All leases of tidelands and beds of navigable waters for the purpose of planting and cultivating oysters, clams, or other edible shellfish shall expressly provide that if at any time after the granting of the lease, the described lands shall cease to be used for the purpose of oyster beds, clam beds, or other edible shellfish beds, they shall revert to and become the property of the state and that the lands are leased only for the purpose of cultivating oysters, clams, or other edible shellfish thereon, and that the state reserves the right to enter upon and take possession of the lands if at any time the lands are used for any other purpose than the cultivation of oysters, clams, or other edible shellfish.