STRUCTURE AND ESTABLISHMENT OF MACROPHYTE STANDS ON HARD SUBSTRATA BREEDING TABLE IN THE THAN LAGOON (HERAULT, FRANCE)

The present study deals with the settling of macrophytic populations o n the hard substrates of an oyster breeding table in the ''etang de Th au'' (France, Herault). The colonization was followed over a 19 month period through the quantitative and qualitative study of the biofoulin g collected on plates suspended inside the table. There is an opportun istic development of the populations in time. The results show further more, that there is an existing bathymetric organisation inside the ta ble, characterized by a variation between populations in the surface a nd on the bottom, and a variation between central and peripheral zones . This biological organization is under control of the hydrodynamism, the depth and interspecific competitions.