J. Richard Arthur
Department of Fisheries and Oceans, Maurice Lamontagne Institute
P.O. Box 1000, Mont-Joli, Quebec, Canada G5H 3Z4
Arthur, J.R. 1996. Fish and shellfish quarantine: the reality for Asia-Pacific. In Health Management in Asian Aquaculture. Proceedings of the Regional Expert Consultation on Aquaculture Health Management in Asia and the Pacific R.P. Subasinghe, J.R. Arthur & M. Shariff (eds.), p. 11–28. FAO Fisheries Technical Paper No. 360, Rome, FAO. 142p.
Abstract
This paper reviews progress made in the Asia-Pacific Region towards establishment of quarantine systems for aquatic organisms. Quarantine programs form part of a first line of defense against possible adverse effects resulting from the introduction or transfer of exotic fish and shellfish. As such, they must be developed within the context of larger national and international plans addressing this problem. “Codes of Practice” for the introduction and transfer of aquatic organisms which have been developed by international organizations provide a starting point for designing national fish health legislation and international agreements to prevent the spread of disease. To succeed, such efforts must be accompanied by the development of regionally agreed-upon lists of certifiable pathogens, the standardization of diagnostics techniques and the production of health certificates of unambiguous meaning. Strong commitment by national governments and the cooperation of importers/exporters are considered key elements in the success of these programs. Successful disease prevention will also be directly related to the ability of countries to reduce their dependence on imported broodstock and fry for the aquaculture industry, and shipments for the ornamental fish trade, particularly those involving wild-caught fishes.
INTRODUCTION
Quarantine can be defined as the holding or rearing of animals under conditions which prevent their escape or the escape of organisms and potential disease agents infecting or associated with them into the natural environment. Quarantine programs for aquatic organisms typically involve protocols for inspection i.e., the examination of animals for disease agents, and certification, the issuing of a certificate stating that a particular lot of animals or a production facility has been inspected and is free from infection by a particular pathogen or pathogens.
Properly designed quarantine programs may be effective at several levels. Internationally and nationally, they are aimed at preventing the spread of exotic species or strains of parasites, bacteria and viruses into countries where they do not occur, while at the sub-national level (state, prefecture, etc.) they help to reduce within-country dissemination of pathogens, be they native or introduced. Finally, at the local level, quarantine of fry and broodstock originating from an outside source helps to protect individual government hatcheries and private fish farms from potentially devastating losses caused by disease, and the conscientious home aquarist from less serious financial setbacks.
At the international and national levels, which are those to which this paper is directed, quarantine programs form an integral part of much broader strategies aimed to protect the natural environment and native faunas from the deleterious impacts of exotic species. They serve the aquaculture industries by protecting them from disease which the industries themselves might introduce when importing fry or broodstock. They also protect human health by preventing the entry and possible establishment of exotic parasites infective to man which are transmitted by aquatic organisms.
INTRODUCTIONS - THE BROAD PICTURE
Ill-considered or accidental introductions of exotic species or strains of aquatic organisms can adversely affect local faunas in a variety of ways. These include genetic pollution, disease introduction and ecological impacts, such as predation, competition and environmental modification (see de Kinkelin et al.. 1985; Sindermann, 1986, 1992; De Silva, 1989; Stewart, 1991; Porter, 1992; Williams and Sindermann, 1992; Carlton, 1993 a,b).
Exotic species are often intentionally introduced, in the hope that they will improve fish production or control nuisance species such as aquatic weeds and mosquitoes. They are also imported for aquaculture purposes and to increase commercial and sport fishing opportunities. Such intentional introductions are done at all levels, ranging from international agencies and national governments to universities, local sportsman's groups and individuals. Accidental introductions also frequently occur, through escapes from culture facilities or backyard ponds (e.g., tropical aquarium fishes) and by transport on boats and in their ballast waters, Indeed, the movement of aquatic organisms in ship's ballast water has recently been recognized as a major cause of undesirable introductions (see Carlton, 1993b), including that of the notorious zebra mussel and the European ruffe into the Great Lakes system in North America.
All wild and most cultured fish and shellfish populations carry parasites, bacteria, viruses and other potential pathogens. When they are moved to new areas, the inevitable result is that disease agents are also transferred, a fact amply documented in the many reports detailing the international spread of fish and shellfish parasites and pathogens as a result of human activities, and their harmful and occasionally devastating effects on native populations (see, for example, Hoffman, 1970; Bauer and Hoffman, 1976; Williams and Sindermann, 1992).
Examples of pathogens which have caused important losses of fish and shellfish in the Asia-Pacific Region and which are believed to be introduced include the copepod Lernaea cyprinacea and myxosporeans of the genus Myxobolus, which have caused problems in Indonesia, Epizootic Ulcerative Syndrome (EUS), which has spread throughout much of South and Southeast Asia, and several viral diseases of penaecid shrimp which are a continuing problem across the region and, indeed, to prawn growers around the world (see Djajadiredja et al., 1983; Lightner, 1985, 1990; Arthur and Shariff, 1991; Lilley et al., 1992).
