This Decision lays down measures against the outbreaks of highly pathogenic avian influenza in poultry or captive birds to prevent severe economic impacts on poultry farming. Therefore, following an outbreak or outbreaks of highly pathogenic avian influenza in poultry or captive birds, the concerned Member States shall ensure that the surveillance zones established by their competent authorities and the measures to be applied in the surveillance zones, in accordance with Article 21 of Delegated Regulation 2020/687. The Annex of this Decision sets out the list of the concerned Member States, the surveillance zones, and the duration of the measures to be applied in the protection and surveillance zones.