Southeast Asian Fisheries Development Center
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Transboundary aquatic animal diseases: History and impacts in ASEAN aquaculture
Get PDFAquaculture is one of the important sectors in the economy of most Asia-Pacific countries. However, majority of aquaculture farms are small-scale and most often lack the necessary facilities to comply with or are not well informed of the product standards imposed by concerned authorities, especially for international trade. Most countries in the region have a high reliance on aquatic animals as the major source of protein for their populations. In the past 20 years, farming of shrimp and fish for export has become a major employer and revenue earner for many countries in the region. Aquaculture is a major employer, contributes significantly to national economies, assists in poverty reduction, and is an important element in food security and other national development priorities. Aquaculture has developed rapidly in the region and is now a significant component in the national economies of many countries. However, recent disease events in fish and shrimp farming have indicated that preparedness and response measures are lacking, contributing to spread of disease across large areas of the countries involved.
The growth of aquaculture in recent decades has been dependent on the international movement of aquatic animals and, in particular, the introduction of non-native species. The movement of live aquatic animals and their products has the potential to spread pathogens from one country or region to another, which may result to disease outbreaks. In shrimps as example, most major disease outbreaks were associated with the movement of live animals (broodstock, nauplii and postlarvae) when the patterns of disease spread were analyzed. Many aquatic animal diseases, once established, are often difficult to treat or to eliminate. Over the past 30 years, the Asia-Pacific region has been swept by a number of devastating diseases of aquatic animals which have caused massive economic and social losses. These include spread and outbreaks of infection with Aphanomyces invadans (EUS) in freshwater fish, viral nervous necrosis (VNN) in marine fish, viral hemorrhagic septicaemia (VHS) in marine and freshwater fish, and several viral diseases in shrimps such as white spot disease (WSD), white tail disease (WTD), yellow head disease (YHD) and infectious myonecrosis (IMN) among others. This demonstrates the vulnerability of the aquaculture industry as well as the wild populations to disease emergence in the region. The impacts of these diseases have been aggravated by the lack of effective preparedness and response whenever diseases emerge. Although some national, regional and international actions towards disease emergencies have paved way to disease spread prevention in recent years (e.g. Acute hepatopancreatic necrosis diseases; AHPND), there are still several emerging diseases that need to be considered by aquaculture-producing countries, especially in the ASEAN, through a harmonized and effective emergency preparedness and disease response
Development of specific enzyme-linked immunosorbent assay for yellowtail kingfish (Seriola lalandi) follicle stimulating hormone using recombinant gonadotropins
No full textWe developed a specific competitive enzyme-linked immunosorbent assay (ELISA) for yellowtail kingfish (Seriola lalandi) follicle stimulating hormone (FSH). We previously produced a full-length single chain recombinant yellowtail kingfish FSH using the Pichia pastoris expression system. We used the same method to produce the β subunit of the hormone, against which polyclonal antibodies were raised in rabbits. We first confirmed immunoreactivity of the polyclonal antibodies with the recombinant full length FSH and FSHβ as well as plasma and pituitary FSH of sexually immature and mature yellowtail kingfish by Western blot analysis. We then developed a precise and reproducible ELISA for yellowtail kingfish FSH and validated the assay in plasma and pituitary extracts. The intra- and inter-assay coefficients of variation was <2.2% and 10.2%, respectively. The sensitivity of the assay was 78 pg/ml. For further validation of the assay, we measured the plasma FSH in immature yellowtail kingfish treated with increasing doses (blank, 50, 100 and 150 µg/kg) of kisseptin2-10 peptide from a previous study. The dose response observed in treated females was not significant, however the increased plasma FSH levels coincided with the significantly higher estradiol levels we previously reported in the treated groups. We assessed the applicability of the assay in measuring circulating FSH in other species. We observed parallelism between the linearized FSH standard curve and displacement curves of serially diluted plasma from Atlantic bluefin tuna (Thunnus thynnus) and tilapia (Oreochromis niloticus). We also observed similar parallelism with full length recombinant giant grouper (Epinephelus lanceolatus) FSH. The ELISA we developed for yellowtail kingfish FSH will be useful in understanding the reproductive biology of the species as well as enhancing its aquaculture.This research was funded by grants from the Australian Seafood CRC (2008/745) and the Australian Centre for International Agricultural Research (FIS/2012/101)
