AVG remains the greatest threat to the economic viability and stability of the abalone industry in south-eastern Australia. As a consequence, there is an urgent need for strategic research aimed at determining the likely vulnerability of fisheries to future AVG outbreaks and providing managers with the necessary tools for biosecuring wild and farmed stocks at regional, state and national scales.
The fact that some animals from AVG affected wild stocks survived the disease outbreak suggests they were either fortunate enough to have avoided coming into contact with the virus or are genetically resistant to the disease. A research program aimed at characterising AVG resistance in Australian wild abalone fisheries is expected to provide benefits to wild and farm fisheries at a national scale. If AVG resistance is present in wild abalone stocks, and its genetic basis can be characterised, there will be unique opportunities to:
1) Rapidly and cost-effectively screen stocks across all wild fisheries to determine the spatial prevalence of resistant genotypes and to gain an understanding of how biosecure wild abalone stocks are likely to be in the event of AVG re-emergence
2) Biosecure wild stocks through the movement of animals from ‘AVG resistant’ to ‘AVG vulnerable’ stocks as part of future restocking and translocation activities
3) Biosecure farm stocks across all states of Australia through the establishment of an AVG resistance breeding program
This project involves a direct partnership with AAGA, ACA and VFA and is expected to provide much needed insights into the vulnerability of abalone stocks to future AVG outbreaks, and the tools needed to bolster the biosecurity of wild and farmed abalone stocks. As a result, this project has the potential to dramatically improve the economic viability of this rapidly expanding industry.
Final report
characterised, there may be opportunities to:
1) Improve industry knowledge of the mechanisms for animal persistence in virus affected Abalone fisheries and on the resilience of Abalone fisheries to environmental change;
2) Screen wild fishing stocks across all wild fisheries to determine the spatial prevalence of resistant genotypes and to help identify stocks are likely to be resilient or vulnerable to AVG reemergence;
3) Explore options for biosecuring wild stocks through the movement of AVG resistant genotypes to ‘AVG vulnerable’ stocks as part of future restocking and translocation activities; and
4) Establish AVG resistant breeding lines for biosecuring farm stocks across all states of Australia.
In this study we performed a genome wide association study on the Blacklip Abalone (Haliotis rubra) using pooled whole genome re-sequencing data from 343 H. rubra specimens representing 14 Victorian fishing stocks varying in historical AVG exposure. Analyses identified approximately 25,000 SNP loci associated with AVG exposure, many of which mapped to genes known to be involved in herpesvirus response pathways and general virus-host interactions in Haliotids and other animal systems. Most notably, candidate loci mapped to 24 genes known to be associated with Haliotid herpesvirus-1 (HaHV-1)
immunity in the New Zealand pāua (H. iris). Experimental trials are now needed to validate if, and how much, resistance is determined by the candidate genotypes identified in this study before the industry can harness them for management purposes with confidence. This study provides the first line of
evidence of genetic changes and adaptive responses in AVG affected H. rubra fisheries. These findings have potential implications for future management which are discussed in detail but will require further investigation.
