(1) For any county in which a proposition authorized by RCW 82.14.400 has been passed, there shall be created a zoo and aquarium advisory authority.

(2) The initial board of the authority shall be constituted as follows:

(a) Three members appointed by the county legislative authority to represent unincorporated areas;

(b) Two members appointed by the legislative authority of the city with the largest population within the county; and

(c) Two members jointly appointed by the legislative authorities of the remaining cities within the county representing at least sixty percent of the combined populations of those cities.

(3) Board members shall hold office for whatever terms are determined by their appointing authorities, except that no term may be less than one year nor more than three years, in duration. However, a vacancy may be filled by an appointment for a term less than twelve months in duration.