Interaction between Rhodobacter sphaeroides and Harmful Algal Bloom (HAB) causing dinoflagellate Amphidinium carterae
No full textThe present study hopes to develop a further understanding regarding algal-bacteria interactions as an option for bioremediation. After the use of chemicals against the events of the red tide proved to be impractical due to its detrimental effects on the aquatic ecosystem, recent studies focused on bioremediation. To examine the algal – bacteria interactions, an in vitro co-culture system consisting of marine bacteria Rhodobacter sphaeroides and HAB – causing dinoflagellate Amphidinium carterae were used as the model organisms. The population count of each species in the co-culture were monitored for 14 days as well as positive (pure A. carterae) control and negative (pure Rb. sphaeroides) control. The co-culture system used for investigating the interactions was established based on the interdependence of the two organisms and later the bacteria would prevail over the dinoflagellate. The results of the population count shows an inverse progression on the growth between the two organisms. Furthermore, the analysis of the populations trend suggests that the bacteria growth was suppressed due to allelopathic interactions by the dinoflagellate specifically the production of toxins and chemical compounds detrimental to the growth of the bacteria proving that the bacteria was ineffective to mitigate the growth of the dinoflagellate
Disaster management practices of academic libraries in Panay island, Philippines: Lessons from typhoon Haiyan
No full textA disaster management plan is essential because it can guide library personnel on what to do in a critical time. Using an eight-part survey instrument, this paper documents the impact of Typhoon Haiyan on 22 academic libraries in Northern Panay, Western Visayas, Philippines and the disaster management practices that were implemented. The results revealed that although the majority of the libraries do not have a disaster management plan, they all had common disaster management practices that enabled them to save parts of their collections. Moreover, the study revealed that librarians lacked knowledge and skills on disaster management. This paper was presented at the 40th International Association of Aquatic and Marine Science Libraries and Information Centers (IAMSLIC) Annual Conference, Noumea, New Caledonia, September 14–18, 2014
Improved survival, prey selectivity and diel feeding cycle of silver therapon Leiopotherapon plumbeus (Perciformes: Terapontidae) larvae reared in tanks with substrate
No full textPhysical substrates in the rearing environment can influence the early survival and feeding patterns of captive-reared fish. In this study, we determined whether substrates affect the survival and growth of hatchery-reared silver therapon Leiopotherapon plumbeus larvae as well as examined their prey selectivity and diel feeding cycle. Newly hatched larvae [1.92 mm total length (TL)] were reared for 40 days in triplicate 4 m3 tanks with or without tropical almond Terminalia catappa leaves as substrate. Prey selectivity of larvae reared in tanks with substrate for 35 days from the yolk-sac stage was measured by the Chesson’s selectivity index (αi). Diel feeding cycle of 3-4 days post-hatch (dph) silver therapon larvae reared in tanks exposed to natural light cycle and fed wild zooplankton was also studied. Larvae reared in tanks with substrate had significantly higher survivorship (48.44 ± 7.85%) than those reared in tanks without substrate (26.73 ± 1.60%). However, total length, specific growth rate and body weight of silver therapon larvae from tanks with or without substrate were not significantly different. Silver therapon larvae are generalist predator, demonstrating a degree of prey selectivity in some prey items during early ontogeny. Prey selectivity of silver therapon larvae varied during larval ontogeny, with higher Chesson’s selectivity index for copepod nauplii among the smaller fish larvae (2–5 dph; 2.94–5.17 mm TL), cladocerans (Moina micrura and Bosmina coregoni) among intermediate (6–11 dph; 5.72–9.60 mm TL), and ostracod, cladoceran and insect larvae among larger fish (12–35 dph; 10.28–20.96 mm TL). Larvae showed a diel feeding cycle where they actively fed during daylight hours, with a peak in the late afternoon, and reached a minimum at dark. Together, these findings advance our understanding of the feeding predatory behavior and efficiency of silver therapon larvae and preference for tanks with substrate that improve their survival.This study was funded by the SEAFDEC Aquaculture Department (Project Nos. Nr-01-F2013B and Br-02-F2015B). The authors are grateful to NB Olorvida for his assistance in the conduct of the experiment. Handling of fish specimens complied with existing regulations of the Philippines
