Question Time

Algal Bloom

The Hon. N.J. CENTOFANTI (Leader of the Opposition) (14:19): I seek leave to make a brief explanation before addressing a question to the Minister for Primary Industries regarding oyster movement in the midst of an algal bloom.

Leave granted.

The Hon. N.J. CENTOFANTI: The opposition understands that there has been a recent decision by PIRSA's biosecurity division to approve a relay request for the movement of oysters from Franklin Harbour to Haslam from a fishery that has been closed under the South Australian Shellfish Quality Assurance Program to an area that is unaffected by the algal bloom. We understand approximately 20 tonnes of oysters are involved in the move from Cowell into a non-algal affected zone on the West Coast. My questions to the minister are:

1. Has there been approval for a relay request from Franklin Harbour to the West Coast?

2. If so, what are the conditions?

3. Who authorised that relay request?

4. What scientific evidence was used to approve that request?

The Hon. C.M. SCRIVEN (Minister for Primary Industries and Regional Development, Minister for Forest Industries) (14:20): I thank the honourable member for her question. As we know, brevetoxins were first detected in May 2025 through routine South Australian Shellfish Quality Assurance Program (SASQAP) testing at a concentration of 0.56 milligrams per kilogram, which is 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, weekly brevetoxin testing and monitoring has triggered the closing and reopening of several harvesting areas for oysters, pipis 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 the brevetoxin is not breached.

Closures of harvest areas prohibit the sale and movement of bivalve molluscs from those areas, and consistent with the biotoxin management plan, a harvest area is closed until the brevetoxin level falls below the FSANZ level of 0.8 milligrams per kilogram for two consecutive weeks and the Karenia species count is decreasing.

The movement of oyster stock between harvest areas is critical to many oyster farming standard operations to maximise their growth potential. The movement of oysters from a closed harvest area to another harvest area requires authorisation under the regulations, which has historically occurred in the past for closures due to other algae species or high rainfall and E.coli, with a relay request process in place.

PIRSA received applications to relay Pacific oysters from Franklin Harbour, which is currently closed due to brevetoxins. The initial request received has been assessed and the request to relay stock was authorised. The approved authorisations require all relayed oysters to remain in a quarantined area separate to existing oysters for a potential period of 60 days, with the reduction of brevetoxin to food safety level before any harvest can occur.

PIRSA will assess compliance with authorised relay through food safety audits. PIRSA continues to monitor biotoxin levels for impacted classified harvesting areas through the SASQAP. Predetermined considerations have been developed nationally, and the SASQAP relay protocols ensure compliance with the Australian Shellfish Quality Assurance Program (ASQAP) operations manual, the ASQAP Export Standards 2004.

PIRSA has undertaken a detailed risk assessment framework to evaluate against food safety and biosecurity criteria. A risk assessment completed by PIRSA considered both food safety risks along with consideration of potentially inadvertently spreading the algal bloom from a biosecurity risk perspective from closed harvest areas to open harvest areas that have not been impacted by the bloom. The assessment 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 bloom spread are low.

I am aware several oyster operators and some fisheries have raised concern of oyster relocation and possible potential to inadvertently spread the algal bloom. While I understand there are varying positions on support for oyster relays within the industry, SAOGA (South Australian Oyster Growers Association) advised PIRSA in August 2025 that the group was unable to come to a unanimous position and PIRSA should progress a process of relay.

In addition to the PIRSA risk assessment, PIRSA has actively engaged with SAOGA over recent months. SAOGA commissioned an independent risk assessment which drew on expert advice from algal bloom experts and oyster aquaculture regulators from the US, New Zealand, Tasmania and New South Wales and assessed the risk of transference of Karenia species to generate bloom to be low to moderate. PIRSA has provided oyster growers in closed areas with several options to maintain the health and quality of their oysters, including:

supporting growers to spread out oysters and/or adding additional infrastructure to their existing sites;

working with industry representatives within harvesting areas to identify underutilised space within licensed sites into which stock can be moved; and

supporting the granting of an emergency lease and corresponding licence either inside or outside of an aquaculture zone.

We will continue to work with the oyster industry and continue to support impacted oyster growers.