Sustainable aquaculture and aquatic resources management

A regional proficiency testing program for aquatic animal disease diagnostic laboratories in Asia-Pacific

Published: 3/8/2015 | 1142 views

A Regional Proficiency Testing Program for Aquatic Animal Disease Diagnostic Laboratories in Asia-Pacific (the ‘regional PT program’) was developed in 2011 to strengthen diagnostic capability across Asia—a region that produces most of the world’s aquatic animal products. This capability was identified as a requirement to facilitate the sanitary safety of trade in aquatic animal products and to assist countries to improve accurate detection of potentially damaging trans-boundary diseases. The need for improved diagnostic capabilities across Asia was widely agreed and documented prior to developing the regional PT program, however few previous activities had made significant or lasting impacts at the regional level.

The regional PT program provided 41 laboratories across the Asia-Pacific with the opportunity to assess their diagnostic performance for 10 regionally significant aquatic animal pathogens, and to adapt or modify practices where necessary to improve. Through collective participation and improvement, regional capability to diagnose important aquatic animal pathogens has been strengthened.

Proceedings of the Expert Consultation on Genetic Erosion Risk Analysis for Shrimp Diseases in Asia

Published: 27/1/2014 | 3146 views

Shrimp aquaculture in tropical regions is facing a disease-induced catastrophe of lost production.  It is estimated that more than 40% of tropical shrimp production is lost to disease annually. The devastating impacts of disease on lost incomes, livelihoods, increased operational costs, trade restrictions and loss of consumer confidence has been a subject of many consultations and policy dialogues.  Discussions of disease crisis have to date been largely focused on identification of pathogens, guidelines and standards for disease detection and surveillance, regulations to limit trans-boundary movement of animals, and adoption of better management practices. 

There is reason to believe that current broodstock management practices may induce genetic erosion that increases susceptibility to disease and vulnerability to epizootics:

  1. Broodstock management as it is currently conducted in SE Asia, particularly by secondary and small-scale hatcheries, is likely to cause rapid accumulation of inbreeding and loss of genetic diversity ("genetic erosion") at farm level;
  2. Inbreeding increases susceptibility to diseases and lowers the threshold for the outbreak of epidemics. This effect may be especially strong in shrimps;
  3. Separately from its correlation with inbreeding, declining genetic diversity also increases the incidence of epizootics (the monoculture effect) and impedes the ability to adapt to stressful environments and changing climate;
  4. These epidemiological effects of climate stress and inbreeding are likely to be multiplicative;
  5. The possible role of genetic erosion in the incidence and prevalence of diseases and epizootics are not included in current discussions of the disease problem in tropical aquaculture.

The basic tenet for this Expert Consultation is that an important aggravating factor in the disease crisis is an agro-economic system that locks shrimp breeders, hatcheries and farmers into behaviour that induces high levels of inbreeding.  If inbreeding does increase the severity and frequency of epidemics, this disease crisis will only get worse over vast areas of Asia, Central and South America, Africa and the Middle East until  it is addressed.

This Expert Consultation was organized in conjunction with the annual meeting of the NACA Aquatic Animal Health Advisory Group (NACA-AG) to take advantage of the physical presence and expertise of a small group of world renowned Aquatic Animal Health experts from several national and international institutions. The list of participants and workshop agenda are presented in Annexes 1 and 2.  This consultation is perhaps the first of its kind to bring together a balanced group of experts from diverse fields – epidemiology, microbiology, disease diagnostics & surveillance, aquaculture genetics, fish breeding, and evolutionary biology – to take a fresh, in-depth, and wider perspective on the possible interaction between genetic side-effects of broodstock management and the looming threat of aquatic animal diseases, in particular the contemporary shrimp disease crisis. 

Determinants for WSD outbreaks in Indonesian smallholder shrimp ponds– a pilot study of locality factors, WSSV genotype distributions and pond factors

Author(s): Callinan, R., Whittington, R., Sumarto, B., Toribio, J., Walker, P., Herianto, A., Gudkovs, N., Rooke, E., Murwantoko, Amin, N.N., Taslihan, A., Mustafa, A., Fachry, M.E. | Published: 25/11/2013 | 3007 views

This study focused on events in a representative, 50-pond Indonesian shrimp farming system in Pangkep district, South Sulawesi. Ponds were stocked with Penaeus monodon and the study extended across a single cropping period between May and October 2010. It was designed to improve our understanding of the main causal pathways for white spot disease (WSD), the most serious cause of production loss in these systems. The longitudinal observational study focused on recording the occurrence of different genotypes of the causal infectious agent, white spot syndrome virus (WSSV), in selected components of the system across time, and looking for relationships with pond outcomes, particularly WSD occurrence. We expected that findings would (a) enable relevant Indonesian agencies, and ultimately farmers themselves, to better identify localities suitable for smallholder shrimp farming using better management practice (BMP) programs and (b) inform modification and simplification of these programs, thereby improving both profitability and adoption rates.