Economic losses caused by pathogens are difficult to quantify, but are increasingly recognized to be substantial (see Shariff, 1995). For example, Tonguthai (1985) estimated that EUS-caused losses amounted to US$ 8.7 million in Thailand during 1982–1983 alone. More recently, China, which in 1991 was the world's largest producer of farmed shrimp with 200 000 mt, has seen its production reduced by 75% due to a new and possibly exotic disease, China baculovirus (Chamberlain, 1994). It has been estimated that total losses caused by disease in 15 Asian countries in 1990 amounted to at least US$ 1.36 billion, or approximately 6% of the total value of all aquaculture output (ADB/NACA, 1991). Many of the disease agents involved in these losses are known or believed to have been introduced by human activities.
INTERNATIONAL CODES OF PRACTICE
Measures taken by national governments to prevent the introduction of exotic fish and shellfish disease must be develope within the context of larer national and international policies dealing with the introduction and transfer of plants and animals. The Office International des Épizooties (OIE), an international veterinary organization with 139 member countries, has recently developed revised recommendations and protocols for the prevention of the international spread of diseases of aquatic organisms which are given in its new International Aquatic Animal Health Code (S.N. Chen, National Taiwan University, Taipei, pers. comm.). Recommendations for policies dealing with the introduction of aquatic species and guidelines for their implementation, including methods to minimize the possibility of disease transfers, have also been developed by the International Council for the Exploration of the Sea (ICES) for marine introductions (see Anon., 1984; Carlton, 1993c) and the European Inland Fisheries Advisory Commission of the FAO (EIFAC) for transfers of both marine and freshwater organisms (Turner, 1988). More regionally oriented guidelines are provided by the Great Lakes Fish Disease Control Committee of the Great Lakes Fishery Commission (Meyer et al., 1983) and the North American Commission of the North Atlantic Salmon Conservation Organization (Porter, 1992), among others.
An example of such recommendations is the Revised 1990 Code of Practice to Reduce the Risks of Adverse Effects Arising from the Introduction and Transfers of Marine Species which has been developed by the ICES Working Group on Introductions and Transfers of Marine Organisms (see Carlton, 1993c). The ICES Code of Practice is divided into five major parts:
A recommended procedure for all species prior to reaching a decision regarding new introductions;
Recommended action if the decision is taken to proceed with the introduction;
A suggestion that regulatory agencies use the strongest possible measures to prevent unauthorized introductions;
A recommended procedure for introduced or transferred species which are part of current commercial practice; and
A note recognizing that countries will have different attitudes toward the selection of the place of inspection and control of the consignment.
In general, these Codes of Practice and their supporting documents attempt to establish specific diagnostic techniques, define and make known the sanitary regulations of individual countries, develop health certificates whose meanings are unambiguous, and prohibit the international transfer of fish which are not accompanied by these certificates (see de Kinkelin et al., 1985).
The approach relating to disease control in cases of exotic fish introductions as recommended in the EIFAC Code of Practice can be summarized as follows:
Examine each proposed transfer for the possibility of introducing pathogenic organisms and parasites;
Establish a brood stock in the importing country by transfer of eggs to an approved quarantine facility where they will be examined regularly for pathogens;
If no pathogens become evident, transplant first generation progeny, but not the original import, to culture sites or the natural environment;
Continue disease studies on these transplanted individuals.
An important additional step recommended by the ICES Code of Practice is to eliminate the need for further transfers by using F1 individuals to establish a local brood stock.
Such stringent measures are justified to protect existing aquaculture development and avoide harmful effects to indigenous species, both those important to commercial and recreational fisheries and those not currently exploited. The latter may be particularly vulnerable to introduced pathogens, as not having been previously exposed to infection, they often lack natural resistance.
The procedures for fish quarantine recommended in the Code were essentially formulated among developed nations, and have not been widely implemented. Few developing nations have the necessary resources to undertake such stringent measures. Implementation of the Code has sometimes been considered onerous. However, this finding, in itself, indicates that the introduction being contemplated should probably not take place.
PROBLEMS IN IMPLEMENTATION
The implementation of effective quarantine programs by developing countries is difficult due to the high financial requirements and the need for highly trained technical expertise. Some of the requirements are:
Highly trained personnel (fish disease diagnosticians, backed by services in parasitology, virology, mycology, bacteriology and water chemistry);
Adequate diagnostic and quarantine facilities;
Detailed knowledge of potential pathogens, including aspects of their biologies, host specificities, pathologies and geographic distributions;
Detailed knowledge of the indigenous fauna;
Effective legislation;
Adequate enforcement;
Enlightened and cooperative aquaculture and aquarium fish industries;
Existence of a communications network of experts.
In developing countries funds are scarce. The cost/benefit ratio must be high enough to convince government planners of the need for quarantine and inspection services, yet detailed economic analyses of the losses caused by introduced pathogens are few.
