Victorian Protocol for the Translocation of Eels

Fisheries Victoria Management Report Series

Fisheries Management Report Series No. 27

August 2006

Preferred way to cite this publication: McKinnon, L. (2006) Victorian Protocol for the Translocation of Eels. Fisheries Victoria Management Report Series No. 27.

ISSN 1448-1693

ISBN1 74146 460 9

Introduction

Purpose

The purpose of this protocol is to provide a risk assessment-based guide for the translocation of shortfin (Anguilla australis) and longfin eels (A. reinhardtii) into and within Victoria for the purposes of stock enhancement and aquaculture. This protocol is part of the implementation of the Victorian Eel Fishery Management Plan (VEFMP). This document details the risk assessment process undertaken in relation to the translocation of eels in Victoria and the subsequent controls recommended for the translocation activities associated with the eel fishery in Victoria.

Appendix 1 contains a list of terms used in this document.

Scope

For the purposes of this protocol, translocation is defined as "the deliberate human-assisted movement of a live aquatic organism using associated transport media".

This protocol deals only with the translocation of eels into and within Victoria and only with those practices currently undertaken within the fishery. Specifically, the types of translocation that occur in Victoria and thus considered within the scope of this protocol are detailed in Table 1.

Table 1: Eel translocation activities undertaken in Victoria

Need

Legislation

Key Victorian legislation associated with the translocation of eels includes:

• The Fisheries Act 1995 which regulates the commercial eel fishery, including the stocking of eels in Crown waters, and establishes a number of objectives aimed at achieving ecologically sustainable development with reference to the maintenance of aquatic processes and genetic diversity.
• The Flora and Fauna Guarantee Act 1988, which provides for the protection and conservation of native flora and fauna.

Fisheries Victoria (Department of Environment and Primary Industries) is the lead agency developing a protocol for the translocation of eels in Victoria. All translocation activities described in this protocol must be licensed under the Fisheries Act 1995 and are subject to the Fisheries Regulations 1998. Licences are subject to any conditions specified by the Secretary, Department of Environment and Primary Industries (DEPI).

Policy

The Victorian Aquaculture Strategy (Anon 1998) highlighted the need to "establish a risk management approach to conserve biodiversity" and further established a goal to "ensure ecologically sustainable development". The VEFMP provides the policy framework and support for the management of the Victorian eel fishery including the wild, stock-enhanced and aquaculture sectors. The VEFMP identifies risks associated with eel translocation as having the potential to seriously impact the eel fishery and the aquatic ecosystem. It is therefore recommended, with high priority, that a translocation policy be developed for the eel fishery and aquaculture industry.

The Guidelines for Assessing Translocations of Live Aquatic Organisms in Victoria (Anon 2003) (the Guidelines) provides the policy framework for developing specific guidelines for the translocation of eels into and within Victoria. Where translocations are likely to be repeated and have similar characteristics (i.e. species, associated media and source/destination locations), the Guidelines give preference to the development of approved translocation protocols .

This protocol was developed to fulfil the requirements of the Guidelines.

Industry status

Eels, in particular the shortfin eel, have been translocated within their natural range into and throughout Victoria, for at least forty years. The purpose of such translocations is for enhancement of eel fisheries, mainly in the western part of the state. Translocations have been for the benefit of commercial, and to a lesser extent recreational, eel fisheries with up to 40 percent of the commercial eel catch in Victoria comprising stock enhanced, translocated eels. Translocation of eels into Crown and private waters for stock enhancement purposes is conducted under authority of Aquaculture (Crown Land-Eels) Licences and Aquaculture (Private Land-Eels) Licences, respectively.

The eel fishery, including aquaculture, makes a significant contribution to regional economies, particularly in southwest Victoria. Production is dependent on climatic conditions, particularly rainfall, and in good years the industry produces products valued in excess of $5 million. The majority of product is exported. Increased production of eels using recirculation technology is likely to grow but will depend on the availability of wild-sourced glass eels. There are eighteen Eel Fishery Access Licences (EFAL) issued in Victoria and the industry employs approximately thirty full-time and up to seventy part-time personnel across the State.

