A natural oyster reef is declared and defined as not less than one acre in continuous area of any bottoms of any bay, sound, bayou, creek, inlet or any other body of salt or brackish water on which oysters grow naturally, or have grown naturally, in quantity sufficient to warrant fishing for them with hand tongs as a means of a livelihood within a period of five years next preceding the time at which said matter may be presented for consideration and determination by the Director, Marine Resources Division of the Department of Conservation and Natural Resources. But in no case shall an oyster bed be declared or defined to be a natural oyster reef when such bed is located within the limits where the owners of land fronting on such waters where oysters may be grown have the right to create and have created, by artificial means such as planting oysters or oyster shells or by any other means, culture grounds for the growth of oysters and have by these means caused the bottoms on which such beds are located to become hardened so that oysters will grow thereon naturally even though such bed so created exceeds one acre in continuous area and even though after these beds have been artificially created oysters grow naturally thereon, or have grown naturally thereon, in quantity sufficient to warrant fishing for them with hand tongs as a means of livelihood within the period of five years next preceding the time at which said matter may be presented for consideration and determination by the Director, Marine Resources Division of the Department of Conservation and Natural Resources.