DISTRIBUTION OF PECTEN-MAXIMUS (L) AND IT S MAIN POTENTIAL COMPETITORS AND PREDATORS IN THE BAY-OF-BREST

The distributions of Pecten maximus and its potential benthic competit ors and predators in the Bay of Brest were studied from dredge samples to define best areas for seeding of scallop juveniles produced in hat cheries. Negative associations would occur between scallops and their main competitors (segregated distributions), reflecting negative densi ty-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 i n the Bay, when comparing to data from 1954/1955. This would be explai ned by increased sediment silting in several parts of the Bay and/or t he proliferation of scallop competitors (large-sized epifaunal suspens ion feeders) or predators due to benthic community degradation.