Objectives were:

  1. To determine the stability of WSD outbreak-associated WSSV genotypes when passaged through WSSV-free Litopenaeus vannamei, WSSV PCR test-negative P. monodon and selected other WSSV PCR test-negative, non-penaeid hosts;
  2. To identify, using locality-specific environmental data, pond environmental data and data on WSSV genotype distribution and dynamics, the likely determinants for WSD outbreaks at a suitable, broadly representative locality in South Sulawesi.

Our transmission trials showed that genotypy variations did not occur during three sequential passages (four including the preparation of the stock inoculums) in L. vannamei or alternatively in other crustacean hosts. This indicates the genotypes are likely to be sufficiently stable for use in local epidemiological studies during disease outbreaks in shrimp ponds.

WSD outbreaks were recorded in 11 of the study ponds. Outbreaks were attributed to WSSV genotype TRS5 in seven ponds and to genotypes TRS4 and TRS6 in two ponds each. Data analysis showed that:

  • WSSV was ubiquitous at the site. Strategies to prevent WSD outbreaks are probably more useful than trying to prevent WSSV infection in endemic areas.
  • Stocking with WSSV PCR test-negative postlarvae (PLs) supports maintenance of an outbreak-free pond for at least the first two months of production.
  • Once PLs have been excluded as a risk factor for WSSV infection, biosecurity (minimising risk of heavy WSSV exposure post stocking) and environmental factors (management of risk factors for WSD outbreaks) become more important.
  • Water released from WSD outbreak ponds was likely to be an important initiator of disease outbreaks in upstream and downstream ponds;
  • Crabs, wild shrimp, zooplankton and/or polychaetes were not important sources of WSSV infection for WSD outbreaks in farmed shrimp.

These findings suggest that stocking PCR test-negative PLs, coupled with careful management of water intake during nearby WSD outbreaks are the two most useful practice changes farmers can adopt to reduce the risk of outbreaks in their ponds. Establishment of an active, well-resourced and trained extension service, committed to fostering cohesive, informed farmer groups, is the key to enabling these inexpensive practice changes.

FAO/MARD Technical Workshop on Early Mortality Syndrome (EMS) or Acute Hepatopancreatic Necrosis Syndrome (AHPNS) of Cultured Shrimp

Author(s): FAO | Published: 30/9/2013 | 3598 views

Under the auspices of the FAO TCP/VIE/3304 (E) Emergency assistance to control the spread of an unknown disease affecting shrimps, being implemented by Vietnam’s Ministry of Agriculture and Rural Development (MARD), the FAO/MARD Technical Workshop on “Early Mortality Syndrome (EMS) or Acute Hepatopancreatic Necrosis Syndrome (AHPNS) of Cultured Shrimp” held in Hanoi, Viet Nam from 25 to 27 June 2013 was attended by 63 experts and shrimp aquaculture stakeholders from public and private sectors.

The Workshop participants were informed of: (i) relevant findings and outcomes of the work carried out under TCP/VIE/3304 project and (ii) updates on EMS/AHPNS situation and experiences in affected Asian countries. To assist in further understanding this disease in terms of its aetiology additional technical presentations from other experts were given. Nineteen technical presentations provided the basis for discussions on actions and measures to reduce the risk of EMS/AHPNS.

The Workshop recognized that complacency in the shrimp aquaculture sector resulting in that laxity, during a period of relatively trouble-free shrimp production, led to vulnerability of the sector to any newly emerging pathogen that might arise unexpectedly, as is the case of EMS/AHPNS. Poor management practices, weak compliance with standard, good biosecurity and good aquaculture practices both at farm and hatchery facilities were evident. It is now clear that shrimp aquaculture needs to improve and continue to develop into a sector that implements responsible and science-based farming practices.

With the current understanding that EMS/AHPNS has a bacterial aetiology, a strain of Vibrio parahaemolyticus, the Workshop recommended that a proper name be now given to EMS/AHPNS, i.e. acute hepatopancreatic necrosis disease (AHPND).

