3.For the geographical demarcation of the protection and surveillance zones for category A diseases affecting fish, the following minimum requirements must apply:U.K.
the protection zone must be established around an establishment where Epizootic hematopoietic necrosis (EHN) has been confirmed. This zone shall correspond:
in coastal areas: to an area included in a circle with a radius of at least one tidal excursion or at least 5 km, whichever is larger, centred on the establishment in which EHN has been officially confirmed, or an equivalent area determined according to appropriate hydrodynamic or epidemiological data;
in inland areas: to the entire water catchment area of the establishment in which EHN has been officially confirmed. The competent authority may limit the extension of the zone to parts of the water catchment area, or the area of the establishment, provided this does not compromise prevention of the spread of the disease;
the surveillance zone must be established by the competent authority outside the protection zone and must:
in coastal areas: correspond to an area, surrounding the protection zone, of overlapping tidal excursion; or an area, surrounding the protection zone, and included in a circle of radius 10 km from the centre of the protection zone; or an equivalent area determined according to appropriate hydrodynamic or epidemiological data;
in inland areas: be an extended area outside the established protection zone.