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Legislative Council - Fifty-Fifth Parliament, First Session (55-1)
2025-11-27 Daily Xml
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Algal Bloom

The Hon. N.J. CENTOFANTI (Leader of the Opposition) (14:43): Standing, Mr President.

The PRESIDENT: There we go.

The Hon. N.J. CENTOFANTI: I seek leave to make a brief explanation prior to addressing a question to the Minister for Primary Industries regarding oysters.

Leave granted.

The Hon. N.J. CENTOFANTI: Different oyster growing areas of our state continue to have the sale or movement of oysters prohibited from their waters with the ongoing presence of both Karenia algae and associated brevetoxin. The opposition continues to hear concerns from algal growers in unaffected waters that there may be consideration from PIRSA of applications for the translocation of oysters from waters affected by Karenia algae to their unaffected areas. My questions to the Minister for Primary Industries are:

1. What is the safe level of Karenia algae within water where oysters are moving from to ensure there is no risk to the waters where oysters are being moved to?

2. What peer reviewed scientific data about Karenia algae within oysters has been taken into consideration on the basis of any decision about whether to approve a translocation?

3. Are there any restrictions on oyster movements beyond the levels of brevetoxin, which are solely based on food standards only rather than any risk associated with Karenia algal movement?

The Hon. C.M. SCRIVEN (Minister for Primary Industries and Regional Development, Minister for Forest Industries) (14:45): I thank the honourable member for her question. She did refer to algal growers. I think she meant oyster growers, so I will take it as though the question was about oyster growers.

Members interjecting:

The PRESIDENT: How about you sit quietly, in that corner?

The Hon. C.M. SCRIVEN: The issue, obviously, for our oyster growers is significant. A number of areas have been closed for some months. Of course, there are a number of other areas that have been able to continue to trade uninhibited, because, of course, they have not had the algal bloom, nor have they had brevetoxins recorded within the oyster meat.

It is particularly important that the reputation of our oyster industry is protected. Obviously, food safety standards always come first, but it is incumbent on all of us, I would suggest, to ensure that international markets in particular but other markets also are aware that the issues for the oyster industry are limited to a small number, notwithstanding, of course, that for those who are directly affected it is incredibly significant. That was one of the reasons I had a meeting with oyster growers in Cowell just last week to discuss, first of all, the impact that they are experiencing from all of these matters but also to get feedback on the support that has been provided through the state and federal governments.

Brevetoxins were first detected in May of this year through routine South Australian Shellfish Quality Assurance Program (SASQAP) testing at a concentration that was below the Food Standards Australia New Zealand (FSANZ) regulatory limit of 0.8 milligrams per kilogram. Notably, brevetoxins had not been detected in Australia previously. Since May 2025, weekly brevetoxin testing and monitoring has triggered the closing and reopening of some harvesting areas for oysters, pippies and mussels in line with the Primary Produce (Food Safety Schemes) (Seafood) Regulations 2017.

This is to maintain food safety standards and ensure the Food Standards Australia New Zealand regulatory limit of 0.8 milligrams per kilogram for brevetoxin is not breached. The opening and closing of harvest areas is not dependent on the amount of Karenia species detected but the level of brevetoxin contained in shellfish meat.

Closures of harvest areas prohibit the sale and movement of bivalve mollusc from those areas, and consistent with the biotoxin management plan a harvest area is closed until two consecutive weeks of results indicate that brevetoxin levels are below the FSANZ level of 0.8 milligrams per kilogram and declining or static. When a harvest area is open, producers are free to move oysters to other harvest areas.

The movement of oyster stock between harvest areas is critical to many oyster farming operations to maximise oyster growth, maintain stock quality, manage farm logistics and respond to market pressure, with specific harvest areas having environmental characteristics that support particular life stages of oyster development. Some producers have become specialised in growing a particular life stage of oysters and may sell or move oysters when they grow beyond that life stage.

The movement of oysters from a closed harvest area to another harvest area requires authorisation under the regulations. These relays have previously occurred for closures due to the presence of some harmful algae species above trigger levels or high rainfall and E.coli, with a relay request process in place to facilitate these movements.

Predetermined criteria have been developed nationally to inform relay authorisation, and SASQAP relay protocols ensure compliance with the Australian Shellfish Quality Assurance Program (ASQAP) operations manual, the ASQAP export standards 2004 and relevant state legislation.

In the anticipation of a need to facilitate the relay of shellfish from areas closed because of biotoxins, a review of national and state relay requirements was recently led by the Department of Agriculture, Fisheries and Forestry (DAFF) in consultation with state governments. That review was undertaken during 2023, and South Australia updated its relay guidelines in 2024 in response to the review.

In response to the current algal bloom, and to better understand the risk that oyster relays may play in spreading Karenia species to unaffected areas, the South Australian Oyster Growers Association (SAOGA) commissioned an independent risk assessment. PIRSA facilitated a workshop of algal bloom experts and oyster aquaculture regulators from the US, New Zealand, Tasmania and New South Wales to help inform the SAOGA risk assessment.

On 10 September, SAOGA advised PIRSA that, although they had finalised their risk assessment and had undertaken extensive consultation to form a position on oyster relays, there was not a unanimous view within the industry. To inform the management of oyster relay risk, PIRSA animal biosecurity completed a risk review drawing on the risk assessment already completed by SAOGA and concluded that both the absolute risk of spread of the algal bloom via oyster relays, as well as the relative risk these relays may play in spreading the algal bloom compared to other means of spread of the bloom, are low.

PIRSA informed oyster producers who were in attendance at the annual SAOGA seminar on 17 October that PIRSA would assess oyster relay applications on a case-by-case basis, and that the relay applications needed to meet national criteria to ensure food safety standards were met. Following the SAOGA seminar, PIRSA received applications to relay Pacific oysters from Franklin Harbour, which is currently closed due to brevetoxins, to Haslam on the West Coast. There is only one oyster producer in Haslam.

PIRSA was advised by oyster producers that similar movements of large amounts of oysters were made from Franklin Harbour to Haslam in the three weeks leading up to the closure of Franklin Harbour on 30 July 2025, when at the time Karenia species counts were above 150,000 cells per litre, higher than the Karenia detection levels at Franklin Harbour at the time of the relay request. Importantly, weekly routine testing of Haslam has not detected an increase in Karenia species as a result of these movements.

PIRSA assessed the relay applications against the criteria and risk assessment, and the request to relay stock was authorised. The approved authorisations were time-bound and took over a two-day period in October, which has now lapsed. I am advised that PIRSA currently has no active applications.

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