Knowledge on fish diseases is restricted to a very few species, less than 2% of the total number known to science (Kinne, 1984). In the Asia-Pacific Region, as elsewhere, little or no information exists for the vast majority of aquatic organisms. Only when basic work on the identities, biologies and distributions of pathogens occurring in the region has been accomplished can meaningful lists of certifiable pathogens be compiled and reliable diagnostic techniques developed.
Aquaculturists and aquarium fish importers all too often regard quarantine and inspection programs as unnecessary evils inflicted upon them by government bureaucracies out to hinder their legitimate business activities. More efforts need to be made to show these groups that such programs will be to their benefit, helping to protect their industries and make them more profitable by reducing losses due to disease. These clients should thus be consulted early on during the development of quarantine and inspection programs, so that they will recognize the need for these programs and support their development and implementation.
PRIORITIES AND NEEDS
Various attempts have been made by regional and international fish health experts to identify priorities for and constraints to the development of quarantine and certification programs for the region and/or to identify needs related to the general development of fish health expertise (see Davy and Graham, 1979; Davy and Chouinard, 1983; Arthur 1987, 1995; Arthur and Shariff, 1991; ADB/NACA, 1991; Langdon et al., 1992). The following list summarizes the recommendations related to legislation and the control of fish diseases made by scientists attending the Asian Development Bank/Network of Aquaculture Centres in Asia (ADB/NACA) Regional Study and Workshop on Fish Disease and Fish Health Management held in Bangkok in 1991 (Wootten, 1991). These experts agreed that countries of the region should:
Prepare legislation to prevent the translocation of serious fish diseases both within and outside the region;
Develop the capability of testing exports of fish to an agreed upon regional standard;
Develop quarantine systems where imports of fish may be tested to regional standards;
Establish a standardized system of disease testing, including a common format of health certificate;
Compile a regional handbook of diagnostic methods;
Quarantine and test for disease, introductions of new species in accordance with the ICES Code of Practice;
Establish a working group of regional and international experts to deal with the above recommendations.
PROGRESS TOWARDS QUARANTINE WITHIN THE ASIA-PACIFIC REGION
This paper focuses primarily on the tropical/sub-tropical areas of the Asia-Pacific and thus considers Australia and Papua New Guinea, and South, Southeast and East Asia. The status of quarantine and certification programs in this region has been summarized on a number of occasions (Davy and Graham, 1979; Davy and Chouinard, 1983; Arthur, 1987, 1995; Arthur and Shariff, 1991; ADB/NACA, 1991). Information presented below for the various countries is summarized mainly from these papers.
Australia and Papua New Guinea
Australia is the only country among those considered herein which has a fully operational quarantine system for imported fishes. The existing system, which was established in 1984, prohibits the entry of live fish unless the species to be imported is listed by the Australian Nature Conservation Agency (ANCA) (formerly the Australian National Parks and Wildlife Service) as being among those aquarium fishes which may be freely imported, or which can be imported under special permit for scientific purposes (see Schmidt and Love, 1985; Humphrey, 1986; O'Connor, 1990; Lehane, 1992). Australia requires that freshwater ornamental fish be accompanied by a declaration of health issued by the exporting country. The premises of the exporter must be inspected regularly, and the exporter certified as competent, by government fish health inspectors of the exporting country. A system of registration of exporters and importers of freshwater ornamental fish has been established and imported freshwater species are held in licensed and inspected quarantine facilities which are provided at the expense of the importer. Fish are held for a minimum of 14 days, during which time they are examined regularly for clinical signs of disease by officers of the Australian Quarantine and Inspection Service (AQIS), the costs of examination being borne by the importer. The AQIS is empowered to require that laboratory examinations be conducted, and does so from time to time. In cases where infected fish are found, the AQIS may treat and reinspect them at the importer's expense, or destroy them without compensation.
Importers and exporters of marine aquarium fishes are not registered (P. Beers, AQIS, Canberra, pers. comm.). Marine species are not quarantined upon arrival, but are inspected to determine their identity, to verify that they are among the species approved for importation, to ensure that they exhibit no clinical signs of disease and to confirm that no other organisms are present in the shipment (Schmidt and Love, 1985; Lehane, 1992). Various regulations also apply to the importation of non-living material derived from or associated with aquatic animals.
