A key component of SafeFish is proactive research to identify and mitigate risks before they cause a problem, or to grow knowledge to improve our risk management in a cost-effective manner. For the 2022 to 2025 period, SafeFish will be facilitating technical research on the following issues that were identified as high priority for the Australian seafood sector:
Listeria monocytogenes and Ready to Eat (RTE) Seafood
A growing demand for short shelf life ready to eat (SSL-RTE) seafood products, coupled with the evolving food ecosystems and consumer interactions has placed renewed focused on the need to develop educational tools and/or a compendium of useful resources for industry and provide greater awareness of what ‘best-practice’ may look like.
Listeria monocytogenes is the only species of Listeria that is pathogenic to humans and whilst it generally does not affect healthy adults and children, listeriosis can be very serious for pregnant women and their unborn children, new-born babies, the elderly and people with a weakened immune system.
Between January 2012 and August 2022 there have been 14 recalls in Australia due to the presence or potential presence of L. monocytogenes in seafood products. Fortunately, listeriosis outbreaks associated with seafood in Australia are relatively rare. However, in 2019 two people from a vulnerable population died and another two non-fatal illness occurred that were attributed to the consumption of smoked salmon sourced from Tasmania. No recall was issued and a subsequent investigation by Biosecurity Tasmania found no breaches of regulations.
The objectives of this project are to:
- Improve food safety practices related to RTE seafood through the provision of easily accessible resources.
- Liaise with industry and regulators to determine if there is an appetite for a Listeria masterclass and if ascertain potential content and format of delivery.
- This project will run from January 2023 to July 2023.
Chemical contaminants are often widely found in the marine environment, either occurring naturally (such as arsenic, cadmium or mercury) or through anthropogenic sources (such as lead, and Agricultural/Veterinary chemicals). They have the ability to accumulate in seafood grown in areas where they are present in high concentrations. The consumption of seafood with high levels of these compounds has the potential to cause chronic human health conditions.
Due to advancing toxicological evidence on contaminants, international regulations continue to be more restrictive (reducing or tightening MRLs and MLs at Codex, in the EU and Japan). Recently we have seen recalls as a result of cadmium detection in rock lobsters exported to China and isoeugenol residues detected in eels sent to Korea. Contaminants have also caused a number of national incidents, including metal contamination from dredging in QLD, contamination of water from lead smelter operations in SA, and detection of metals in TAS heritage and commercial waters. Whilst data on contaminants in seafood is available in Australia, there is a need to collate this information and assess if it is vast enough to ensure that we have a strong knowledge base for responding to risk and potential incidents in the market.
The objectives of this project are to:
- Collate and review all available testing data on chemical contaminants in seafood (metals and Ag/Vet chemicals) to identify gaps and/or deficiencies.
- Facilitate a workshop to review the data collated and identify priority areas where additional testing would be beneficial. Design a testing program and coordinate laboratory analysis on priority contaminants and species identified from the workshop.
- This program will run from January 2023 to January 2025.
Vibrios in Seafood
Vibrio species are a naturally occurring marine bacteria, some of which are pathogenic to humans. There have been 5 recent outbreaks and >310 illnesses of Vibrio parahaemolyticus in Australia associated with oysters. The risk of Vibrio associated with seafood was identified as a critical issue in SafeFish risk register national process. There are currently no national standards for Vibrio spp. in seafood and management is based on responding to outbreaks by limiting harvest of seafood and tightening temperature controls in areas that have been associated with outbreaks.
Vibrio risk is predominantly a concern for bivalves, but in NZ over the 2021/2022 summer, illnesses were associated with lobster, abalone, urchin, and finfish species. This is a complex issue with poor knowledge on prevalence in Australian aquatic environments, pathogenicity of strains, environmental triggers of pathogenic strains, relationship between pathogenicity and illness, and difficulty in identifying pathogenicity targets for test development. These factors have together resulted in a low capability to detect pathogenicity in Australia. Compounding risk management, V. parahaemolyticus is currently not a notifiable pathogen in every Australian state and consequently illnesses are under-reported. Internationally, outbreaks are less common than sporadic illnesses and this is also true of illnesses in Australia thus far. As Vibrio risk is closely related to an increase in temperature and other environmental triggers and Vibrio are opportunistic bacteria with fast growth rates and high plasticity, this issue is likely to increase with the changing environments expected with climate change.
There are significant knowledge gaps in environmental risk and human health response to Vibrio and currently there is no uniform national policy for risk management. Cold chain management and traceability is linked to this issue and have been highlighted as areas that need improvement in the recent outbreaks. Also, a recent change to the Australian Standard method of analysis from a quantitative to a qualitative test could have impact on market access and outbreak response activities and is likely hinder the collection of additional information to inform future risk management.
There are a number of processes that are currently occurring to address the research gaps for Vibrio and SafeFish is heavily involved in a number of these. This project will focus on improving the knowledge and tools necessary to effectively manage Vibrio risk by undertaking the following objectives:
- Conduct a review of available international testing methods for vibrio detection to highlight which would be appropriate for implementation in Australia Perform a validation study on the most appropriate method determined (if not already validated)
- Determine the national volume of Vibrio testing in seafood required in Australia and liaise with Australian commercial laboratories to identify laboratories that will offer NATA certified quantitative Vibrio analysis.
- Provide technical and financial support to the national collaborative research strategy for Vibrio parahaemolyticus.
- This project will run from January 2023 to June 2025.