Recent Submissions

  • Book

    Laboratory manual of standardized methods for antimicrobial sensitivity tests for bacteria isolated from aquatic animals and environment 

    L Ruangpan & EA Tendencia - 2004 - Aquaculture Department, Southeast Asian Fisheries Development Center.
    The manual is one of the important outputs of a collection of studies related to antibiotic usage in order to come up with guidelines for its prudent usage. It offers a complete guide for testing bacterial susceptibility and resistance through the use of simple techniques for disk agar diffusion tests, and a guide to do a more thorough study to test therapeutic levels using microbial inhibitory concentration.
  • Book

    Laboratory manual of standardized methods for the analysis of pesticide and antibiotic residue in aquaculture products 

    IG Borlongan & JNP Chuan - 2004 - Aquaculture Department, Southeast Asian Fisheries Development Center
    The manual contains guidelines on the detection of antibiotic and pesticide residues in aquaculture products. Different methods for the analysis of the two chemicals are discussed. The manual is expected to benefit all those who are involved in the monitoring and enforcement aspects of chemical residue limits in aquaculture products in the region.
  • Book chapter

    Chapter 2. Detection of pesticide residues in aquaculture products 

    IG Borlongan - In Laboratory manual of standardized methods for the analysis of pesticide and antibiotic residue in aquaculture products, 2004 - Aquaculture Department, Southeast Asian Fisheries Development Center
    Agricultural chemicals such as fertilizers and pesticides have made an important contribution to agriculture. Pesticides protect crops from pests and diseases. They have brought about large yield increases, and have helped ensure that the rise in food production has kept well ahead of the rise in population. However, there is a growing concern about the safe use of these chemicals, and the potential dangers to farmers who use them, the environment, and consumers. There is particular concern about pesticides, since almost all chemicals that can kill pests are also potentially damaging to human health.

    Legislation requires that pesticide use is appropriately controlled and maximum residue levels (MRLs) not be exceeded. The level of pesticide residues in food raw materials is a measurable standard. But while residue analysis is essential for companies wishing to assure themselves that their products have been produced in accordance with best practice and within the law, it can be used to greatest effect when targeted at samples most likely to contain residues.

    Reliable residue analytical methods are necessary to measure the magnitude of residue in a seafood, and to enforce legal residue limits (tolerances). Sample preparation and extraction, clean up of extracts and pesticide detection are the main procedures in pesticide residue analysis. There is an interplay among these factors which should be considered in the choice of a particular method.
  • Book chapter

    Chapter 3. Minimal inhibitory concentration (MIC) test and determination of antimicrobial resistant bacteria 

    L Ruangpan - In Laboratory manual of standardized methods for antimicrobial sensitivity tests for bacteria isolated from aquatic animals and environment, 2004 - Aquaculture Department, Southeast Asian Fisheries Development Center
    The agar dilution technique is used to measure qualitatively the in vitro activity of an antimicrobial agent against the test bacteria. In this method, graded amounts of antibiotics are incorporated in agar plates and inoculated in spots with the organisms under study. If the organism under study is susceptible to the incorporated antibiotic, no bacterial growth is expected in agar plates with higher amounts of the drugs. Bacterial growth is observed as the antibiotic concentration in the agar plate diminishes. Inhibition of growth at the minimum or lowest concentration of antibiotic is regarded as the end point.
  • Book chapter

    Chapter 1. Bacterial isolation, identification and storage 

    L Ruangpan & EA Tendencia - In Laboratory manual of standardized methods for antimicrobial sensitivity tests for bacteria isolated from aquatic animals and environment, 2004 - Aquaculture Department, Southeast Asian Fisheries Development Center
    Bacterial isolation, purification and identification are the first steps to bacteriological studies. Isolation is done to obtain pure bacterial cultures. Bacteria are usually isolated from fish kidney and spleen; and from the hepatopancreas, lymphoid organ and muscles of shrimp. These tissues are monitor organs that usually harbor the disease-causing bacteria during infection.
  • Book chapter

    Chapter 2. Disk diffusion method 

    EA Tendencia - In Laboratory manual of standardized methods for antimicrobial sensitivity tests for bacteria isolated from aquatic animals and environment, 2004 - Aquaculture Department, Southeast Asian Fisheries Development Center
    Disk diffusion method is based on the principle that antibiotic-impregnated disk, placed on agar previously inoculated with the test bacterium, pick-up moisture and the antibiotic diffuse radially outward through the agar medium producing an antibiotic concentration gradient. The concentration of the antibiotic at the edge of the disk is high and gradually diminishes as the distance from the disk increases to a point where it is no longer inhibitory for the organism, which then grows freely. A clear zone or ring is formed around an antibiotic disk after incubation if the agent inhibits bacterial growth.
  • Book chapter