The current Australian system, like that in place, in the process of establishment, or being envisioned by various countries of the Asia-Pacific, provides a good practical measure of prevention against the introduction of diseases along with imported aquatic species. Experience has shown that the 14 day quarantine period provides adequate time to allow fish that are incubating diseases or are carriers to become clinically affected (P. Beers, AQIS, Canberra, pers. comm.). However, because the system is based on detection of clinical signs of disease, it can be assumed that parasites, bacteria and viruses often enter the country. Humphrey et al. (1986) have shown that imported ornamental fishes originating from Southeast Asia carry latent bacterial infections exotic to Australia, while Anderson et al. (1993) found viral particles in dwarf gourami (Colisa lalia) imported from Singapore which died in Australian quarantine due to systemic amoebiasis. These authors recommend that inspection for clinical disease during quarantine should be extended to specific health accreditation or random sampling of all imported batches. The AQIS recognizes these shortcomings and in 1992 commissioned a major review of quarantine policy and the disease risks associated with importation of aquatic organisms and their products. The review has been completed and the report is to be released within the next few months (P. Beers, AQIS, Canberra, pers. comm.). The revised policy and quarantine system which will result from this effort should provide a useful model for quarantine development in the rest of the Asia-Pacific.
The status of quarantine and certification programs for Papua New Guinea has been summarized by ADB/NACA (1991) and by Kokolo (1995). Legislation concerning the import/export of aquatic species, including quarantine and certification procedures, is contained in the Animal Disease Control Act and the Fauna Protection Act (Kokolo, 1995).
Papua New Guinea is currently in the process of introducing a number of exotic species in the hope of improving fish production in the Sepik and Ramu River Basin. These include three cold-water species, copper mahseer (Acrossocheilus hexagonolepis), putitor mahseer (Tor putitora) and snow trout (Schizothorax richardsonii); and three warmwater species, tawas (Barbodes gonionotus), pirapatinga (Piaractus brachypomus, syn. Colossoma bidens) and sabalo (Prochilodus lineatus). Introductions are made by importation of live eggs originating from a source where disease-free certification is available. Prior to shipment, the eggs are treated with iodine and upon arrival in PNG, they are kept in quarantine for three months. As PNG currently lacks expertise and facilities for quarantine and disease diagnostics, samples of live fish are sent to overseas laboratories (e.g., University of California at Davis, Universiti Pertanian Malaysia) for disease testing before they are released from quarantine.
Southeast Asia
The situation in Southeast Asia was recently up-dated by Arthur (1995). Three countries, Indonesia, Malaysia and Thailand, have recently made substantial advances.
Indonesia, the first Southeast Asian country to establish a quarantine and inspection service (see Shariff, 1987; Arthur and Shariff, 1991; Arthur, 1995), legislated provisions for a new fish quarantine inspection system in 1992. Staff for the quarantine service have been hired and have received preliminary training, a list of certifiable pathogens has been drawn up, and a blue book of approved diagnostic methods is in preparation. Of six main ports identified for quarantine stations, three (Jakarta, Medan and Pontianak) are still functioning as ports of entry. Importation is done under permit, and a certificate of health issued by the country of origin is required (ADB/NACA, 1991). Fish are supposed to be quarantined for a period of not less than one month, inspected, and if found infected with communicable disease, destroyed. However, due to lack of infrastructure, routine quarantine and inspection of imports have not yet been fully implemented and fish generally receive only visual inspection for signs of disease.
In 1984, Malaysia enacted legislation to control the import and export of fish and to establish quarantine and certification procedures (Ang et al., 1989). The Department of Fisheries (DOF) is establishing four Fish Quarantine and Fish Health Centers under the Sixth Malaysia Plan (1991–1995) (Kechik and Abdulla, 1993). Centers near Subang International Airport, at Tampoi and at Glugor are in operation, while a fourth at Bukit Kayu Hitam will be functional in 1996 (M. Shariff, Universiti Pertanian Malaysia, Serdang, pers. comm.). Under the Seventh Malaysia Plan (1996–2000), additional centers will be constructed at the new Kuala Lumpur International Airport at Sepang, and at Tambak Johor and Labuan. The centers are to implement quarantine of imported aquatic organisms and also issue health certificates for exports at the request of the importing country. The DOF is in the final stages of drawing up rules for import/export and fish quarantine. It has also implemented an inspection program for the premises of individual importers and exporters.
Thailand first adopted legislation restricting the importation of aquatic organisms in 1953. This Royal Decree, subsequently amended in 1982 and made into law in 1983, prohibits the introduction of 176 fish species, 21 invertebrates, and 16 algae (Piyakarnchana, 1989). The Aquatic Animal Health Research Institute (AAHRI), established in 1993 and located in Bangkok, centralizes responsibilities for research on diseases of aquatic animals under one authority. Thailand does not require the inspection or quarantine of imported fishes (Tonguthai, 1987). The fishery's law is currently being revised by the Thai Department of Fisheries and will contain a provision requiring importers to obtain a statement issued by the authorized office of the country of origin attesting to the health status of imported living aquatic animals (K. Tonguthai, AAHRI, Bangkok, pers. comm.). Health certificates for shipments of exported fish are issued at the exporter's request, while hatcheries and holding facilities are occasionally inspected and certified at the request of importing countries, such as Australia.