Significant quantities of translocated eels are sourced from Tasmania where elvers are collected by the Inland Fisheries Service and sold to licensed fishers and aquaculturists through an expression of interest process. Small eels caught in Victoria by licensed eel fishers may be on-sold to EFAL holders for restocking and permits for the collection and translocation of undersized elvers within Victoria have been issued on request. Prior to export, elvers exported from Tasmania to Victoria and elsewhere are subject to a treatment and monitoring protocol to exclude associated pest species.

Elvers are generally imported into Victoria in plastic bags containing a small amount of water from the holding facility and placed in cardboard or polystyrene boxes. Restock eels and elvers harvested in Victoria are transported in either wet, but not necessarily immersed, mesh bags or in tanks containing water from the original source of the eels.

Risks associated with eel translocation in Victoria

Translocating aquatic organism at its broadest definition encompasses any human assisted movement of that organism. Translocation is recognised as a potential threat to the environment particularly when it involves moving animals outside of their natural range.

In general, the risks associated with the translocation of aquatic organisms are:

• genetic shifts in wild populations;
• establishment of feral populations;
• environmental impacts that result from release of translocated species;
• translocation of associated species;
• introduction of diseases and parasites;
• chemical release; and
• socio-economic impacts from release of translocated species.

As aquaculture and fisheries enhancement present opportunities to utilise a range of species within and outside their natural range in a variety of farming systems, it is important to identify and manage the risks associated with this activity. It is also suggested that the aquaculture and fishing industry sectors take a pro-active role in managing this issue to ensure community confidence is maintained.

The natural range of shortfin and longfin eels in Victoria is shown in Figure 1.

Figure 1: Distribution of shortfin and longfin eels in Victoria by Australian Water Resources Council (AWRC) River Basin.

Summary results of risk assessment

Methodology

A risk assessment was conducted according to the Department of Natural Resources and Environment NRE Risk Management Strategic Framework and Process which is based on the Australian/New Zealand Standard for Risk Management (AS/NZS 4360:1995). An expert panel was convened and facilitated by a qualified risk assessment coordinator and included:

• Mr. Bill Allan, Victorian Eel Fishermen's Association;
• Mr. Anthony Forster, Manager Aquaculture, Fisheries Victoria;
• Dr. Mehdi Doroudi, Director, Marine and Freshwater Systems, PIRVic (Formerly Biosecurity Victoria);
• Mr. Neil Hickman, Marine Scientist, PIRVic (Risk assessment facilitator);
• Mr. Dave Malloy, Marine Scientist, Fisheries Victoria;
• Mr. Lachlan McKinnon, Marine Scientist, PIRVic;
• Mr. Craig Murdoch, Manager Fisheries, South-West Region, Fisheries Victoria; and
• Mr. Bill O'Connor, Policy Officer, Freshwater Biodiversity, Department of Sustainability and Environment.

Assignment of risk categories for the Victorian eel fishery and results of the risk assessment are detailed in Appendix 2. The evaluation of specific risks associated with the translocation of eels was undertaken using standard risk assessment criteria described in the following tables. The likelihood of an event occurring and its consequence are scored and these values added to obtain a risk rating. Risks are then rated as high, significant, moderate or low.

Three specific risks require management controls:

1. "Eel translocations into Victoria from Tasmania could spread disease and parasites" (risk rating of 7);
2. "Shortfin eels outside their natural range will adversely impact biodiversity" (risk rating of 8); and
3. "Longfin eels outside their natural range will adversely impact biodiversity" (risk rating of 9).

Control measures for these risks are detailed in Appendix 2 and summarised as follows:

Disease risks

The risk of disease and or parasites being introduced into Victoria with eels translocated from interstate is managed through:

• pre-export treatment of elvers;
• a declaration provided by the supplier and issued by the Chief Veterinary Office (CVO) or equivalent stating that no evidence of eel mortality or notifiable diseases exists within the past 6 months; and
• visual inspection of each batch of elvers prior to shipment.

The aquaculture licence holder endorsed for eels must obtain a fish health accreditation report prior to bringing eels into Victoria for aquaculture purposes. This report shall be prepared by a veterinarian approved by Victorian Fisheries following a visit to the nursery or holding facility (Appendix 3).

Risks associated with eels outside their natural range

Risks to the environment include escape and establishment of a non-native species into new naive environments with consequent destruction of native species and disruption of their habitats. Facilities that are farming non-native fish must contain these fish within a secure environment. Appendix 4 outlines the requirements to ensure biosecurity of such a facility.

