Due to the lack of regulation allowing commercial exploitation of abalone (Haliotis tuberculata), French research was directed towards a half extensive aquaculture starting from hatchery juveniles and using the natural production of macrophyte algue of rocky intertidal areas. Spat is produced in the Argenton hatchery (Western Brittany) with an original high density technique (4 000 juveniles of 8 months/m2). About 55 000 juveniles are produced each year and immersed in habitats of 3 types.