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Aquatic Diseases

The Marine Institute implements a fish health monitoring programme which tests for diseases listed under Regulation (EU) 2016/429 and other aquatic diseases of national importance.

Diseases listed under Regulation (EU) 2016/429

A synopsis of listed and notifiable diseases, their susceptible and vector species, and Ireland's current health status in relation to each disease can be downloaded here (last updated January 2024).

Below is a summary of listed diseases and categories which they fall under:

Name of Listed Disease Category
Epizootic haematopoietic necrosis [EHN] A+D+E
Viral haemorrhagic septicaemia [VHS] C+D+E
Infectious haematopoietic necrosis [IHN] C+D+E
Infectious Salmon Anaemia [ISA] C+D+E
Koi herpes virus disease [KHV] E
Mikrocytos mackini A+D+E
Perkinsus marinus A+D+E
Bonamia exitiosa C+D+E
Bonamia ostreae C+D+E
Marteilia refringens C+D+E
Taura syndrome virus A+D+E
Yellow head virus A+D+E
White spot syndrome virus C+D+E

Disease Category Definitions

  • Category A disease: a listed disease that does not normally occur in the Union and for which immediate eradication measures must be taken as soon as it is detected.
  • Category B disease: a listed disease which must be controlled in all Member States with the goal of eradicating it throughout the Union (no diseases of aquatic animals are currently designated category B).
  • Category C disease: a listed disease which is of some relevance to some Member States and for which measures are needed to prevent it from spreading to parts of the Union that are officially disease-free or that have eradication programmes for the listed disease concerned.
  • Category D disease: a listed disease for which measures are needed to prevent it from spreading on account of its entry into the Union or movements between Member States.
  • Category E disease: a listed disease for which there is a need for surveillance within the Union.


In addition to the listed diseases above, Ireland (or parts thereof) is free from certain diseases affecting aquatic animals and for which there are national measures under Article 226(3) of Regulation (EU) 2016/429, and Commission Implementing Decision (EU) 2021/260:

Gyrodactylus salaris (whole territory)

Spring Viraemia of Carp [SVC] (whole territory)

Bacterial Kidney DiseasE [BKD] (whole territory)

Koi Herpes ViruS [KHV] (whole territory) UPDATE: national measures now apply to KHV as it has been downgraded to a Category E disease in the EU Animal Health Law.


Other Diseases

Apart from the diseases listed under EU legislation, the Fish Health Unit also routinely tests for other diseases which are of economic importance in Ireland. These include: finfish diseases such as Pancreas Disease [PD]Infectious Pancreatic Necrosis [IPN]Furunculosis, Enteric Redmouth and Vibriosis; and shellfish diseases such as Brown Ring Disease, Withering Syndrome and infection with V. aestuarianus. The control of these diseases is on a non-statutory basis.