Risks associated with the translocation media

Although this risk is rated as "moderate" industry has volunteered to use only potable (municipal, rain or bore) water as the medium when translocating eels from one catchment to another within Victoria.

In determining the overall risks associated with eels translocated outside of their natural range, it was noted that the consequences of large numbers of longfin or shortfin eels (but particularly longfin eels north of the Great Dividing Range) could be serious long-term or widespread environmental harm. This is due to the large number of listed fish and other potentially vulnerable species in catchments north of the Great Dividing Range, and the longevity and voracious nature of eels, particularly of longfin eels. Such risks are moderated by the catadromous nature of the eel's breeding cycle. Escaped eels will not breed in fresh water and will, therefore, not establish self-sustaining populations.

Translocating eels outside their natural range has been and will continue to be permitted only where the receiving facility is determined to be biosecure according to prescribed guidelines (see Appendix 4), and therefore an "Accredited Aquaculture Establishment".

Existing disease status of eels in Victoria

Although no notifiable diseases of eels have been reported in Australia the risk of their occurrence must be considered. In Victorian waters, Epizootic Haematopoietic Necrosis Virus (EHNV), Epizootic Ulcerative Syndrome (EUS) and an atypical strain of Aeromonas salmonicida are known to occur. According to international scientific literature, eels can be susceptible to EUS but have not been reported as carriers of the infective agent. Eel parasites are not specific to a geographic location; at least one bacterium (Erysoplus) has killed eels but the species is cosmopolitan. Biosecurity Victoria is not currently concerned with translocation of eels within Victoria. A detailed list of eel diseases is presented in Appendix 5.

Protocols for eel translocation in Victoria

Based on outcomes of the risk assessment, key issues were identified and prioritised. Where necessary, control measures have been developed to mitigate the risks of translocating eels.

Translocation of eels into Victoria

This protocol addresses the following translocation activities:

• importing shortfin (Anguilla australis) elvers from Tasmania;
• importing shortfin and longfin (A.reinhardtii) elvers from interstate intensive aquaculture facilities; and
• importing shortfin and longfin glass eels from interstate.

Importation restrictions

• Only shortfin eels and longfin eels may be translocated into Victoria.
• Elvers imported for the purpose of aquaculture must be purchased from an accredited aquaculture establishment as described below.
• Juvenile eels will only be transported to aquaculture licence holders endorsed for eels.
• Prior to translocating eels into Victoria, the requirements outlined in the section entitled "Fish health certification" must be met.
• Elvers must be treated in an antiparasitic bath (formalin and or salt) prior to being transported. Concentrations of formalin and or salt to be determined by the CVO Unit or equivalent.
• No mixing of elvers with other species in holding facilities is allowed.
• Consignments of eels other than for the purpose of aquaculture must be made available for health certification upon request.
• Once eels are imported into Victoria, restrictions applicable to animals translocated within Victoria (described below) will apply.
• Water used to transport eels must be obtained from a municipal, bore or rainwater supply or treated according to the water treatment requirements described in AQUAVETPLAN.
• Water used to transport eels into Victoria must not be discharged into any water body, including streams, lakes, dams, drains and wetlands, within Victoria.
• Dead or moribund eels must not be disposed of in any water body.
• Records of all translocations of eels into Victoria must be kept by the receiver and distributor for a period of three years and copies forwarded to Fisheries Victoria on request. Records must include the source, destination and quantity of eels translocated and dates such translocations took place.

Fish health certification

• The owner of the holding facility must provide a written declaration stating there is no evidence of unexplained mortality.
• A declaration must be issued by the CVO Unit or equivalent that there are no reports of any other notifiable diseases of finfish in the state of origin apart from those published in the most recent Quarterly Report ¨C Australian Aquatic Animal Health.
• A declaration must be issued by the CVO Unit or equivalent stating there has been no recent evidence of major eel mortality and no occurrences of notifiable diseases on the premises of origin reported in the past six months.
• Prior to the shipment, a visual inspection of each batch of eels is required. If there are any obvious clinical symptoms of disease, gross pathological and histopathological examinations of the stock must be carried out by a competent fish pathologist prior to the shipment.
• Prior to translocating eels into Victoria for aquaculture purposes, the aquaculture licence holder endorsed for eels must obtain a fish health accreditation report. This report shall be prepared by a Fisheries Victoria- approved veterinarian following a visit to the nursery or holding facility (refer Appendix 3).
• Each proposed consignment will be assessed for the presence of clinically abnormal fish and include a report describing the history of mortality, an explanation of previous mortality and reference to those samples previously preserved.
• Certification of disease testing of the consignment of eels to be translocated is to be provided to Fisheries Victoria from the relevant veterinarian.
• The cost of preparing the fish health accreditation report will be borne by the proponent. A copy of the report shall be forwarded to Victorian Fisheries, Aquaculture Section prior to fish being brought into Victoria.
• The CVO may, in proportion to the perceived risk, impose additional requirements on a case-by-case basis.