The Workshop drew a number of recommendations on specific and generic actions and measures for reducing the risk of AHPND, directed to wider shrimp aquaculture stakeholders (public and private sectors) pertinent to important areas such as: AHPND diagnosis; AHPND notification/reporting; international trade of live shrimp, shrimp products (frozen, cooked), and live feed for shrimp; advice to countries affected and not affected by AHPND; measures at farm and hatchery facilities; advice to pharmaceutical and feed companies and shrimp producers; actions on knowledge and capacity development; AHPND outbreak investigation/emergency response; and specific AHPND-targetted research on various themes (i.e. epidemiology, diagnostics, pathogenicity and virulence, public health, mixed infections, non-antimicrobial control measures, environment, polyculture technologies).

Improving biosecurity through prudent and responsible use of veterinary medicines in aquatic food production

Author(s): Bondad-Reantaso, M.G., Arthur, J.R., Subasinghe, R.P. | Published: 3/7/2013 | 1779 views

The current trend towards increasing intensification and diversification of global aquaculture has led to its dramatic growth, thus making aquaculture an important food-producing sector that provides an essential source of aquatic protein for a growing human population. For both developed and developing countries, the sector is recognized as creator of jobs and an important source of foreign export earnings. The expansion of commercial aquaculture, as is the case in commercial livestock and poultry production, has necessitated the routine use of veterinary medicines to prevent and treat disease outbreaks owing to pathogens, assure healthy stocks and maximize production. The expanded and occasionally irresponsible global movements of live aquatic animals have been accompanied by the transboundary spread of a wide variety of pathogens that have sometimes caused serious damage to aquatic food productivity and resulted in serious pathogens becoming endemic in culture systems and the natural aquatic environment. The use of appropriate antimicrobial treatments is one of the most effective management responses to emergencies associated with infectious disease epizootics. However, their inappropriate use can lead to problems related to increased frequency of bacterial resistance and the potential transfer of resistance genes in bacteria from the aquatic environment to other bacteria. Injudicious use of antimicrobials has also resulted in the occurrence of their residues in aquaculture products and, as a consequence, bans by importing countries and associated economic impacts, including market loss, have occurred. As disease emergencies can happen even in well-managed aquaculture operations, careful planning on the use of antimicrobials is essential in order to maximize their efficacy and minimize the selection pressure for increased frequencies of resistant variants. The prudent and responsible use of veterinary medicines is an essential component of successful commercial aquaculture production systems.

The FAO/AAHRI Expert Workshop on Improving Biosecurity through Prudent and Responsible Use of Veterinary Medicines in Aquatic Food Production was convened in Bangkok, Thailand, from 15 to 18 December 2009, in order to understand the current status of the use of antimicrobials in aquaculture and to discuss the concerns and impacts of their irresponsible use on human health, the aquatic environment and trade. Such discussions became the basis for drafting recommendations targeted for both government and private sectors and for developing guiding principles on the responsible use of antimicrobials in aquaculture to be considered as part of future FAO Code of Conduct for Responsible Fisheries (CCRF) Technical Guidelines on Prudent and Responsible Use of Veterinary Medicines in Aquaculture.

Because aquaculture is expected to continue to increase its contribution to the world’s production of aquatic food, offer opportunities to alleviate poverty, increase employment and community development and reduce overexploitation of natural aquatic resources, appropriate guidance to aquaculture stakeholders on the responsible use of veterinary medicines has become essential. Safe and effective veterinary medicines need to be available for efficient aquaculture production, and their use should be in line with established principles on prudent use to safeguard public and animal health. The use of such medicines should be part of national and on-farm biosecurity plans and in accordance with an overall national policy for sustainable aquaculture.

This publication is presented in two parts: Part 1 contains 15 technical background papers presented during the expert workshop, contributed by 29 specialists, and which served as a basis for the expert workshop deliberations; Part 2 contains the highlights of the expert workshop.

Regional proficiency testing program for aquatic animal disease laboratories in Asia-Pacific

Published: 18/11/2012 | 4630 views
This is the report of the first workshop of the Regional proficiency testing program for aquatic animal disease diagnostic laboratories in Asia-Pacific, held from 25-26 July 2012 in Bangkok, Thailand. The workshop was o-organised by DAFF, CSIRO, ANQAP and NACA. Forty-five participants attended the workshop, representing 43 aquatic animal disease diagnostic laboratories from 13 Asia-Pacific countries including Bangladesh, Cambodia, China, Hong Kong, India, Indonesia, Iran, Malaysia, Myanmar, Philippines, Sri Lanka, Thailand and Vietnam. Resource persons were experts from DAFF Australia, CSIRO, ANQAP, NACA and OIE.

