Pacific Oyster Mortality Syndrome (POMS)

Pacific Oyster Mortality Syndrome (POMS) affects Pacific oysters (Crassostrea gigas) and is caused by a virus called OsHV-1 micro variant.

It causes rapid death and high mortality rates in farmed Pacific oysters – up to 100% within days of being detected. POMS can spread quickly if introduced.

POMS outbreaks in Australia

The first Australian case of POMS was recorded in 2010 in New South Wales.

The most recent outbreak in commercially grown oysters was detected in Tasmania in 2016. Read more about the Tasmanian POMS outbreak.

South Australian POMS outbreak

In late February 2018, the first detection of POMS in South Australia occurred in feral oysters in the Port River. The virus is now endemic in the Port River, with ongoing detection throughout 2018 and 2019. The most recent detection was in January 2020.

All commercial oyster growing areas in SA remain free of disease. Efforts are focused on future-proofing the industry (e.g. bio-secure hatcheries, POMS resistant oyster breeding program) and containing POMS to the Port River area.

Read more about the Port River POMS outbreak.

POMS does not affect human health

There are no human health concerns associated with POMS, nor are there any food safety issues.

SA produces some of the finest Pacific oysters on the market and table oysters purchased from retailers, restaurants and fish processors are safe to eat.

Protect South Australia's oyster industry

The public can play a vital role in protecting South Australia’s oyster industry and the regional businesses and employment that depend on it.

If you are travelling into or through SA, you can help our oyster farming areas to remain free of disease by following these steps:

  • Adhere to the ban on removing bivalve shellfish from the Port River system, from West Lakes to Port Gawler, including Section Bank. Bivalve shellfish such as oysters, mussels, cockles and razorfish should not be taken from the Port River area for any purpose, including bait or berley. See closure information.
  • Regardless of the point of purchase, check the origin of any oysters you are carrying.
  • Dispose of any Tasmanian-sourced live oysters into landfill or at quarantine stations across SA.
  • Never discard or store live oysters in any SA waters. It is an offence under the Fisheries Management Act 2007 to release or deposit exotic and/or farmed aquaculture species (such as Pacific oysters) into the waters of South Australia – fines may apply.
  • Do not use Pacific oysters, dead or alive, as bait or berley.
  • Never use seafood sold for human consumption (including imported seafood) as bait or berley.
  • Boat owners should refer to the guidelines for good vessel cleaning practices.

As part of our efforts against fruit fly and other pests and diseases, PIRSA's Biosecurity SA officers inspect vehicles for fruit, vegetables, plants, plant related products, and oysters. The quarantine stations are located at:

  • Yamba
  • Oodla Wirra
  • Pinnaroo
  • Ceduna.

More information is available in the Ban on bringing live oysters from Tasmania into SA fact sheet. (PDF 457.9 KB)

Advice for oyster farmers: restrictions on importing

Since POMS was first detected in Australia, restrictions on importing oysters into SA have prevented disease introduction and safeguarded our oyster growing industry. These restrictions apply to several aquaculture species.

A total ban on moving live Pacific oysters (including spat) originating from Tasmania, into South Australia, is also in place. Please make sure you regularly check this website for updates. View the current livestock movement restrictions notice in relation to Pacific Oysters – South Australian Government Gazette, 19 March 2020, p. 574 (PDF).

More information is available for moving aquatic organisms.

Detecting and reporting the disease

Oyster farmers must report unexplained oyster mortality of greater than 10% at grading, particularly during warmer months with water temperatures above 17 degrees.

Take the following steps to report the disease to PIRSA:

  1. Collect at least 40 live oysters from the mortality site.
  2. Collect another 40 samples from another batch where there are no unusual mortalities occurring, if possible.
  3. Calculate the percentage of oysters that have died.
  4. Bag, label, and place fresh samples on ice. Do not freeze.
  5. Courier samples to lab within 24 hours of collecting them.
  6. Report to the Department of Primary Industries and Regions (PIRSA) using the contact details below.
  7. Report to your Bay Representative or the South Australian Oyster Growers Association.
  8. Decontaminate personnel and equipment per the See POMS decontamination advice (PDF 115.7 KB).

Further information is available in the Pacific Oyster Mortality Syndrome factsheet (PDF 208.0 KB).

POMS is a notifiable disease and must be reported immediately.

Report suspected exotic species

Early detection is important to stop the establishment and spread of aquatic pests. If you see an unusual freshwater or marine creature, report it immediately.

24 hours a day, 7 days a week

Fishwatch hotline: 1800 065 522 SA Fishing app
Page last reviewed: 13 Sep 2023

 


Top of page