Translocation of eels within Victoria

This protocol addresses the following translocation activities:

• importing shortfin glass eels collected from Victorian waters;
• importing longfin glass eels collected from Victorian waters; and
• importing shortfin restock from wild eel fishery in Victoria.

Translocation restrictions outside natural range

• Eels for the purposes of aquaculture will only be transported to authorised aquaculture licence holders endorsed for eels.
• Eels must only be transported in containers as described in the section entitled "Approved transport containers."
• Water used to transport eels must be obtained from a municipal, bore or rainwater supply or treated according to the water treatment requirements described in AQUAVETPLAN.
• Water used to transport eels into Victoria must not be discharged into any water body, including streams, lakes, dams, drains and wetlands, within Victoria.
• The destination facility be an approved culture facility as described in the section entitled "Accredited aquaculture establishment."
• Dead or moribund eels must not be disposed of in any water body.
• Records of all translocations of eels outside the natural range must be kept by the receiver and distributor for a period of three years and copies forwarded to Fisheries Victoria on request. Records must include the source, destination and quantity of eels translocated and dates such translocations took place.

Translocation restrictions within natural range

• Eels for the purposes of aquaculture or stock enhancement must only be transported to authorised aquaculture licence holder endorsed for eels.
• Eels must only be transported in containers as described in the section entitled "Approved transport containers."
• Water used to transport eels between catchments must be obtained from a municipal, bore or rainwater supply or treated according to the water treatment requirements described in AQUAVETPLAN.
• Water used to transport eels into Victoria must not be discharged into any water body, including streams, lakes, dams, drains and wetlands, within Victoria.
• Dead or moribund eels must not be disposed of in any water body.
• Records of all translocations of eels within the natural range must be kept by the receiver and distributor for a period of three years and copies forwarded to Fisheries Victoria on request. Records must include the source, destination and quantity of eels translocated and dates such translocations took place. Where translocations are for the purpose of eel stock enhancement under an Aquaculture (Crown land) Licence, records must be maintained in accordance with the requirements of catch-effort returns/logbooks.

Approved transport containers

An approved container for the transport of eels within each species' respective natural range is a:

• closed and secure aerated or oxygenated tank;
• plastic bag, secured in a manner so as to minimise the risk of escape of eels, that contains water and air/oxygen and is closed, sealed and placed within a plastic or polystyrene box (double plastic bag in cardboard box); or
• secure mesh bag within closed or semi-closed container.

An approved container for the transport of eels outside each species' respective natural range is a:

• closed and secure aerated or oxygenated tank; or
• plastic bag, secured in a manner so as to minimise the risk of escape of eels, that contains water and air/oxygen and is closed, sealed and placed within a plastic or polystyrene box (double plastic bag in cardboard box).

Accredited aquaculture establishment

Requirements for an aquaculture establishment to become accredited to hold eels from outside their natural range are discussed in Appendix 4. In summary, the facility must:

• be a closed recirculating aquaculture facility;
• not discharge water to a natural water body; and
• have negligible risk of eels escaping.

In addition to the above:

• facility staff will maintain a formal diary of fish health and observations including daily mortality and incidences of significant stress that result in mortality;
• as a part of the fish health accreditation process, a veterinarian will review this diary;
• the facility will preserve in ten percent formalin representative samples of any moribund fish from the rearing tank that will be the source of eels for the proposed consignment; and
• the preserved samples will be made available to an approved veterinarian for the purposes of the health accreditation process.

Animal welfare

This protocol represents industry's commitment to best-practice farming and handling of eels. It applies in all circumstances.

The ability of eels to cope with the stress of transport will depend on the state of health, species, age, sex, stocking density, period without food, the duration of the trip, the mode of transport and water quality.

