(1) As soon as a county bulkhead line as provided in 1s. 253.122 has been fixed by the water and navigation control authority of Pinellas County around the mainland of the county and the offshore islands therein, and the bulkhead line has been formally approved by the Board of Trustees of the Internal Improvement Trust Fund of the state, all in accordance with the provisions of 1s. 253.122, no further change in said bulkhead line shall be made notwithstanding the provisions of 1s. 253.122(5).
(2) It is hereby declared to be the intent of the Legislature that subsection (1) is necessary for the protection of navigable waters in Pinellas County and the fish, wildlife and natural resources therein.