signify higher scallop survival in the former zone. Results would indicate a decrease of the area colonized by scallops in the Bay, when comparing to data from 1954/1955. This would be explained by increased sediment silting in several parts of the Bay and/or the proliferation of scallop competitors (large-sized epifaunal suspension feeders) or predators due to benthic community degradation.