During transport, stress can be minimized by:

• providing oxygenation, or aeration as a minimum;
• limiting exposure to extremes or rapid variation in environmental conditions including temperature, water quality, noise, visual disturbance (light) and vibration;
• preventing unnecessary handling;
• appropriate administration of an approved anaesthetic/sedative prior to handling;
• regularly inspecting and monitoring (every two to four hours) conditions in the transport vessels; and
• adding salt (5 to10 g/l) to the transport water to reduce osmoregulatory dysfunction.

Acknowledgements

This report was written by Lachlan J. McKinnon. The author wishes to thank the members of the risk assessment panel for their assistance in producing this protocol and the members of the Translocation Evaluation Panel and the Fisheries Co-Management Council Victoria.

References

Anon (1998). Victorian Aquaculture Strategy. Fisheries Victoria. Department of Natural Resources and Environment.Anon (2003).Guidelines for assessing translocations of live aquatic organisms in Victoria

. Department of Environment and Primary Industries, Victoria.

Anon (2003b) International Aquatic Animal Health Code, Office International des Epizooties, Paris.Australian/New Zealand Standard for Risk Management (AS/NZS 4360:1995). Standards Australia/Standards New Zealand.

Gosper, D (1996). A Guide to the Diseases and Parasites Occurring in Eels. Aquaculture Source Book Publication, Turtle Press Pty Ltd.

Herfort, A. and Rawlin, G (1999). Australian Aquatic Animal Disease Identification Field Guide. Agriculture, Fisheries and Forestry: Canberra. 91 pp.

Appendix 1: Definitions

Accredited Aquaculture Establishment: A holding/nursery facility meeting prescribed criteria to supply juvenile eels to growers in Victorian.

Approved Laboratory: A laboratory, approved by a Competent Authority (see below), that conducts diagnostic work on diseases listed by the World Organisation for Animal Health (OIE) and which is responsible for health control work.

Biosecure Aquaculture Facility: See Appendix 4.

Catadromous: The migratory behaviour whereby eels spend most of their lives in fresh water, but travel to the sea in order to breed there.

Closed system: An aquaculture system in which control over the movements of organisms and/or water exists can be exerted.

Competent Authority: The National Veterinary Services, or other Authority of a Member Country, having the responsibility and competence for ensuring or supervising the implementation of the aquatic animal health measures recommended in the Aquatic Animal Health Code (Anon 2003b).

Consequence: The outcomes of an event or situation expressed qualitatively or quantitatively, being a loss, injury, disadvantage or gain.

Disease: Clinical or non-clinical infection with one or more of the aetiological agents of the diseases listed in the Aquatic Animal Health Code (Anon 2003b).

Endemic Species: Species restricted in distribution to a particular region.

Exotic Species: Species present in a particular region but which is not native to that region.

Feral Species: Non-endemic, or exotic organism that successfully establish as a result of escape or release.

Likelihood: Probability or frequency of a particular event or situation occurring.

Notifiable Disease: A diseases whose presence must be reported to veterinary authority of the region in which it is identified.

Open system: A system where no, or inadequate, control over the movement of organisms and/or water exists.

Population: A group of organisms of the same species inhabiting an area.

Quarantine: Maintaining a group of aquatic animals in isolation with no direct or indirect contact with other aquatic animals, in order to undergo observation for a specified length of time and, if appropriate, testing and treatment, including proper treatment of the effluent waters.

Risk: The chance of undesirable events, expressed as a function of the likelihood and consequence of such events.

Risk Assessment: The process of determining the likelihood and consequence of an event in the context of existing risk control measures. Estimates of likelihood and consequence are combined to arrive at a given level of risk.

Semi-closed system: A system where control over the movement of organisms, and some control over the movement of water, exists.

Stock enhancement: Increasing the populations of eels in individual water bodies by stocking juvenile eels from other sources.

Appendix 2: Risk assessment study of eel translocation in Victoria

Translocation Activity 1: Shortfin "restock" from wild eel fishery in Victoria taken under Access Licences

Translocation Activity 2: Shortfin elvers imported from Tasmania

Translocation Activity 3A: Shortfin glass eels collected from Victorian waters and translocated within natural range

NB: Risk Assessment for Translocation Activity 3A is equivalent to the Risk Assessment for Translocation Activity 1, so not repeated here.

