The area of jurisdiction of a port authority created in accordance with Section 2 of this act¹ shall include all of the territory of the political subdivision or subdivisions creating it, together with any other property outside of said subdivision or subdivisions conveyed to it, or over which it exercises control pursuant to Section 6(a) of this act,² or pursuant to the right of eminent domain set forth in Section 6(e) of this act, provided that in no case shall the same area be included in more than one port authority, but the jurisdiction of the port authority first attaching shall be exclusive unless the first attaching shall cede or convey to another.