It shall be unlawful for any person to keep, hold, or possess in captivity any sick or injured wildlife, except fish, without first obtaining, at no charge, a wildlife rehabilitation permit from the department; provided, however, that such permit shall only be issued to persons determined by the department, based on criteria established by regulation of the board, to be competent and capable of rehabilitating the wildlife for which a permit has been requested; provided, further, that the department shall only issue such a permit when it has determined that the issuance of the permit is in the best interest of the wildlife of this state. If such a permit is issued, the department shall prescribe the term for each such permit and may impose any conditions it determines necessary to ensure adequate public safety and to be in the best interests of the wildlife of this state.