In accordance with section 1132(c) of this title, the President shall, no later than June 1, 1983, advise the United States Senate and House of Representatives of his recommendations with respect to the suitability or nonsuitability as wilderness of any area within the lakeshore. Subject to existing private rights, the areas described in the report prepared by the National Park Service entitled "Wilderness Recommendation; Sleeping Bear Dunes National Lakeshore" dated January, 1981, and recommended for wilderness (approximately 7,128 acres) and for potential wilderness additions (approximately 23,775 acres) shall, until Congress determines otherwise, be administered by the Secretary so as to maintain their presently existing wilderness character and potential for inclusion in the National Wilderness Preservation System.