Artificial substratum consisting of poly-β-hydroxybutyrate-based biodegradable plastic improved the survival and overall performance of postlarval tiger shrimp Penaeus monodon
No full textThe use of artificial substratum consisting of poly‐β‐hydroxybutyrate (PHB)‐based biodegradable plastic for penaeid shrimp culture was investigated in the present study. The survival of postlarval tiger shrimp Penaeus monodon (30 ± 5 mg) provided with PHB substratum made out of PHB type DP9002 (Metabolix GmbH, Köln, Germany) was 88.7 ± 3.4% and this was significantly higher as compared to postlarvae provided conventional substratum consisting of polyvinylchloride (PVC) pipes (67.3 ± 6.5%). However, no significant weight improvement was observed for the postlarval tiger shrimp indicating that PHB could not be used as growth promoter. Nevertheless, a trend of improved robustness against adverse environmental conditions (lethal ammonium chloride concentration) and increased resistance to pathogenic Vibrio was observed in postlarval tiger shrimp provided with PHB substratum as compared to postlarvae provided with PVC substratum. Results indicate higher preference by postlarvae on PHB substratum over PVC substratum. Overall, this study indicates the potential of artificial substratum consisting of PHB‐based biodegradable plastic as replacement for conventional substratum consisting of PVC pipes in enhancing the survival of postlarval tiger shrimp and improving its performance against adverse environmental conditions and disease resistance.This study was funded by the Flemish Interuniversity Council (VLIR)
FAO TCP/INT/3501: Emergency preparedness and response systems capacity and performance self-assessment survey
Get PDFThe purpose of this survey is to obtain information on national capacity and the agencies mandated to implement emergency preparedness and response systems with respect to aquatic animal diseases. The results of this survey will help guide regional and national strategic planning with respect to improving aquatic EPR systems, thereby improving aquatic animal health more broadly and assuring adequate and rational support services to achieve sustainable aquaculture development.
This FAO questionnaire on aquatic EPR system capacity and performance is a country level self-assessment survey with four sections: (1) general administration, (2) operational components, (3) support systems and (4) additional information
Evaluation of the bioremediation potential of mud polychaete Marphysa sp. in aquaculture pond sediments
No full textOrganic enrichment from aquaculture could alter the chemical composition of the fishpond bottom by increasing the levels of organic matter (OM), sulfur (S), iron (Fe), and lower pH of the sediment. Polychaetes can contribute to the nutrient cycling and remediation of polluted sediment. A laboratory experiment was conducted to test the remediation potential of small and large mud polychaete Marphysa sp. introduced to two types of fishpond sediment. Initially, Sediment A had lower OM, S, Fe, and higher pH than Sediment B. After 30 days, in Sediment B, large polychaetes significantly decreased the OM level (27%) while both small and large polychaetes promoted significant decreases of S (71%) and Fe (70–73%) in both sediment types. The increase of sediment pH was promoted by the presence of polychaetes (0.53–0.69) although pH level in small polychaete was not significantly different with the no polychaete treatment. Regardless of polychaete treatment, the pH level of Sediment B (1.04 ± 0.10) was significantly improved than that of Sediment A (0.17 ± 0.02). In both sediments, large polychaetes (95%) had better survival rates than small polychaetes (73%). These findings reveal that large Marphysa sp. can significantly improve sediment quality by decreasing the levels of OM, S, and Fe and improve pH level to a more basic form without compromising its survival. Large polychaetes are recommended to be used as bioremediators of organically enriched aquaculture pond sediment.The first author is grateful to the Department of Science and Technology-Science Education Institute Accelerated Science and Technology Human Resource Development Program (DOST-SEI ASTHRDP) and UPV, Office of the Vice Chancellor for Research and Extension (OVCRE) for the scholarship and thesis grant, respectively. The authors are thankful to Vicente T. Balinas (statistician), the staff of Laboratory for Advanced Aquaculture Technology (LFAAT) and Polychaete Production Laboratory (Study Code FD-03-08 T) of SEAFDEC/AQD
OIE international standards on aquatic animals
Get PDFThe World Organisation for Animal Health (OIE) is the intergovernmental organisation responsible for improving animal health worldwide. It is recognised as a reference organisation by the World Trade Organization (WTO) to develop international standards for animal health and zoonoses; as of May 2018, it counts a total of 182 Members.