Considerable fish health expertise also exists in Singapore and the Philippines. Singapore does not consider the importation of exotic species to be a major concern (Cheong et al., 1983; Chou and Lam, 1989). However, Ng et al. (1993) have recently argued that appropriate legislation and quarantine measures are needed to protect its native fish fauna. Quarantine and sanitization procedures, established by the government, are routinely practiced on many farms, but are not compulsory. Ornamental fishes are not inspected upon import, but are examined for clinical signs of disease before export under a health accreditation scheme. As of April 1995, all fish health matters are the responsibility of the newly created Animal and Plant Health Inspection Division (APHID). Singapore plans to formalize a disease surveillance program which will include monitoring of diseases of economic importance (F. Chua, APHID, Singapore, pers. comm.). The Philippines, although having suffered the ravages of Epizootic Ulcerative Syndrome, does not regard establishment of a quarantine and certification program as a high priority. Indeed, as elsewhere, recent legislation designed to remove import restrictions which hamper international trade has worsened the situation (see Arthur, 1995).
Brunei, Kampuchea, Laos, Myanmar and Vietnam all have little expertise or infrastructure related to fish health (see ADB/NACA, 1991), and none of these countries is currently developing quarantine programs for aquatic organisms.
East Asia
No countries in East Asia have implemented programs for the routine quarantine and inspection of imported fishes. Although Japan has vast experience and expertise in fish health, there are no controls on the introduction of aquatic animals based on ecological considerations (Chiba et al., 1989), and fish eggs and juveniles for aquaculture purposes can be freely imported (H. Wakabayashi, University of Tokyo, pers. comm.). No program for the routine quarantine and inspection of imported fishes exists (Kijima, 1990; Ogawa, 1990), however, there is a limited system for the quarantine of fry destined for aquaculture (H. Wakabayashi, pers. comm.). In addition, various recommendations and guidelines to avoid the introduction of fish pathogens from overseas and disease transfer between prefectures have been developed (ADB/NACA, 1991).
Fish health expertise is generally less developed in the other countries of East Asia. The Import and export animal and plant quarantine regulations of the People's Republic of China were implemented in 1982 (ADB/NACA, 1991), followed by other regulations dealing with the import and export of both terrestrial and aquatic animals. Although it has been reported that China follows a strict quarantine procedure when new species are introduced (see Tan and Tong, 1989), given the lack of expertise, infrastructure and detailed knowledge of the pathogens of imported aquatic animals, it is unlikely that this system is effective. The transfer of fish diseases from one region of the country to another is also considered a major problem (ADB/NACA, 1991).
Hong Kong considers strict quarantine to be unworkable, due the nature of the local aquaculture industry, which depends heavily on imported fry, the government's desire to promote free trade and the perception that a quarantine system would be unenforceable and not cost effective (ADB/NACA, 1991). Thus, Hong Kong has no laws related to the quarantine of imported fishes. Korea has some legislation aimed at preventing the import or export of diseased fished (ADB/NACA, 1991), however there does not seem to be provision for routine quarantine and inspection. Taiwan lacks laws governing the importation of aquatic organism (De Silva, 1989). To deal with the risk of disease importation, a health certificate is required from the importing country, as is a pre-inspection by a local veterinarian prior to importation, measures which can, at best, be only partially effective (ADB/NACA, 1991).
South Asia
The situation in South Asia is rather similar to that of East Asia. India, for example, has no legislation on the importation or introduction of aquatic organisms (De Silva, 1989) nor is there a proper quarantine procedure in place for imported fishes (Shetty et al., 1989; ADB/NACA, 1991). The situation in Sri Lanka, Nepal, Pakistan and Bangladesh (Subasinghe and Balasuriya, 1987; De Sliva, 1989; ADB/NACA, 1991i is much the same, some regulations dealing with the import/export of fish and/or fish products having been established, but no effective regulations or procedures for quarantine and inspection existing.
CONCLUSIONS
The effective control of the international spread of fish pathogens remains a distant and elusive goal for much of the Asia-Pacific, as it is elsewhere in many developed and developing countries. Effective national quarantine programs, coupled with a reliable, internationally agreed-upon program of certification of exported aquatic animals at source, would reduce the risk of disease introductions considerably. Given the high costs of disease, both to aquaculture and to artesanal fisheries, such a program would surely result in a net financial savings to the region. Efforts to prevent the international spread of fish disease would be greatly aided if national governments were to severely restrict both the range of aquatic species imported and their numbers.
The progress made by such countries as Australia, Indonesia, Malaysia and Thailand to restrict the international spread of aquatic animal pathogens is laudable. Effective systems take considerable time, effort and resources, and protocols must be developed and modified based on regional experience. New trends towards more effective disease control include a more ecologically based management approach to introductions and transfers via the use of catchment zones (river drainage basins) for freshwater systems and biologically homogeneous coastal zones for marine systems, and the inclusion of crustaceans and molluscs in plans for disease prevention.
