Road map for prawn recovery
International experience is helping Australia’s prawn farmers rebuild from the recent white spot disease outbreak.
By Wayne Hutchinson
Photo: Gold Coast Marine Aquaculture
The detection and spread of the highly contagious white spot disease (a viral disease affecting crustaceans including prawns, lobsters and crabs) in Australia late last year has devastated prawn farmers in the Logan River region, south-eastern Queensland.
Since the confirmation of white spot disease in late 2016, the FRDC has provided support to the prawn industry by helping document the disease as it spreads and the response by government and industry, and assessing the financial cost to aquaculture and fisheries.
While the outbreak is devastating, there is a wealth of international experience with the disease that is providing guidance to help the industry recover and rebuild, while also helping to improve its defences against other disease threats. This knowledge has been used to develop a response plan, including the assistance the industry needs in order to recover.
In March, prawn farmers, government representatives, researchers and industry suppliers attended a workshop in Brisbane to hear how industries overseas have responded when confronted with white spot disease. The event was an initiative of the Australian Prawn Farmers Association (APFA) and supported by the FRDC and the Department of Agriculture and Water Resources.
Case studies from Brazil, Ecuador and Saudi Arabia were presented at the workshop. All are countries where significant outbreaks of white spot disease have occurred and where prawn farming industries subsquently recovered production to levels similar to, or greater than, pre-outbreak levels. The case studies outlined the impact of the initial outbreak and the responses used to achieve business continuity.
Marcell Boaventura from Ridley Australia described the chronology and impact of white spot disease in Brazil, where it spread along 4300 kilometres of coast over 12 years, progressively affecting Brazil’s entire industry. He highlighted the need to maintain environmental controls and to commit to biosecure procedures, particularly when production systems have been intensified as a means to recover production.
Francois Brenta, an expert in prawn farming and biosecurity, has worked in Brazil, Ecuador and Saudi Arabia. He told the workshop that Ecuador’s production dropped from 114,000 tonnes in 1998 to 40,000 tonnes in 2000, following the initial disease outbreak. Production recovered during the next decade to 148,000 tonnes, which was made possible by several factors.
He highlighted the use of domesticated disease-free broodstock to supply post-larvae for farms, adoption of more rigorous biosecurity-focused management practices and support from government to reinforce disease control measures. He described a similar scenario for the disease impact and recovery in Saudi Arabia.
The message to industry from the workshop was that disease is an ongoing business risk and must be managed accordingly. White spot is only one of several serious disease threats, and the Australian industry must remain vigilant.
Detailed approaches used in other countries to manage this risk at each stage of the production chain from broodstock to on-growing systems were presented. These included the:
- filtration and disinfection of pond water to eradicate virus carriers before stocking disease-free prawn larvae;
- establishment of a disease-free and disease-resistant broodstock breeding program;
- incorporation of high biosecurity standards across all parts of the production chain;
- greatly reduced water usage to minimise risk; and
- development of culture systems and methods to create a more stable and optimal growing environment to minimise stress.
In the weeks following the workshop, Francois Brenta travelled to prawn farms in northern areas of Queensland to meet key staff, inspect production systems and discuss methods to improve biosecurity infrastructure and management approaches to reduce disease risk.
He then visited affected farmers in the Logan River region. From these visits and discussions, he is developing a report for the APFA that will provide practical recommendations to industry and government for managing the outbreak of white spot disease in Australia and a proposal for long-term solutions.
FRDC Research Code: 2016-266
Wayne Hutchinson, 0439 636 375,