Unravelling the causes of Pacific Oyster mortality

Oyster aquaculture is worth $35-40 million to the NSW economy and is an important source of employment and revenue for coastal communities. However,  oyster aquaculture industries are globally under threat from disease outbreaks.

Oyster diseases have caused devastating losses for Australian oyster farmers, with a recent outbreak of the OSHV-1 virus causing $6 million worth of losses of Pacific Oysters in Tasmania. Pacific Oyster mortality events can be caused by a range of different pathogens, but even in cases where an implicated pathogen has been identified, they often appear to occur as a consequence of a complex and synergistic interplay between environmental conditions, pathogen abundance and virulence and oyster physiological state.

To try to unravel the causes and dynamics of Pacific Oyster mortality events, a team of researchers from the University of Technology Sydney (UTS), led by Professor Justin Seymour of the Climate Change Cluster (C3) and Associate Professor Maurizio Labbate of the School of Life Sciences, working in collaboration with the New South Wales Department of Primary Industries (NSW DPI), have established an experiment at SIMS to examine the factors responsible for Pacific Oyster mortality events. A major focus of this work, which is supported by the Future Oysters Cooperative Research Centre Project and an Australian Research Council Linkage Grant, will be elucidating the role of the oyster microbiome – the community of microbes living in and on the oyster – in oyster disease outbreaks.

In Nov 2017 UTS PhD student William King and Post-doctoral Research Associate Dr Nachshon Siboni deployed 960 Pacific Oysters at SIMS, and have since then collected oysters on a weekly basis, for the characterisation of the oyster microbiome and detection of pathogens, while also measuring a wide range of environmental parameters such as temperature, salinity and nutrients. The team plan to unite microbiological measurements, with environmental data and oyster physiological conditions using sophisticated modelling approaches, with the ultimate goal of defining the triggers of oyster mortality events.

This information will aid in the management of oyster aquaculture, by delivering a new capacity to predict the occurrence, provide early warning and decrease the impact of disease outbreaks on our aquaculture industry.

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