An artificial seabed (1) for providing a foundation for a marine species cultivation rig (2) wherein the artificial seabed (1) comprises: - an anchoring means (131) for keeping the artificial seabed (1) at a predetermined location with respect to a seabed (5) - a first buoyancy device (11) connectedto the anchoring means (131), the first buoyancy de-vice (11) comprising a receptacle provided with at least one inlet for connecting the receptacle to a surface fluid source, and at least one closable drainage means (111) for allowing the re-placing of at least a part of a first fluid or a second fluid with the second fluid or first fluid, re- spectively, the second fluid having a different density to that of the first fluid, so that the buoyancy of the first buoyancy device (11) is changed for allowing the raising and lowering of the first buoyancy device (11) with respect to the seabed (5). The invention also relates to a cultivation rig (2) comprising the artificial seabed (1), a method for moving an artificial seabed (1) in a body of water by altering the buoyancy of the first buoy-ancy device (11), and a method for moving a cultivation rig (2) in a body of water by altering the buoyancy of the first buoyancy device (11).
