Every local port authority shall be administered by a board of port authority commissioners which shall consist of at least seven members; provided, however, that the number of members of one political party shall not exceed the number of members of the other party by more than one. Newly created port authorities as well as those presently constituted shall structure the terms of those commissioners so that no more than three members’ terms shall expire in any one year. The legislative body or county commission of the county or city creating the port authority or in the case of a port authority created in this act^* in a constitutional charter city not within a county, the legislative body of that constitutional charter city shall determine the method of appointment, and subject to the limitations expressed in the first sentence of this section, shall determine their qualifications, salaries, powers and duties consistent with the provisions of this chapter. The legislative body or county commission shall also provide for the filing of annual reports by the board of port authority commissioners and for periodic independent audits of the accounts of the port authority.