Current Research Projects - Fish (Aquaculture)
Biotechnology & epidemiology to control nodavirus in barramundi aquaculture
Optimisation of PCR tests for diagnosis of gourami viruses
Susceptibility of untested basin fish species to EHN virus and epidemiology of EHN virus in the wild
Biotechnology and epidemiology to control nodavirus in barramundi aquaculture (ARC)
Farm Animal & Veterinary Public Health Staff
Professor Richard Whittington
National Collaborators
- Mr Glenn Schipp, Darwin Aquaculture Centre
- Ms Lorna Melville and Dr John Humphrey, Berrimah Veterinary Laboratory
PhD Student
- Mr Paul Hick
Summary
Production of farmed barramundi has increased by more than 1200% in the Northern Territory since 2001 but is threatened by nodavirus infection.
To achieve growth targets for barramundi aquaculture in northern Australia the University of Sydney and the three industry partners will collaborate to:
- Control nodavirus infection.
- Develop new technologies to detect nodavirus using immunoassay and surface enhanced laser desorption ionisation mass spectrometry (SELDI)
- Develop an integrated disease control strategy based on epidemiological survey data, and ensure that it is practical and able to be widely adopted.
Control of nodavirus infection is required also to meet the national goal to boost aquaculture production to $2.5 billion by 2010. This project meets two designated national research priorities: frontier technologies for building and transforming Australian industries and protecting Australia from invasive diseases and pests. It will develop biotechnological and epidemiological tools to control nodavirus, improve biosecurity of finfish in the wild and on farms in Northern Territory, Queensland, Victoria, New South Wales, South Australia and underpin growth of the barramundi aquaculture industry in regional areas. The benefit will be increased employment and investment with economic and social returns. This project has support from all States and Territories.
Source of Funding
Australian Research Council Linkage Grant
Project Timeframe
January 2006 - December 2009
Aquatic Animal Health Subprogram: Optimisation of PCR tests for diagnosis of megalocytivirus (gourami iridovirus) and cyprinid herpesvirus 2 (goldfish herpesvirus) FRDC 2007/007
Farm Animal & Veterinary Public Health Staff
Professor Richard Whittington
Dr Joy Becker
Dr Michelle Dennis
Mr Matthew Landos
National Collaborators
Dr Brian Jones, Fisheries Department Western Australia
Dr Mark Crane, CSIRO
Summary
This project was developed in order to meet a gap in diagnostic capability in Australia for the megalocytivirus group of iridoviruses and cyprinid herpesviruses. Megalocytiviruses cause killing diseases that have devastated aquaculture enterprises particularly in Asia. Cyprinid herpesviruses are also significant, the focus of this project is CHV-2, which infects goldfish and may not be present in Australia. The urgency to do this work was highlighted by a megalocytivirus disease outbreak in Murray cod in Victoria in 2003, and by the discovery in 2004 that imported ornamental fish harboured the viruses that killed Murray cod. In addition there is a need for a targeted surveillance program to determine whether CyHV-2 is present in both domestic goldfish breeding populations and imported goldfish.
The importation of several species of gouramis into Australia in the ornamental fish trade is associated with a high risk of introduction of viruses in the Megalocytivirus genus (Family iridovirae), specifically Gorami iridovirus (GIV). Valid tests for these viruses do not yet exist in Australia. Rapid assays to distinguish these viruses from internationally notifiable agents such as Red Sea Bream Iridovirus (RSIV) are not available either, so there are risks to international trade through inaccurate diagnosis of GIV.
Goldfish are the most popular ornamental fish species in Australia. There has been a viable domestic production industry for more than 50 years. This production has supplied wholesalers, and in the case of many smaller operators, supplied direct to retail shops or the public through markets. In the last 10 years imported goldfish numbers have continue to grow, in part, due to their competitive price. The imported goldfish have been subjected to the AQIS requirements for import certification and a 3 week holding period before release. In the past 6 – 7 years anecdotal evidence suggests mortality rates of domestically produced goldfish increase when these fish are mixed in retail shops with imported goldfish. This scenario has been described and followed up with histological and electron microscopy examinations in NSW and WA. These investigations have revealed pathology consistent with CyHV-2. It has been suggested that the imported goldfish are carrying latent CyHV-2 infections and that domestic breeding stock in closed facilities remain free from this disease agent hence naïve and highly susceptible when exposed.
This project aims to provide the diagnostic capability and a sampling regime to further investigate these concerns. Specific objectives include:
- To optimise PCR for detection of megalocytivirus
- To optimise a PCR for detection of CyHV-2 in goldfish
- To transfer technology to diagnostic laboratories in Australia
Each of the aquatic animal health diagnostic laboratories in Australia have expressed a need for diagnostic capacity. End-users indicating need for the project data include regulatory agencies (AQIS, Biosecurity Australia), governmental diagnostic laboratories in the States and aquatic animal health network.
Source of Funding
Fisheries Research & Development Corporation
Project Timeframe
October 2007 - September 2008
Susceptibility of previously untested Basin fish species to EHN Virus, and the epidemiology of EHN Virus in the wild MD743
Farm Animal & Veterinary Public Health Staff
Professor Richard Whittington
Dr Joy Becker
Mrs Alison Tweedie
Mrs Rebecca Maurer
Mr Craig Kristo
Mr Jesse McIvor
PhD Student
Ms Anneke Rimmer
National Collaborators
Dr Dean Gilligan & Mr Martin Asmus
NSW Department of Primary Industries,
Narrandera Fisheries Centre
Summary
Epizootic Haematopoietic Necrosis Virus (EHNV) is a serious threat to a number of native fish species in the Murray-Darling Basin. This virus, unique to Australia, was first isolated in 1985 in Redfin perch. It is characterised by sudden high mortalities of fish. On autopsy, the fish display necrosis of the renal haematopoietic tissue, liver, spleen and pancreas. Experimental work demonstrated that a number of native species were susceptible to the disease, including the threatened Macquarie perch and Silver perch, as well as mountain galaxias. The virus has been recorded from Victoria, NSW and the ACT. The spread of EHNV has been aided by its relative resistance. It can be readily transmitted from one location to another on nets, fishing lines, boats and other equipment. It was found that the virus retains it infectivity after being stored dry for 113 days. Once ENHV has entered a water body it is considered impossible to eradicate.
Objectives:
- to validate earlier findings of susceptibility of native fish to EHNV
- to determine the susceptibility of infection by EHNV of a range of previously untested fish species in the Murray-Darling Basin
- to investigate the epidemiology of EHNV in wild populations of priority fish species
- to develop a test to determine exposure of wild populations of priority fish species to EHNV
- to identify the extent to which EHNV is a risk to native fish in the MDB
Anticipated outcomes:
- improved knowledge of the susceptibility of fish in the Basin to EHNV
- improved capacity for management of EHNV in the Basin
- improved management of redfin perch in the Basin
- improved human capacity for aquatic health issues in the Basin
Source of Funding
Murray Darling Basin Authority
Project Timeframe
November 2006 - February 2010