Final Report 2016-266 - Prawn White Spot Disease Response Plan
The aim of this report is to provide guidance to Australian prawn farmers and governments about how to respond and recover from the impact of the outbreak of White Spot Disease (WSD) in Queensland that began in November 2016.
Principal Investigator: Dr Len Stephens
Key Words: White Spot Disease, White Spot Syndrome Disease Virus, prawn, Code of Practice, EADRA, Black Tiger Prawn, Penaeus monodon, Aquaculture, farmed prawns
The aim of this report is to provide guidance to Australian prawn farmers and governments about how to respond and recover from the impact of the outbreak of White Spot Disease (WSD) in Queensland that began in November 2016. Outside the scope of this report is a complementary response plan for fifteen commercial fishers affected by WSD being prepared by Queensland Seafood Industry Association (QSIA).
The report has been prepared by interviewing affected farmers, industry leaders, government officials, farm advisers and scientists. The literature on control of WSD in other countries has also been reviewed.
The response to the outbreak was still underway when this report was written. As such it should be seen as an interim report that may need to be updated if the situation changes.
White Spot Disease of prawns is a highly infectious disease caused by White Spot Syndrome Disease Virus (WSSV). The disease is exotic disease to Australia and is listed by the World Organisation for Animal Health (OIE – Office Internationale des Epizooties http://www.oie.int/ ), meaning that it is mandatory for Australian authorities to report incidents and respond according to pre-agreed procedures. When the disease broke out in a cluster of prawn farms bordering the Logan River, the Queensland Department of Agriculture and Fisheries (QDAF), with the support of the industry, implemented a strategy of Eradication, with the intention of following the Australian Aquatic Veterinary Emergency Plan (AQUAVETPLAN) – Disease Strategy Manual for WSD of Prawns (http://www.agriculture.gov.au/animal/aquatic/aquavetplan/white-spot ).
Consequently, six family businesses that owned seven prawn production farms and one separate hatchery within a designated control zone were quarantined, and all stocked ponds must be chlorinated, then drained and dried out.
There are 22 operational prawn farm businesses in Australia. The farms affected by WSD have lost most of the current season’s income of approximately $25million. In order to continue to farm in future years all affected and non-affected prawn farms will need to invest in significant capital improvements to strengthen their biosecurity. The size of this investment could exceed $50million. The cost to QDAF for controlling the outbreak is $4.4million to date and is certain to rise.
A key determinant of the path to recovery for affected farms is whether or not they will be able to restock their farms by September 2017. To achieve this the affected farms will need:
- Clearance from QDAF to restock based on satisfactory decontamination of their farms.
- Preparation of a Code of Practice (CoP), agreed between industry and QDAF, that stipulates the minimum biosecurity standards required for prawn farms to operate in the WSD control zone and provides guidance on the levels of water treatment, vector control and farm infrastructure improvements needed to achieve the standard.
- The CoP to be enforced through an appropriate regulatory mechanism.
- Agreement on a reduced biosecurity level in the CoP once Australia is declared WSD free.
- Certainty from QDAF that should WSD recur on farms that have restocked, those farms will be able to implement an agreed, on-farm WSD quarantine and containment strategy rather than complete destocking.
- Updating the hatchery biosecurity facilities within the control zone to provide WSSV free prawn post larvae (PLs) to stock the ponds.
- Strengthening of the application of controls on the importation of uncooked prawns and investigations to discover how WSD entered their farms.
- Urgent updating of the prawn broodstock translocation protocol to increase the level of testing for WSD. This must include fast turn-around of broodstock test results.
At the time of writing there is considerable doubt that the decontamination and disposal operations underway in the control zone will be completed in time for those farms to make the changes necessary to comply with the CoP prior to restocking in September 2017.
If farms in the control zone do not receive clearance to restock, their losses will be compounded by inability to produce a crop of prawns for another year. This will threaten the viability of the businesses. Consequently, an option is for the affected farms not to restock until next season. This would give a better biosecurity outcome but it would not be possible unless the affected farms received financial compensation.
Unaffected farms outside the control zone should also, if finances allow, implement enhancements to biosecurity to reduce the risk of WSD.
If WSD cannot be eradicated within the control zone, the strategy is likely to be changed to one of Control and Contain and individual farmers will need to determine whether they will continue to operate, based on the likelihood that biosecurity improvements can prevent WSD recurring on their farms. Key to this will be ongoing surveillance for WSD in wild prawn populations.
Reliance on the current reliance on wild caught brood stock to produce PLs for each years’ production is now an unacceptable risk for the industry. Work must begin immediately to establish a communal facility for production of Specific Pathogen Free broodstock. For the future, further research is also needed into:
- Breeding prawns for WSD resistance
- Validation of commercial diagnostic tests for WSD and other diseases by farmers and their advisers
- Proof of freedom from WSSV of current wild and domesticated stocks.
- Continued research into vaccination of prawns against diseases.
- The use of interference RNA (iRNA) to clear viruses from broodstock
- The complete range of chemicals available for control of carrier crustaceans, particularly crabs.
As with all other aquaculture and wild caught seafood industries in Australia, an Emergency Aquatic Animal Disease Response Agreement (EADRA) and associated cost sharing arrangements, are not in place between the APFA, Australian and State governments. A working group composed of government and aquaculture representatives is in place to remedy this situation but will not complete its work until the end of 2017. The APFA has contributed positively to this working group and should use the impetus of this incident to ensure it has a swift, successful outcome.
A complementary report to this one, prepared by Ridge Partners financial consultants, has examined the financial impact of this incident on the farms affected by WSD. There is strong case for the farm businesses affected by WSD to be paid compensation. Financial assistance will be necessary for the industry to recover and adapt to its new circumstances. Australian governments are therefore encouraged to consider the following funding proposals as outlined in the Ridge Partners report:
A. Establishment of an EADRA – like agreement to provide for payment of $7,883,525 to the six affected farm businesses as compensation for their direct losses.
B. Establishment of an industry adjustment fund to provide $12,653,153 to enable the six affected farm businesses to install biosecurity infrastructure needed to meet the new CoP.
C. An ex gratia payment of $11,890,540 to the six affected farm businesses if they are required to defer production until next season
D. A grant of $3 million to be administered by Fisheries Research and Development Corporation (FRDC) on behalf of APFA to establish an SPF broodstock facility and provide for the significant increase in disease testing of broodstock it will require.
It must be recognised that any cost sharing agreement between industry and government to provide this funding will be limited by the small size of the prawn farming industry. With only 22 businesses to spread costs between, the amount per business to cover the above amounts will be prohibitive.
A solution to this, consistent with the EADRA principles would be to cap the maximum repayment to be made by industry to a proportion of GVP. A levy could then be implemented whereby all prawn farm businesses repay this amount over ten years.
An alternative arrangement that would distribute the cost over many more businesses would be for the wild harvest and aquaculture sectors of the prawn industry, and the major businesses in the supply chain, to contribute a very modest levy for a defined period to repay the above amounts.