2.For the geographical demarcation of the protection and surveillance zones for category A diseases affecting molluscs and crustaceans, the following minimum requirements apply:U.K.
(a)
the protection zone must be established in the immediate vicinity of an establishment or group of farming establishments officially confirmed as infected with a category A disease and must correspond to an area determined according to appropriate hydrodynamic and epidemiological data;
(b)
the surveillance zone must be established outside the protection zone and must correspond to an area surrounding the protection zone, determined according to appropriate hydrodynamic or epidemiological data.