Pacific Oyster Mortality Syndrome (POMS)

POMS background

Pacific Oyster Mortality Syndrome (POMS) was first seen in Australia in NSW in 2010. Since then movement restrictions have been in place on oysters and oyster products to reduce the risk of spread to other areas.

The POMS virus was first detected in Tasmania when it caused a high level of mortalities at an oyster lease in late January 2016, however tests on stored frozen oysters indicated that the virus has been present in the State since at least mid-December 2015.

Since the detection in late January 2016, Biosecurity Tasmania and the Tasmanian oyster industry have worked together to manage the effects of this disease on the Tasmanian oyster industry. Whilst the disease is a concern for oyster producers, healthy oysters can still be harvested and product being sold through retail outlets remains safe to eat.

The initial response to POMS in Tasmania included restrictions on the movement of oysters onto oyster farms while a structured testing program was undertaken to determine where the virus was present in the State. This testing program made it possible to assess oyster movements that could occur between farms without spreading the virus.

Based on the information from the POMS testing program three (3) areas of differing disease risk have been determined as a basis for issuing Movement Permits. These areas are:

POMS free area across the north of Tasmania;
Intermediate risk areas where there is little or no evidence of disease, but a risk of introduction of the disease; and
Infected areas where POMS is known to occur.

The current list of bays within the three (3) areas of differing disease risk can be found under Area Classification below.

Oyster movements and movements of oyster growing equipment off leases are allowed to occur in accordance with the conditions of a Group Permit issued by the Chief Veterinary Officer under the Biosecurity Act 2019. Such movements can occur both within areas of the same risk and into another area where there is a higher risk of POMS being present. Movements are not allowed from an area of high risk to an area with a lower level of risk of POMS being present.

Changes to the Movement Permitting System are further explained below.

Experience in other countries and other states indicates that the major cause of rapid spread of the POMS virus is by movement of oysters between oyster farms. The movement controls still in place are designed to reduce the risk of this type of spread of the virus.

As the virus is now established in Tasmania there is the possibility of natural spread to other areas, however, controlling movement of oysters will slow the overall spread of the virus and allow the industry to continue long term strategies to manage this disease.

Options for long term management include work already being undertaken by the industry to develop strains of oysters resistant to the disease.

It is important to note that oysters harvested for human consumption that are not going to be placed on another oyster farm can be moved without a permit.

POMS does not affect human health and oysters on the market are safe to eat.

Area Classification

Area classifications are designated according to the level of risk that the POMS virus is present in a bay and may change from time to time. The different areas that determine the basis for issuing a Movement Permit are:

POMS free area across the north of Tasmania,
Intermediate risk areas where there is little or no evidence of disease, but a risk of introduction of the disease; and
Infected areas where POMS is known to occur.

The current list of three (3) areas of differing disease risk is:

POMS Free areas

This is all areas of Tasmania north of a line through Launceston.

Sea Elephant Bay (King Island)
Montagu
Duck Bay
Big Bay
Port Sorell

Intermediate areas

This is the Huon-Channel area, Norfolk Bay and Great Oyster Bay.

Great Oyster Bay
Great Swanport
King George Sound
Eaglehawk Bay
Garfish Bay
Little Norfolk Bay
Port Arthur
Fleurtys Point
Great Bay
Long Bay Reef
Little Taylors Bay
Cloudy Bay Lagoon
Port Esperance
Hastings Bay
Recherche Bay
Dunalley Bay

Infected areas

Little Swanport
Spring Bay
Boomer (Blackman) Bay
Pitt Water (including Island Inlet)
Pipe Clay Lagoon
Port Cygnet (including Gardners Bay and Deep Bay)
Moulting Bay (Georges Bay)

Oyster movements, and movements of oyster growing equipment, are allowed under a Group Permit issued by the Chief Veterinary Officer, both within a risk area and into another area where there is a higher risk of POMS presence. Movements are not allowed from an area of high risk to an area with a lower level of risk of POMS being present.

Changes to the Movement Permit System

Oyster producers are no longer required to apply for an individual movement permit to move oysters and oyster growing equipment between growing regions of the State as long as the movement is conducted in accordance with the conditions set out in the Group Permit:

Group Permit Oyster Movements 13 February 2024 (PDF 157Kb)

This update to the permitting system reduces administrative burden for industry (and government), by not having to make an application each time a movement is required. The Group Permit system maintains the same level of protection offered by the previous permitting system by continuing to restrict where movements of oysters and oyster products may occur within Tasmania.

All movements of oysters and oyster products originating from hatcheries and nurseries, including oyster spat and the seed of an oyster, continue to be managed under the conditions of an Individual Permit issued by the Chief Veterinary Officer. This permit application process has not changed and is explained further below.

Note: there is normally a five (5) working day maximum turnaround on permits, but they are usually issued well within this period, however this is dependent on demand.

POMS detected in new and previously affected areas

February 2016: POMS was confirmed in Gardners Bay near Cygnet. As a result the area of Port Cygnet, which includes Gardners Bay and Deep Bay, was declared an infected area. The POMS virus was not detected in any other Channel area that season.

There have not been any further detections of POMS outside previously confirmed sites.

While the disease is a concern for oyster producers, POMS does not affect people. Oysters available on the commercial market are safe to eat.

Since detection in 2016, Biosecurity Tasmania and the Tasmanian oyster industry have been working together to manage the effects of this disease.

The development of POMS is temperature dependent, meaning that while there may be no evidence of the disease over winter, it could reappear in summer with affected areas likely to experience mortalities.

To protect the Tasmanian oyster industry, a statewide Control Area declaration is in place restricting the movement of oysters, animal materials and conveyances used in the production of oysters.

Movements of live oysters or oyster equipment throughout Tasmania is now managed under the conditions of a Group Permit issued by the Chief Veterinary Officer.

All movements of oysters and oyster products originating from hatcheries continues to be managed through the issue of Individual Permits via a formal application process – see Movement Permit Applications (above).

POMS - Control Area Declaration

9 February 2016: A Control Area was declared for the whole of Tasmania under the now repealed Animal Health Act 1995 restricting the movement of oysters and animal materials and conveyances used in the production of oysters. With the introduction of the Biosecurity Act 2019, the Control Area continues to be recognised as a Control Zone under section 177 of the Biosecurity Act 2019.