Sch 15 para 20
In section 41(1) of that Act (general definitions) the following definitions shall be inserted at the appropriate places, that is to say— “ fish farm ” has the same meaning as in the Diseases of Fish Act 1937; (b) “ screen ” means a grating or other device which, or any apparatus the operation of which, prevents— (a) the passage of salmon or migratory trout, and (b) if the screen is required in connection with a fish farm, the passage of any fish farmed at that fish farm, or any combination of devices or apparatus which, taken together, achieve that result;