Fla. Stat. § 8.05
A change in the division of the state into congressional districts shall not vacate or otherwise affect the office of any member of a board or council who is serving at the time such change is effected and who was appointed by reference to a congressional district as it existed immediately prior to the effective date of such change. Any such member serving on such date shall continue to represent the congressional district in which the member resides until the expiration of his or her term. A vacancy shall exist in such board or council in any congressional district in which no existing member resides and the same shall be filled as provided by applicable law. If two or more such members reside in a single congressional district as constituted after such change, each shall be entitled to serve until the expiration of his or her term.
Fla. Stat. § 8.05