As the global leader for animal health and welfare standards, the OIE plays an influential role in the prevention, control and information sharing of animal diseases including aquatic animal diseases. The objectives of OIE are to: (1) Ensure transparency in the global animal disease situation; (2) Collect, analyse and disseminate veterinary scientific information; (3) Encourage international solidarity in the control of animal diseases; (4) Safeguard World trade by publishing health standards for international, trade in animals and animal products; (5) Improve the legal framework and resources, national veterinary services and aquatic animal health services; and (6) to provide a better guarantee of food of animal origin and to promote animal welfare.
As an international standard setting organisation, the OIE Aquatic Animal Health Code (the Aquatic Code) provides standards for the improvement of aquatic animal health worldwide. It also includes standards for the welfare of farmed fish and use of antimicrobial agents in aquatic animals. The sanitary measures in the Aquatic Code provide international standards on importing and exporting countries for early detection, reporting and control of pathogenic agents in aquatic animals (amphibians, crustaceans, fish and molluscs) and to prevent their spread via international trade in aquatic animals and their products, while avoiding unjustified sanitary barriers to trade. In addition, to provide a standardised approach to the diagnosis of the diseases listed in the Aquatic Code and to facilitate health certification for trade in aquatic animals and aquatic animal products, the OIE also developed the OIE Manual of Diagnostic Tests for Aquatic Animals.
OIE Aquatic Animal Code chapter 2.1 Import Risk Analysis provide recommendations and principles for conducting transparent, objective and defensible risk for importing aquatic animals and aquatic animal products. The components of risk analysis are 1) hazard identification, 2) risk assessment, 3) risk management and 4) risk communication. Additionally, the OIE international standards (Code and Manual), World Animal Health Information System, and OIE Tool for the Evaluation of Performance of Aquatic Animal Health Services also provide scientific evidence to the MCs on import risk analysis
Emergency preparedness and contingency plans to aquatic animal disease emergencies
Get PDFEmergency preparedness is the ability to respond effectively and in a timely fashion to aquatic animal disease emergencies (e.g. disease outbreaks, mass mortalities). It is a key element of a National Strategy on Aquatic Animal Health and an important consideration of the Progressive Management Pathway for improving Aquaculture Biosecurity.
The important principles, requirements and elements and components of emergency prepareness and contingency plans are briefly described. The emergency preparedness response system audit is also presented as contingency planning arrangements that can provide useful insights and guidance in improving response action to disease emergencies.
The paper concludes that many important lessons and insights learned from dealing with disease epizootics in the early 2000 remains valid after more than two decades when the aquaculture sector continues to be plagued with emerging diseases. Past lessons and more recent experiences demonstrated the value of rapid response, reporting/notification by competent authorities, continuous development of knowledge base and capacities in diagnostics, epidemiology, risk analysis, advanced financial planning and the important roles of governments and producer sectors in co-managing disease outbreak events as they both remain the critical entities responsible for launching rapid response.
Skills and knowledge need to be passed on to locals as they are in the frontline of any disease emergency. Share key lessons from experiences by state and non-state actors (producer and academic sectors and other important players in the value chain), the international players that launch emergency responses, disease investigations and field situation assessments as well as financial entities that support these actions need to be continued. However, we also need to do - a stock taking exercise to evaluate what worked, what did not work, what resources are needed and to understand what are the new drivers for aquatic animal disease emergence in order to move forward with the right and timely response actions to disease emergencies in aquaculture.
Key questions remain: Are we prepared for the next outbreak/mortality event? What are the minimum preparedness and advance preparedness actions needed