Your pocket guide to understanding WOAH-listed aquatic animal diseases

The World Organisation for Animal Health (WOAH) has released its first-ever mobile application: Aquatic Animal Diseases Field Guide—a practical field guide that puts essential information on WOAH-listed aquatic animal diseases at users’ fingertips. Built around WOAH’s Aquatic Animal Health Code, the app supports timely recognition, sampling and reporting, helping frontline users strengthen aquatic animal health and biosecurity.

Getting the app?

The mobile Field Guide is designed for quick reference during routine monitoring and in response to suspected disease events.

The app is available on :

Why this app?

Aquaculture is one of the fastest-growing food sectors, and effective prevention and response to disease depends on fast and reliable detection. The app provides ready access to information about aquatic animal diseases listed by WOAH in the Aquatic Animal Health Code.

The diseases covered are WOAH notifiable diseases of international significance which are reportable through the WOAH World Animal Health Information System (WAHIS). The app also includes information on several emerging diseases of fish and crustaceans which have recorded transboundary movements in recent years.

Who it is for

The app is aimed at fishery and aquaculture managers, their field staff, Veterinary Services and aquatic animal health professionals. It serves as a valuable and convenient reference for those involved in national surveillance and monitoring for aquatic animal diseases. The app provides an informative account of the diseases and pathogenic agents that pose a threat to fisheries and the growing aquaculture industry worldwide.

What it includes

Each disease profile summarises the nature of the disease and its causative agents—viruses, bacteria, fungi or parasites—and highlights typical gross signs with photographs to support recognition in the field.

The content aligns with terminology in the WOAH Aquatic Animal Health Code, and is organised by host group (fish, molluscs, crustaceans, amphibians) for quick navigation. Brief sampling checklists guide users on collecting representative animal and environmental samples for laboratory analysis, and the app links directly to the WOAH Manual of Diagnostic Tests for Aquatic Animals for the standard methods used for confirmation.

Field recognition is not a diagnosis

Photographs and visible signs can help an investigator compile a preliminary list of possible diseases—a differential diagnosis. However, gross signs alone are not adequate for definitive diagnosis. Confirmation requires appropriate sampling and laboratory testing using validated methods, as described in the WOAH Manual of Diagnostic Tests for Aquatic Animals. The app emphasises this distinction and points users to the relevant procedures.

Environment matters

Not all disease events are infectious. Morbidity and mortality in aquatic animals can also result from environmental factors such as oxygen depletion, aquatic toxins or sudden changes in temperature or salinity—whether natural or human‑influenced. The app introduces the host–agent–environment interaction that determines whether disease is expressed, helping users consider environmental factors alongside pathogen-focused investigations.

Reporting responsibilities

Fishery and aquaculture managers, farmers and staff should be aware of their responsibilities to rapidly report suspected disease according to their country’s national list of reportable aquatic animal diseases. The app provides information on when to notify and directs users to contact their Competent Authority. Early reporting underpins effective control and helps protect trade and livelihoods.

Contact: WOAH Standards Department ([email protected])

Young-Jin Yang 1), Mun-Gyeong Kwon 1), Jae-Ok Kim 1)
1) National Fishery Products Quality Management Service (NFQS)

The Republic of Korea implements comprehensive disease management of aquatic organisms in accordance with WOAH standards to protect its aquatic ecosystem and ensure a sustainable aquaculture industry. As a result, it has become the first country to have published self-declarations of freedom from diseases not only in fish, shellfish or crustacean species but in all three, and covering the entire territory.

This achievement can be a model for advancing international efforts in aquatic organism disease management. 

Aquatic animal diseases can impact aquaculture, fisheries and the environment, threatening the survival of affected animals. These diseases can spread globally through international trade, posing a major threat to food security in many countries. To minimise this threat, it is important to implement a state-driven disease management system consistent with the WOAH standards.

Aquatic Organism Disease Control Act Since 2008

Under its Aquatic Organism Disease Control Act enacted in 2008, the Republic of Korea has established a systematic aquatic organism disease control, supported by trained personnel and financial resources.

