Project code FRDC 2011-053

POMS was first reported in Australia in late 2010 in association with high mortality outbreaks in the George’s river and is also present in wild oysters in Sydney Harbour. POMS disease has already wiped out major oyster production farms in France and other countries. Despite some evidence suggesting that the disease may spread through boat movements and appears to be associated with increases in water temperature in summer, very little objective information is available about the major factors responsible for the outbreaks. In France, the cause seems to be multi-factorial, with interactions between the physiological status of the oysters, the environment and other pathogens.

We began intensive field work on POMS in September 2011. The aim of the project is to determine whether biotic and abiotic factors influence POMS, and whether there are simple husbandry factors that growers can change to protect their oysters from the disease.

Biotic factors are pathogens like POMS virus (OsHV-1 u-var) and Vibrio bacteria. We detect these pathogens using virology (qPCR) and microbiology culture) tests in our laboratory at Camden. We also examine oyster tissues microscopically (histopathology).

Abiotic factors are things like water temperature and salinity. We measure these intensively by placing data loggers on each oyster lease. We also utilise water quality measurements taken from probes in each estuary by the Sydney Meteropolitan Catchment Management Authority and Hornsby Shire Council.

Husbandry factors are things like the age of oysters when they are stocked or harvested, intended growth rate, height of racks, trays or baskets, and stocking density.

This new project is supported by funding from Fisheries Research and Development Corporation on behalf of the Australian government, the University of Sydney, the Sydney Metropolitan Catchment Management Authority Botany Bay Water Quality Improvement Program (BBWQIP) and Siminis Oyster Splitting Systems, with the strong support of oyster growers from the Georges and the Hawkesbury Rivers, Hornsby Shire Council, and NSW Industry and Investment.