For many countries, lack of sufficient political will at the national level seems to be the major problem preventing an effective system to be established. Once national governments give the problem high priority, other constraints (e.g., lack of infrastructure, trained personnel, knowledge, etc.) will be more readily surmounted. In this regard, international organizations such as the OIE, NACA, SEAMEO-BIOTROP and FAO, and regional professional societies, notably the Asian Fisheries Society and its Fish Health Section, should continue to play a key role, highlighting the problem to policy makers and bringing together groups of experts who are capable of working towards solutions.
ACKNOWLEDGEMENTS
I thank the following colleagues for providing information used in the preparation of this paper: Peter Beers, Dick Callinan, Frederic Chua, Kazuo Ogawa, Rohana Subasinghe, Mohamed Shariff and Kamonporn Tonguthai.
REFERENCES
ADB/NACA, 1991. Fish Health Management in Asia-Pacific. Report of a Regional Study and Workshop on Fish Disease and Fish Health Management. Asian Developm. Bank, Agricult. Dep. Rep. Ser. No. 1. Network of Aquaculture Centres in Asia-Pacific. Bangkok, 629 p.
Anderson, I.G., H.C. Prior, B.J.Rodwell and G.O. Harris, 1993. Iridovirus-like virions in imported dwarf gourami (Colisa lalia) with systemic amoebiasis. Austr. Veter. J. 70: 66–67.
Ang, K.J., R. Gopinath and T.E. Chua, 1989. The status of introduced fish species in Malaysia. p. 71–82. In S.S.De Silva. (ed.) Exotic Aquatic Organisms in Asia. Asian Fish. Soc. Spec. Publ. No. 3.
Anon., 1984. Guidelines for implementing the ICES code of practice concerning introductions and transfers of marine species. Intern. Counc. Explor. Sea, Coop. Res. Rep. No. 130, 20 p.
Arthur, J.R., 1987. (ed.) Fish Quarantine and Fish Diseases in South and Southeast Asia: 1986 Update. Asian Fish. Soc. Spec. Publ. No. 1, 86 p.
Arthur, J.R., 1995. Efforts to prevent the international spread of diseases of aquatic organisms, with emphasis on the Southeast Asian Region. In M.Shariff, J.R. Arthur and R.P. Subasinghe. (eds.) Diseases in Asian Aquaculture II. Proceedings of the 2nd Symposium on Diseases in Asian Aquaculture, 24–29 October, 1993, Phuket, Thailand. Asian Fish. Soc., Fish Health Sect., Kuala Lumpur. (In press)
Arthur, J.R., and M.Shariff, 1991. Towards international fish disease control in Southeast Asia. Infofish Intern. 3/91: 45–48.
Bauer, O.N., and G.L.Hoffman, 1976. Helminth range extension by translocation of fish. p. 163–172. In L.A. Page. (ed.) Wildlife Diseases. Plenum Publ. Co., New York.
Carlton, J.T., 1993a. Overview of the issues concerning marine species introductions and transfers. p. 65–67. In M.R.Devoe. (ed.) Introductions & Transfers of Marine Species. Achieving a Balance Between Economic Development and Resource Protection. Proceedings of the Conference & Workshop, October 30 - November 2, 1991, Hilton Head Island, South Carolina. S.C. Seagrant Consortium.
Carlton, J.T., 1993b. Marine species introductions by ships' ballast water: an overview. p. 23–25. In M.R.Devoe. (ed.) Introductions & Transfers of Marine Species. Achieving a Balance Between Economic Development and Resource Protection. Proceedings of the Conference & Workshop, October 30 – November 2, 1991, Hilton Head Island, South Carolina. S.C. Seagrant Consortium.
Carlton, J.T., 1993c. An international perspective on species introductions: the ICES Protocol. p. 31–34. In M.R.Devoe. (ed.) Introductions & Transfers of Marine Species. Achieving a Balance Between Economic Development and Resource Protection. Proceedings of the Conference & Workshop, October 30 – November 2, 1991, Hilton Head Island, South Carolina. S.C. Seagrant Consortium.
Chamberlain, G.W., 1994. Taura syndrome and China collapse caused by new shrimp viruses. World Aquacult. 25: 22–25.
Chiba, K.,Y. Taki, K. Sakai, and Y. Oozeki, 1989. Present status of aquatic organisms introduced into Japan. p. 63–70. In S.S. De Silva. (ed.) Exotic Aquatic Organisms in Asia. Proceedings of a Workshop on Introduction of Exotic Aquatic Organisms in Asia. Asian Fish. Soc. Spec. Publ. 3.
Cheong, L., R. Chou, R. Singh and Chao T. -M., 1983. Singapore, p. 47–63. In F.B. Davy and A. Chouinard. (eds.) Fish Quarantine and Fish Diseases in Southeast Asia. Report of a Workshop held in Jakarta, Indonesia, 7–10 December 1982. Intern. Developm. Res. Centre Publ. IDRC-210e.