    Chapter 1. Detection of antibiotic residues in aquaculture products 

    JNP Chuan - In Laboratory manual of standardized methods for the analysis of pesticide and antibiotic residue in aquaculture products, 2004 - Aquaculture Department, Southeast Asian Fisheries Development Center
    Aquacultured animals are under constant threat from bio-aggressors such as viruses, bacteria, parasites and fungi. These organisms harm either spontaneously or through aquatic animal husbandry practices, and often both. Indeed, it is generally recognized that disease problems follow the development of techniques for animal production.

    Consequently, fish culture uses a variety of chemicals that represent potential threats to the health of the cultured animal, indigenous biota, and even humans. Chemicals employed in aquaculture include the following:

    - Drugs used to treat disease (chemical therapeutants)

    - Chemicals introduced through construction materials

    - Hormones used to alter reproductive viability, sex, and growth rates

    Of these, chemotherapeutic drugs are the most harmful. Chemotherapeutic treatments are initiated after clinical signs of a disease appear in a population of fish. Chemicals used in construction and hormones are not considered because they are relatively non-toxic.

    The use of chemical therapeutants obviously leads to the transit of drugs and to their persistence in products intended for human consumption. It also leads to the release of drugs or their metabolites to the aquatic environment. Hence the criticisms raised in the press against the use of chemotherapy in aquaculture, and the restrictive legislation set up in many countries under pressure of public opinion. It sometimes appears that people would believe that drug resistance of bacteria responsible for human infections originates exclusively, or almost exclusively, from consumption of animal products such as those provided by aquaculture.

    It should be noted that in addition to the chemicals that are deliberately used, fish raised in aquaculture are also susceptible to contamination via pesticides present in feed, agriculture run-off water, and sediments. The magnitude of human exposure to these sources has not yet been fully assessed and should be examined periodically in light of the growth and change in this sector of the seafood industry.
  • Book

    Husbandry and health management of grouper 

    Asia-Pacific Economic Cooperation & Southeast Asian Fisheries Development Center - 2001 - Asia-Pacific Economic Cooperation; SEAFDEC Aquaculture Department
    The groupers (Family Serranidae) are among the most popular species in the live reef food fish industry in the Asia-Pacific region. Groupers are generally fast growing, hardy, suitable for intensive culture, and with excellent characteristics for processing. The high demand for these fishes is due to their unique culinary attributes and scarcity.

    In 1997, the Asia-Pacific region contributed about 90% to the total world aquaculture production. The regional production of farmed grouper was estimated at 15,000 tons, with China as the biggest producer contributing 8,000 tons followed closely by Indonesia. Other countries in the region commonly produce 1,000-2,000 tons annually in 1990- 1997.

    Groupers are generally cultured in floating net cages or earthen ponds, but cage culture is more common in Southeast Asia. Grouper pond production is becoming an attractive alternative to intensive shrimp culture in countries where management problems have forced growers to abandon shrimp farming.

    Although grouper culture is widespread in Asia and the Pacific, its continued development is constrained by the limited availability of fingerlings. Most economies, with the recent exception of Chinese Taipei, rely almost totally on wild-caught fry and fingerlings for stocking. This demand for wild seeds has led to unsustainable and illegal collection practices such as the use of cyanide to capture large numbers of seed with relatively less investment in time and effort.

    The inadequate supply of seed is further aggravated by the lack of appropriate handling techniques during collection, transport and storage of collected fish, and sometimes by an unregulated management of the wild stocks. There is also the lack of appropriate techniques for efficient grouper culture to marketable sizes. A major production constraint is heavy mortality of groupers during the collection and culture phases due to handling stress and diseases.

    The utilization of non-destructive devices for grouper collection, proper fish handling and increased efficiency in culture management can result to socio-economic and environmental benefits. A well-developed grouper culture operation complemented by appropriate wild grouper fishery management can provide sustainable employment to many people – from marginal fishers to farmers to traders. Grouper fisheries based on illegal or destructive fishing practices underlines the urgent need for habitat protection and sustainable utilization of natural resources.

    The objective of this manual is to provide a farmer-friendly practical guide for grouper farmers in the Asia-Pacific economies. It is hoped that this manual will enhance farmers’ ability to culture and handle grouper, as well as to prevent and manage disease outbreaks.