All islands in the Housatonic River and all marshes in or bordering the Housatonic River, extending from the mouth of the river to the upper limits of its tidal fluctuation, are set aside as wildlife habitats and shall be under the exclusive jurisdiction and control of the Commissioner of Environmental Protection. The commissioner shall have the same powers in reference to such islands and marshes as are provided in section 26-16. Such islands or marshes or such portions thereof as are recorded in private ownership shall not be included under the jurisdiction of the commissioner, but such jurisdiction shall extend to all such islands and marshes or portions thereof as are owned or as may be acquired by the state or for the use of the state pursuant to said section 26-16.