Chou, L.M., and T.J.Lam, 1989. Introduction of exotic aquatic species in Singapore. p. 91–97. In S.S.De Silva. (ed.) Exotic Aquatic Organisms in Asia. Asian Fish. Soc. Spec. Publ. No. 3.
Davy, F.B., and A. Chouinard, 1983. (eds.) Fish Quarantine and Fish Diseases in Southeast Asia. Report of a Workshop held in Jakarta, Indonesia, 7–10 December 1982. Intern. Developm. Res. Centre Publ. IDRC-210e, 79p.
Davy, B., and M. Graham, (eds.) 1979. Diseases of Fish Cultured for Food in Southeast Asia. Report of a Workshop held in Cisarua, Bogor, Indonesia, 28 November – 1 December 1978. Inter. Developm. Res. Centre Publ. IDRC-139e, 32 p.
De Silva, S.S., 1989. (ed.) Exotic Aquatic Organisms in Asia. Asian Fish. Soc. Spec. Publ. No. 3, 154 p.
Djajadiredja, R., T.H. Panjaitan, A. Rukyani, A. Sarono, D. Satyani and H. Supriyadi, 1983. Country Reports: Indonesia. p. 19–30. In F.B.Davy and A. Chouinard. (eds.) Fish Quarantine and Fish Diseases in Southeast Asia. Report of a Workshop held in Jakarta, Indonesia, 7–10 December 1982. Intern. Developm. Res. Centre Publ. IDRC-210e.
Hoffman, G.L., 1970. Intercontinental and transcontinental dissemination and transfaunation of fish parasites with emphasis on whirling disease (Myxosoma cerebralis). p. 69–81. In S.F. Snieszko. (ed.) A Symposium on Diseases of Fishes and Shellfishes. Am. Fish. Soc. Spec. Publ. No. 5.
Humphrey, J.D., 1986. Fish health, disease control and aquaculture. p. 107–114. In P. Owen and J.Bowden. (eds.) Freshwater Aquaculture in Australia. Rural Press Queensland Pty Ltd., Queensland.
Humphrey, J.D., C. Lancaster, N. Gudkovs and W. McDonald, 1986. Exotic bacterial pathogens Edwardsiella tarda and Edwardsiella ictaluri from imported ornamental fish Betta splendens and Puntius conchonius, respectively: isolation and quarantine significance. Austr. Veter. J. 63: 369–371.
Kechik, I.A., and S.Z. Abdulla, 1993. Fish quarantine in Malaysia. p. 61–69. In R.P. Subasinghe and M. Shariff. (eds.) Diseases in Aquaculture: the Current Issues. Malaysian Fish. Soc., Kuala Lumpur.
Kijima, T., 1990. Fish disease control plans in Japan. p. 971–972. In R. Hirano and I. Hanyu. (eds.) The Second Asian Fisheries Forum. Asian Fish. Soc., Manila.
de Kinkelin, P., C. Michel and P. Ghittino, 1985. Precis de Pathologie des Poissons. Institut National de la Recherche Agronomique / Office International des Épizooties, Paris, 348 p.
Kinne, O., 1984. Introduction to Volume IV, Part 1: Pisces. p. 1–16. In O. Kinne (ed.) Diseases of Marine Animals. Vol. IV, Part 1. Biologische Anstalt Helgoland, Hamburg, 541 p.
Kokolo, U., 1996. Quarantine practices used in Papua New Guinea for introductions and transfers of live fish. p. 140–142. In R.P.Subasinghe, J.R. Arthur and M. Shariff. (eds.). Health Management in Asian Aquaculture. Proceedings of the Regional Expert Consultation on Aquaculture Health Management in Asia and the Pacific. FAO Fish. Techn. Pap. 360.
Langdon, J.S., G.L. Enriquez and S. Sukimin, (eds.) 1992. Proceedings of the Symposium on Tropical Fish Health Management in quaculture, Biotrop Spec. Publ. No. 48, 172 p.
Lehane, L., 1992. Fish quarantine under scrutiny in 1993. Pet Indust. News, Australia 10: 15–16
Lightner, D.V., 1985. A review of the diseases of cultured penaeid shrimps and prawns with emphasis on recent discoveries and developments. p. 79–103. In Y. Taki, J.H. Primavera and J.A. Llobrera. (eds.). Proceedings of the First International Conference on the Culture of Penacid Prawns/Shrimps. Iloilo City, Philippines, 1984. SEAFDEC Aquacult. Dep., Iloilo.
Lightner, D.V., 1990. Viroses section: introductory remarks. p. 3–6. In F.O. Perkins and T.C. Cheng. (eds.) Pathology in Marine Science. Academic Press, San Diego.
Lilley, J.H., M.J. Philips and K. Tonguthai, 1992. A review of epizootic ulcerative syndrome (EUS) in Asia. Publ. by Aquatic Animal Health Research Institute and Network of Aquaculture Centres in Asia-Pacific, Bangkok, 73 p.