As a national aquatic disease control organisation, the National Fishery Products Quality Management Service (NFQS) has progressively self-declared country freedom from aquatic animal diseases since 2019. This effort aims to prevent the spread of disease within the country, as well as the trade-driven, transboundary transmission of contagious diseases from abroad, adhering to international standards outlined in Chapter 1.4 of the Aquatic Code. 

Aquatic Biosecurity System

The Republic of Korea operates an early detection system that fulfils the requirements specified in Article 1.4.7 of the Aquatic Animal Health Code (Aquatic Code). Its main contents are as follows:

  •  Aqua-farmers and others involved in aquaculture have a legal obligation to immediately report any signs of disease in aquatic organisms to the Competent Authority.
  • The government provides mandatory training to those involved in aquaculture on a regular basis to raise awareness of aquatic organism diseases.
  • Disease surveillance at aqua-farms is conducted by technically trained experts, and all surveillance data are uploaded and maintained in the national integrated network for aquatic organism disease control.
  • Disease identification for clinically infected animals or those sampled during surveillance follows the Manual of Diagnostic Tests for Aquatic Animals (Aquatic Manual).
  • In the event of an aquatic animal disease outbreak, organised disease control measures are implemented to prevent its spread.
  • The country quarantines imported aquatic animals to prevent the introduction of exotic diseases.
Systematic Surveillance of Disease in Aquatic Animals

In general surveillance activities, inspectors conduct interviews and questionnaire surveys to gather information on the history and current disease occurrence status and mortalities. Inspectors visit each farm twice a year during periods when detection is most likely. Samples collected during the visits are sent to laboratories for pathogen testing. The Republic of Korea has over 80 aquaculture species, and aqua-farms for these species undergo approximately 15,000 general surveillance checks annually. Additionally, farms that raise susceptible species designated by WOAH (seven fish, six shellfish, three crustacean and one amphibian species) are subject to 600  targeted surveillance checks each year.

Status on Country Freedom from Aquatic Animal Diseases

Having met the basic biosecurity conditions and based on the results of targeted surveillance activities over the last 15 years, the Republic of Korea self-declared its entire territory free from infectious salmon anaemia in 2019, infection with Gyrodactylus salaris in 2020, infection with abalone herpesvirus in 2021, infection with infectious hypodermal and haematopoietic necrosis virus in 2022, infection with salmonid alphavirus in 2023, and infection with yellowhead virus genotype 1 in 2024. These results demonstrate transparency in disease occurrence information, boost animal and public health globally, and enhance trust with fishery trading partners and the international community.       

For aquatic animal diseases, the disease-free status of a country, a zone or a compartment is self-declared. While some Members declare themselves free from certain aquatic diseases, the Republic of Korea undergoes the official administrative and technical screening procedure by WOAH to have its self-declaration published on the WOAH website. This publication objectively demonstrates the country’s status of disease freedom.

To maintain its disease-free status for the six aforementioned disease types, the Republic of Korea continues its disease surveillance activities and upholds its basic biosecurity conditions in accordance with WOAH standards. The country plans to expand its status of disease freedom to a total of ten types of diseases by 2028, promoting the importance of aquatic organism disease control worldwide.

Photo: View of an abalone aquafarm © Ministry of Oceans and Fisheries

As a global authority on animal health, WOAH works to ensure the health of animals and their environments across the world, recognising that animal health impacts everyone’s health. To achieve this, the Organisation recognises the crucial role of research and collaboration in advancing animal health and welfare globally.

In collaboration with STAR-IDAZ, WOAH co-hosted a two-day workshop on advancing research in aquaculture health, with an emphasis on finfish. With key contributions from several sponsors such as the International Development Research Centre (IDRC) and the Australian Department of Agriculture, Fisheries and Forestry, this event aligns with Activity 4.5 of WOAH’s Aquatic Animal Health Strategy.

Bringing together global aquaculture stakeholders—including researchers, funders, and industry leaders—the workshop identified top research priorities that will deliver lasting benefits for managing aquatic animal diseases worldwide, particularly those that will have an impact on international standards. Through dynamic sessions, panel discussions and breakout workshops, participants identified a list of innovative research priorities and practical solutions to strengthen the resilience and sustainability of global aquaculture.

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