The Sydney Rock Oyster (SRO) is iconic and has been an important protein source for thousands of years in Australia. Fast forward to 2017, the Sydney Rock aquaculture industry sells 5.5 million dozen each year and is worth $40 million farm-gate.
But the picture isn’t completely rosy. Its history has been, well, rocky. The SRO is susceptible to disease, such as QX and winter mortality. QX disease is caused by a parasite that destroys the oyster’s digestive system, resulting in starvation. Winter mortality disease affects Sydney rock oysters’ in its southern growing range and the exact cause still remains a mystery. While both diseases are not harmful to humans, they are costly to industry.
One way to address this problem has been through selective breeding to develop disease resistant oysters. NSW DPI, The Select Oyster Company along with geneticists at CSIRO have been working collaboratively together and have seen encouraging results.
One historical barrier standing in their way has been the cost of running a breeding program, which has limited them to a relatively small breeding population. This changed in 2016 thanks to funding from the Future Oysters CRC-P.
Since then, NSW DPI has been able to boost breeding effort, disease resistance and further their understanding behind the mechanisms of resistance through “Project 2016-802” (a.k.a “Accelerated SRO breeding research”).
Mike Dove has been leading the project which has had a strong industry focus. “When we were developing the concept for this project, we asked industry what their priorities were and they said we want high QX resistance, fast growth with no loss of meat condition.” In short, not rock oysters that rock out; but high-performing oysters that are stayin’ alive.
Over the past two years, the project team has accelerated genetic progress in SRO as a direct result of increasing the number of families they produce and refining their testing methods. This begs the question: What makes these oysters more resistant than just your standard oyster?
This is currently being pondered by researchers at Macquarie University (MU) in collaboration with NSW DPI. MU are specifically looking at “Marker Assisted Selection”, which identifies genes that best predict QX resistance and growth.
This can be used to better identify resistant animals in not only the breeding population but also in wild populations to fast-track breeding. It also serves as a risk management strategy to safeguard the breeding program into the future. In the unlikely event the breeding population is decimated or quarantined, this information could be used to rapidly build up a new batch of resistant oysters from the wild.
To date, the project 2016-802 has had some good wins.
They are on target to deliver what they committed to the CRC-P. For example, they have pushed their breeding program by creating more families and conducting additional experiments to test how selected oysters perform on oyster farms.
They have had mixed success with winter mortality due to the disease being elusive but have had good results with QX. Winter mortality trials are currently in progress to see if they can get further information this year.
As to what happens next, Mike and his team have their work cut out for them.
They’re going back into the hatchery in November to produce another 80 families for the breeding program which will take the total number of families in the breeding program to beyond 300. At the same time, they’ll be analysing data from all of their field trials to fine tune the breeding program to reduce costs and be more efficient for industry.
Whilst it is uncertain about what will happen after the funding runs out from the CRC-P next year, Mike feels grateful for the CRC-P: “So much has come out of this. It begs the question; how do we use this as a platform to go to the next level? We’ve been really fortunate to have the CRC-P as it will allow us to deliver to industry what they have asked for and we will be able to provide this in a shorter period of time. I think it’s important that industry can easily access the benefits of the breeding program because this is what supports future work and investment in the programs future.”
If you'd like more information on this project, please visit: https://www.oystersaustralia.org/project-2016-802
The author acknowledges that the CRC Program supports industry-led collaboration between industry, researchers and the community. The Future Oysters CRC-P, which focuses on the production of ‘Better’, ‘Healthy’ and ‘More’ oysters, is led by Australian Seafood Industry Pty Ltd in partnership with Oyster Australia Ltd, Select Oyster Company Pty Ltd, Fisheries Research and Development Corporation, Department of Primary Industries and Regions (South Australian Research & Development Institute), University of Tasmania, The Flinders University of South Australia, The University of Newcastle, The University of Adelaide, Commonwealth Scientific and Industrial Research Organisation, University of Technology Sydney, University of Sunshine Coast, Macquarie University, Department of Skills and Regional Development (NSW), and The Yield Technology Solutions Pty Ltd.