Translocation Activity 3B: Shortfin glass eels collected from Victorian waters and translocated outside natural range

Translocation Activity 4: Shortfin elvers from intensive aquaculture facility (single species only)

Translocation Activity 5: Longfin glass eels collected from Victorian waters

Translocation Activity 6: Glass eels of both species from interstate

Appendix 3: Eel holding/ nursery establishment fish health accreditation form

Particulars:

Company: ____________________________________________________

Location: _____________________________________________________________

Company delegate (on behalf of owner): __________________________________

Authorised fish health veterinarian: _____________________________________

Inspection date: ____ / ____ / ____; Time inspection commenced: ______ Time inspection ended: ______

Results for each rearing tank from which consignment(s) will be taken:

Declaration:

I________________________________________ being the facility owner / manager or their agent, hereby state that the verbal and written information provided to the authorised fish health Veterinarian shown below is both true and correct.

Signed: ________________________________________________________________ Owner / Manager / Agent.

I ________________________________________ being the approved fish health Veterinarian on behalf of Victorian Fisheries, have inspected the above described facility/fish, proposed for translocation to Victoria, for notifiable diseases of finfish as prescribed in Schedule 16, Fisheries Regulations 1998, Fisheries Act 1995 and recommend the following action:

Approved for translocation Yes / No (Please circle)

Additional attached report: Yes / No (Please circle)

Signed: __________________________________________ Authorised Fish Health Veterinarian.

Appendix 4: Biosecurity of closed-recirculation aquaculture systems for species outside their natural range

Protection of ecosystems surrounding fish production facilities containing non-native species is vital to the native flora and fauna of an area. Risks to the environment include escape and establishment of a non-native species into a naive environment with consequent destruction of native species and disruption of their habitats.

Facilities that are farming fish must be able to contain these animals within a secure environment. This Appendix outlines requirements to ensure the biosecurity of such a facility.

Site selection criteria and design layout will be assessed on a case-by-case basis against the following criteria:

• The proposed site must be located at least 500 metres from permanent or intermittent natural waterways or irrigation canals.
• The grow-out facility shall be housed in a fully enclosed vermin-proof building with a concrete floor.
• The proposed site must be above the 1 in 100 year flood level.
• A bund wall of sufficient height to hold the total volume of water under culture shall be constructed within the fully enclosed facility to prevent accidental release of water into a waterway.

The following conditions relate to the management of the facility:

• Hatchery production will not be permitted within the facility.
• All discharged waters must be disinfected according to OIE recommendations (Anon, 2003b) before release to the environment.
• Any live fish leaving the farm site must do so in containers labelled with the aquaculture licence holder's name and the address of the fish farm.
• All mortalities should be disposed of in a manner approved by the Environmental Protection Authority (EPA). This may include the use of a pit covered with hydrated lime and sufficient earth to prevent access by birds. Alternatively, mortalities can be destroyed in an incinerator.
• A minimum of two site inspections shall be conducted each year by a suitably qualified person approved by Fisheries, DEPI. Inspections will assess the operator's compliance with permit conditions and a report shall be submitted to Fisheries Victoria for consideration following each inspection. The cost of inspections shall be born by the permit holder.

OIE general recommendations on disinfection

Disinfection is employed as a common disease management tool in aquaculture and should be part of a disinfection program designed for a specific purpose. Disinfection may be used in biosecurity programs to eradicate or exclude specific diseases from aquaculture establishments as well as a routine sanitary measure to reduce disease incidence within aquaculture establishments.

Disinfection of installations, equipment and transport units should be carried out using procedures that prevent the contamination of other water and other aquatic animal populations with infectious material. There are a great variety of products and procedures for washing and disinfecting installations or equipment used in aquaculture establishments or for treating effluents and wastes from quarantine and processing plants (Table 2). The decision on which product to use should take into account their microbiocidal efficacy, their safety for and the environment.

The manufacturer's instructions for effective use of a disinfectant under aquaculture conditions should be followed. Disinfectants to be used in aquaculture should be evaluated/tested against relevant aquatic pathogens under relevant conditions. Approved procedures for the use of disinfectants in aquaculture should be established.

