The commissioner may establish fish spawning areas and refuges on any waters; and he may establish closed areas and safety zones on public lands and waters and, with the consent of the owner, on private lands and waters, and close any such area to fishing and trespassing. The commissioner shall have emergency authority to declare a closed season on any species of fish threatened with undue depletion from any cause and, the provisions of § 26-116 notwithstanding, if such cause is any person, firm or corporation engaged in commercial fishing activity, the commissioner shall have the additional emergency power to establish prescribed conditions for the operation of such commercial fishing activity, or suspend or prohibit the right of such person, firm or corporation to operate within such waters for such period of time as the commissioner deems necessary. The commissioner may, if he deems it necessary, close any waters, or portions thereof, in the inland district to fishing for limited periods of time.