Carrier for growing macroalgae, with an element provided for the growth of seeds deposited thereon, and having elements for suspension in a water volume. The carrier (11) is a sheet provided with apertures (12) allowing the flow of water from one side to the other, the surface of the sheet having a structure which will retain spores and seeds. The invention also comprises an arrangement for suspending such a carrier (11). It comprises connecting means (16) connected to at least one part of an edge (14) of the carrier. It may also be used a platform submersed in the sea, to which the carrier may be attached.