There is a strong need for improved aquatic animal disease laboratory diagnostic capability across Asia—the region that produces most of the world’s aquatic animal products. This capability is required to facilitate the sanitary safety of trade in aquatic animal products and to ensure countries can detect potentially damaging transboundary diseases. The need for improved diagnostic capability is widely agreed and documented but few activities have made significant or lasting impact on this issue at the regional level.

Laboratory proficiency testing is an important mechanism for laboratories to test and improve diagnostic capabilities, and participation in a recognised program is usually a requirement for formal laboratory accreditation. There is currently very limited or no access to proficiency testing programs for aquatic animal health laboratories in Asia. In the report of their 2010 meeting, the Regional Advisory Group for Aquatic Animal Health (an advisory group to NACA) provided a status report on the implementation of the Asia Regional Technical Guidelines. In their report, the advisory group noted that ad hoc proficiency testing programs have been run (for a limited selection of diseases and countries) but that there is limited or no access to on-going laboratory proficiency testing programs.

This project will establish a regional laboratory proficiency testing program for aquatic animal diseases of significance to the region. The program will provide access to proficiency testing services from an accredited provider (the Australian National Quality Assurance Program; ANQAP) and will draw on the expertise of the CSIRO Australian Animal Health Laboratory (AAHL) to develop required testing reagents and materials for the program. Below are the general objectives of the programme:

• To strengthen Asia’s regional capability to diagnose important aquatic animal diseases that impact on trade, industry sustainability and/or productivity.

• To train participating laboratory personnel in diagnostic standards, and proficiency testing procedures, and to provide technical assistance to improve laboratory performance.

• To establish a laboratory proficiency testing programme that meets regional needs and which can be accessed following completion of the project.

The first project activity of the programme is this preparatory Workshop hosted by NACA, to train participants on diagnostic standards, proficiency testing procedures, laboratory accreditation and to reach agreement on the panel of tests to be included in the program.

Development of a Regional Research Programme on Grouper Virus Transmission and Vaccine Development

Published: 19/11/2003 | 2792 views
Bondad-Reantaso, MG., J. Humphrey, S. Kanchanakhan and S. Chinabut (eds).

Report of a Workshop held in Bangkok, Thailand, 18-20 October 2000 by the Asia Pacific Economic Cooperation (APEC), Fish Health Section of the Asian Fisheries Society (FHS/AFS), Aquatic Animal Health Research Institute (AAHRI), and Network of Aquaculture Centres in Asia-Pacific (NACA). Bangkok, Thailand. pp 146.

Technical Mission to support Aquatic Animal Health National Strategy in Vietnam

Published: 30/4/2007 | 2048 views
As a part of the ongoing AADCP-RPS project "Strengthening Aquatic Animal Health Capacity and Biosecurity in ASEAN", Technical Mission to Viet Nam was undertaken from 3rd to 9th December 2006, to assist national authorities in the development and implementation of simple and practical national aquatic animal health management strategies.

The mission, coordinated by Aquatic Animal Health Specialist of NACA, was undertaken by a group of 4 regional resource experts. The mission report provides details of the activities accomplished along with recommendations for implementation of national aquatic animal health strategies.

Technical Mission to Myanmar to support implementation of national strategy on Aquatic Animal Health

Published: 30/4/2007 | 1929 views
Technical Mission to Myanmar to support development and implementation of national aquatic animal health strategies was undertaken from 3rd-8th September 2006, as a part of the ongoing AADCP-RPS project "Strengthening Aquatic Animal Health Capacity and Biosecurity in ASEAN". The mission coordinated by NACA, worked with relevant national stakeholders, and developed simple and practical approaches to implement national aquatic animal health strategies in Myanmar.

The introduction of Penaeus vannamei and P. stylirostris

Published: 14/12/2005 | 4489 views

A review of the issues surrounding the translocation and introduction of these species into non-native areas. Topics include the relative advantages and disadvantages of growing these species, introduction of disease, and analysis of regulatory issues in terms of translocation including recommendations for the control of movement and culture of exotic shrimp. This paper was presented at the international workshop "International Mechanisms for the Control and Responsible Use of Alien Species in Aquatic Ecosystems?, 26-29 August 2003, Jinghong, Xishuangbanna, People?s Republic of China.

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