(a)enter and search the hatcheries and fish seed farm at all reasonable times, with such assistance, if any, as he considers necessary, any place in which he has reason to believe that an offence under this Act has been or is being committed and order in writing to the person in possession of any fish seed in respect of which the offence has been or is being committed, not to dispose of any stock of such fish seed for a period not exceeding thirty days or, unless the alleged offence is such that the defect may be removed by the possessor of the fish seed and restrict the stock of such fish seed from being sold;