The efficacy of disinfection is affected by various factors including temperature, pH, and the presence of organic matter. At high temperatures, the disinfecting action is faster as long as decomposition of the disinfectant does not occur. At low temperatures the biocidal efficacy of most disinfectants decreases. Many disinfectants have an optimum pH range/level, and product choice should depend on the pH of the diluent (water). For example, quaternary ammonia is more efficient at alkaline pH while iodine and iodophores are more efficient at neutral or acid pH. The presence of organic material and greasy substances may significantly reduce the efficacy of a disinfectant. Therefore, surfaces should be cleaned thoroughly before applying disinfectants. The use of disinfectants may require measures to protect personnel, and the environment. The manufacturer's instructions for safe use and disposal should be followed.

OIE recommendations for transport

General arrangements

These arrangements should be compulsory in all countries either by legislative or regulatory texts and methods of application should be described in a manual available to all concerned.

• Vehicles (or containers) used for the transport of aquatic animals shall be designed, constructed and fitted in such a way as to withstand the weight of the aquatic animals and water and to ensure their safety and welfare during transportation. Vehicles shall be thoroughly cleansed and disinfected before use according to the guidelines given in the Aquatic Code.
• Vehicles (or containers) in which aquatic animals are confined during transport by sea or by air shall be secured to maintain optimal conditions for the aquatic animals during transport, and to allow easy access by the attendant.

Particular arrangements for containers

• The construction of containers intended for transportation of aquatic animals shall be such that the release of water and animals is prevented during transport.
• In the case of the transportation of aquatic animals, provision shall be made to enable preliminary observation of the contents of containers.
• Containers in transit in which there are aquatic animal products shall not be opened unless the Competent Authorities of the transit country consider it necessary. If this is the case, containers shall be subject to precautions taken to avoid any risk of contamination.
• Containers shall be loaded only with one kind of product or, at least, with products not susceptible to contamination by one another.
• It rests with each country to decide on the facilities it requires for the transport and importation of aquatic animals and aquatic animal products in containers.

Disinfection and other sanitary measures

• Disinfection and all zoo-sanitary work should be carried out in order to:
• • avoid all unjustified inconvenience and to prevent damage or injury to the health of people and ;
  • avoid damage to the structure of the vehicle or its appliances; and
  • prevent, as far as possible, any damage to aquatic animal products, fish eggs, mollusc and crustacean larvae.
• On request, the Competent Authority shall issue the transporters with a certificate indicating the measures that have been applied to all vehicles, the parts of the vehicle that have been treated, the methods used and the reasons that led to the application of the measures.
• In the case of aircraft, the certificate may be replaced, on request, by an entry in the General Declaration of the aircraft.
• Likewise, the Competent Authority shall issue on request:
• • a certificate showing the date of arrival and departure of the ; and
  • a certificate to the shipper or exporter, the consignee and transporter or their representatives, indicating the measures applied.

Treatment of transportation water

During transportation of , the transporter should not be permitted to evacuate and replace the water in the transport tanks except on specifically designated sites in the national territory. The waste and rinsing water should not be emptied into a drainage system that is directly connected to an aquatic environment where are present. The water from the tanks should therefore either be disinfected by a recognised process (for example, 50 mg iodine or chlorine/litre for one hour), or sprayed over land that does not drain into waters containing.

Discharge of infected material

The Competent Authority shall take all practical measures to prevent the discharge of any infective material into internal or territorial waters.

Table 2 : Some approved OIE methods of disinfection.

Appendix 5. Diseases of eels

Fish diseases notifiable to the OIE

• Epizootic haematopoietic necrosis
• Infectious haematopoietic necrosis
• Oncorhynchus masou virus disease
• Spring viraemia of carp
• Viral haemorrhagic septicaemia

Of these, only epizootic haematopoietic necrosis is known to occur in inland south-eastern Australia. It is not known to infect or be carried by eels (Herfort and Rawlin 1999). Of Australia's National List of Reportable Diseases, only epizootic ulcerative syndrome (EUS or Red Spot Disease) is known to affect eels (Herfortand Rawlin 1999).

Other diseases of importance

From Gosper (1996), other diseases of importance in eels in Victoria include:

Bacterial

• Aeromoniasis (Red Fin Disease)
• Edwardseillosis (Swollen Intestine Disease)
• Gill Rot and Tail Rot diseases
• Myxobacterial Gill Disease
• Vibriosis

Fungal

• Saprolegniasis

Protozoan

• Myxidium Dermatitis
• Trichodina
• White Spot Disease

Metazoan

• Gyrodactylus infection
• Anguillicola infection
• Anchor Worm Disease