Two members appointed by the Governor and the members appointed by the Speaker of the House of Representatives and the President of the Senate shall serve for initial terms of two years and until their successors are appointed and qualified. The remaining members appointed by the Governor shall serve for initial terms of four years and until their successors are appointed and qualified. Thereafter, all members shall serve for terms of four years and until their successors are appointed and qualified. Any vacancy among the members so appointed, whether caused by expiration of term, death, resignation, or otherwise, shall be filled in the same manner as the membership position so vacated was last regularly filled. When the vacancy occurs other than by expiration of term, it shall be filled for the unexpired term and until a successor is appointed and qualified.
OCGA § 6-4-5