Section 5.8.  Declaration of vacancy in boards or commissions.
   The office of any member of any board or commission created by, or pursuant to, this Charter shall be declared vacant by the council before the expiration of the term of such office:
   (a)   For any reason specified by statute or by this Charter as creating a vacancy in office;
   (b)   If the officer shall be found guilty by a competent tribunal of any act constituting misconduct in office under the provisions of this Charter;
   (c)   If the officer shall miss four consecutive regular meetings of a board or commission or twenty-five percent of such meetings in any fiscal year of the city, unless such absence shall be excused by the board or commission and the reason therefor entered in the proceedings at the time of each absence;
   (d)   If the officer is removed from office by the council in accordance with the provisions of Section 5.9.