Meyer, F.P., J.W. Warren and T.G. Carey, 1983. A Guide to Integrated Fish Health Management in the Great Lakes Basin. Great Lakes Fish. Comm. Spec. Publ. 83–2, 262 p.
Ng, P.K.L., L.M. Chou and T.J. Lam, 1993. The status and impact of introduced freshwater animals in Singapore. Biol. Conserv. 64:19–24.
O'Connor, P.F., 1990. Introduced fish - the role of the Advisory Committee on Live Fish. p. 21–23. In D.A. Pollard. (ed.) Introduced and Translocated Fishes and the Ecological Effects. Australian Society for Fish Biology Workshop, Magnetic Island, 24–25 August 1989. Bur. Rural Resourc. Proc. No. 8.
Ogawa, K., 1990. Fish parasitology in Japan, its history and recent trends. p. 967–969. In R. Hirano and I. Hanyu. (eds.) The Second Asian Fisheries Forum. Asian Fish. Soc., Manila.
Piyakarnchana, T., 1989. Exotic aquatic species in Thailand. p. 119–124. In S.S. De Silva (ed.) Exotic Aquatic Organisms in Asia. Asian Fish. Soc. Spec. Publ. No. 3.
Porter, T.R., 1992. Protocols for the Introduction and Transfer of Salmonids. North Atlantic Salmon Conservation Organization, North American Commission, NAC (92) 24, 119 p.
Schmidt, M.E., and M.D. Love, 1985. The Australian quarantine system for live ornamental fish. Queensland Agricult. J., Jan.–Feb. 1985, p. 29–31.
Shariff, M., 1987. Current status of programs for fish health certification and quarantine systems. p. 48–52. In J.R. Arthur. (ed.) Fish Quarantine and Fish Diseases in South and Southeast Asia: 1986 Update. Asian Fish. Soc. Spec. Publ. No. 1.
Shariff, M., 1995. Fish health: an odyssey through the Asia-Pacific Region. Syarahan Inaugural, Univ. Pertanian Malaysia, Serdang, 25 p.
Shetty, H.P.C., M.C. Nandeesha and A.G. Jhingran, 1989. Impact of exotic aquatic species in Indian waters. p. 45–55. In S.S. De Silva. (ed.) Exotic Aquatic Organisms in Asia. Proceedings of a Workshop on Introduction of Exotic Aquatic Organisms in Asia. Asian Fish. Soc. Spec. Publ. 3.
Sindermann, C.J., 1986. Strategies for reducing risks from introductions of aquatic organisms: a marine perspective. Fisheries, 11(2): 10–15.
Sindermann, C.J., 1992. Disease risks associated with importation of nonindigenous marine animals. Mar. Fish. Rev.54, No.3: 1–10.
Stewart, J.E., 1991. Introductions as factors in diseases of fish and aquatic invertebrates. Can. J. Fish. Aquat. Sci. 48: 110–117.
Subasinghe, R.P., and L.K.S.W. Balasuriya, 1987. Fish quarantine and certification in Sri Lanka. p. 73–76. In J.R. Arthur. (ed.) Fish Quarantine and Fish Diseases in South and Southeast Asia: 1986 Update. Asian Fish. Soc. Spec. Publ. 1.
Tan Y.-J. and H.-Y. Tong, 1989. The status of exotic aquatic organisms in China. p. 35–43. In S.S. De Silva. (ed.) Exotic Aquatic Organisms in Asia. Proceedings of a Workshop on Introduction of Exotic Aquatic Organisms in Asia. Asian Fish.Soc.Spec. Publ. 3.
Tonguthai, K., 1985. A preliminary account of ulcerative fish diseases in the indo-Pacific Region (a comprehensive study based on Thai experiences). National Inland Fisheries Institute, Bangkok, 39 p.
Tonguthai, K., 1987. Fish quarantine and certification in Thailand. p. 77–84. In J.R. Arthur. (ed.) Fish Quarantine and Fish Diseases in South and Southeast Asia: 1986 Update. Asian Fish. Soc. Spec. Publ. 1.
Turner, G.E. (ed.), 1988. Codes of practice and manual of procedures for consideration of introductions and transfers of marine and freshwater organisms. EIFAC Occas. Pap. No. 23, 44 p.
Williams, E.H. and C.J. Sindermann, 1992. Effects of disease interactions with exotic organisms on the health of the marine environment. p. 71–77. In M Devoc. (ed.) Introductions & Transfers of Marine Species. Achieving Balance Between Economic Development and Resource Protection Proceedings of the Conference & Workshop, October 30 - November 2, 1991, Hilton Head Island, South Carolina. S.C. Seagrant Consortium.
Wootten, R., 1991. Legislation and the control of fish diseases. p. 37–38. In Fish Health Management in Asia-Pacific. Report of a Regional Study and Workshop on Fish Disease and Fish Health Management. Asian Development Bank, Agricult. Dep. Rep. Ser. No. 1. Network of Aquaculture Centres Asia-Pacific, Bangkok.
