SCRC: PhD : Protecting the Safety and Quality of Australian Oysters using Predictive Models Integrated with ‘Intelligent’ Cold Chain Technologies
Molluscan shellfish are high-valued seafood products that require careful supply chain management to guarantee both product safety and quality. Together, storage time and temperature exert the greatest influence on microbial food safety and quality, and must be controlled during oyster processing, transport and storage. Vibrio species are a natural component of marine and estuarine environments, unlike faecal bacteria which are typically introduced into growing waters by land run-off. Consequently, it is prudent to assume that all live shellfish may potentially contain naturally-occurring Vibrio spp. These risks, including the quality of oysters, can be controlled by proper cold chain management. Improper cold chain handling may increase risk, decrease quality and ultimately affect value and the brand. The negative consequences can easily be spread across the entire industry. Thus, a proactive strategy is required to control and predict risk, with added benefits for maintaining product quality. This can be achieved through validated tools (models) that allow all stakeholders in the cold chain to monitor how conditions influence the safety and quality of oysters. The impact will include 1) improved product safety, 2) an optimised cold chain, 3) higher product quality, 4) greater access to export markets and 5) a more cooperative regulatory environment.
Final report
Vibrio parahaemolyticus is a bacterial species indigenous to marine environments and can accumulate in oysters. Some V. parahaemolyticus strains are pathogenic and seafoodborne outbreaks are observed worldwide. This pathogen can reach infectious levels in oysters if post-harvest temperatures are not properly controlled. The aim of this thesis was to support oyster supply chain management by developing predictive microbiological tools to improve the safety and quality of oysters in the market. A predictive model was produced by injecting Pacific oysters (Crassostrea gigas) harvested in Tasmania with a cocktail of pathogenic and non-pathogenic V. parahaemolyticus strains, and measuring population changes over time at static storage temperatures from 4 to 30ºC. In parallel, the total viable bacteria count (TVC) model was measured.
The V. parahaemolyticus and TVC growth models were then evaluated with Pacific and Sydney Rock oysters (Saccostrea glomerata) harvested in New South Wales containing natural populations of V. parahaemolyticus. The model was developed into a software tool and evaluated in five different simulated oyster supply chains. Due to high uncertainty and variability associated with oyster supply chains a stochastic model which encompassed the operations from oyster farm to the consumer was built using ModelRisk® risk analysis software. The stochastic model may help the oyster industry evaluate the performance of oyster cold chains, and potentially enable real-time decisions if coupled with suitable traceability systems. It can also provide risk managers with valuable information about V. parahaemolyticus exposure levels..
Finally, in order to better understand microbial changes in oysters during distribution and storage, the dynamics of microbial communities in Pacific oysters was determined using 16S rRNA-based terminal restriction length polymorphism and clone library analyses. Significant differences in bacterial community composition were observed and the predominant bacteria were identified for fresh and stored oysters at different temperatures and storage temperature control and spoilage indicator organisms were identified..
SCRC: PhD : Methodologies for the implementation of Micro Mobile Information Systems in the Cold Chain and the resulting implications of Time Temperature logging for Models of Microbial Growth
This project fits squarely into two of the key strategies of the seafood CRC’s theme 2,
Strategy 1 - Traceability and product sensor technologies and,
Strategy 2 – Predicting and managing seafood shelf life
This project intends to work with CRC Participant seafood supply chains and key markets, however identifying which participant is still an ongoing task. Though initial contact has been made with the Tasmanian Abalone industry and the local research community the Sydney Fish market has also been visited (in an unannounced visit) for possible inclusion in this project.
The application is needed to enable better supply chain management of product quality and quality, by being able to identify products remotely (i.e. without the need for and problems of bar codes, scanners etc.) recognise potential quality problems (due to time and temperature), during product distribution, to assess the potential magnitude of those problems and to react to them in a timely manner to correct the problem or minimise its impact.
Towards reliable hatchery-produced quality blue mussels: an integrated approach to optimising supply
Tasmania in 2005/06 was the largest producer of mussels in Australia; 31% of production and 42% of dollar value. This represents a three-fold increase in production and value of mussels in Tasmania over the past three years. Further to this, Spring Bay Seafoods is Australia largest mussel producer and processor; with consider capital investment into mussel production and processing. This project will directly address the issues of high and unpredictable mortality rates of blue mussel seed during the early nursery phase. There is a need in the hatcheries to develop techniques and approaches that maximise production of quality mussel seed, through informed decisions about how physical and biological conditions in the hatchery affect the health and growth of spat.
World-wide, mussel aquaculture ventures are largely supported by collection of wild juveniles. Several commercial shellfish hatcheries, in USA and Australia, produce small numbers of juvenile mussels to supplement wild collections. Until recently the demand and value of mussels has been too poor to warrant large scale hatchery production, and most shellfish hatcheries focus on higher value species, or species for which wild collection of juveniles is not possible, eg introduced oysters. Collection of spat from the wild imposes critical limits to the capacity of the mussel aquaculture industry to increase production and to control product quality and timing of supply to markets. Reliance on wild spat leaves the industry vulnerable to recruitment failure and restricts production to seasonal availability. In recent years there has been insufficient wild spat settlement to meet the demands of the expanding Tasmanian aquaculture mussel industry. The only way that the mussel industry can begin to compete against imported products and allow Australian consumers access to Australian product is through reliable hatchery production of quality-assured spat.
Final report
SCRC: PhD 5.08 Development of vision and first feeding behaviour of Southern Bluefin Tuna and Yellowtail Kingfish larvae (Dr Jenny Cobcroft: Student Polyanna Hilder)
Australian marine finfish farming has a target to increase production to 100,000 t by 2015 (Hone, 2008). In order to achieve this ambitious target considerable growth in the quantity and quality of hatchery produced fry is vital. This project adds critical mass to the highly skilled and specialised area of larval rearing research which will under pin industry growth.
Relevance to industry priorities and Seafood CRC milestones
Developing a sustainable, aquaculture-based supply of SBT juveniles is critical for the growth of the SBT industry in Australia. By increasing our knowledge of SBT and YTK biology, informed modifications to production systems will increase larval survival, addressing four specific outputs of the Finfish - Aquaculture Production Innovation theme including; Strategy 2: 1)Reliable production of SBT juveniles, and 2) Reliable, cost-effective production of high quality juveniles of YTK & other key species, and Strategy 3: 1) Established production techniques for propagated SBT, and 2) Improved feeds and feed management for marine fish during hatchery, nursery and grow-out stages (including during sub-optimal temperatures conditions). The CRC Milestones contributed to are 1.1.2 and 1.1.3 Key researchable constraints (in SBT and YTK larval culture) identified, characterised and successfully addressed.
SCRC: PhD: understanding quality in abalone
Further understanding is required around the definition of abalone quality and how to measure it, compared to products such as salmon and red meats. The development of a rapid and cheap method for detecting taste/texture factors is necessary, and will be investigated in the project. Other future research needs on how the environment and/or diet can influence these quality factors and whether they can be manipulated to alter taste, for example, will benefit the industry in producing a more consistent product. The importance of the factors that affect quality vary according to the specific end-product to be marketed as well as the target market and consumer group, so a better understanding of market needs should be addressed.
A review conducted for the Abalone Council Australia Ltd. (McKinna et al. 2005) found that the key element identified as a barrier for Australia to break through the price ceiling was a lack of rigid quality and product integrity standards. This report highlights a number of product integrity issues for all forms of abalone including inconsistency in product quality, and identified that the abalone industry “needs a uniform grading and product quality scheme”.
This project will examine factors affecting quality of wild-harvest and cultured abalone up to the point of harvest, and also the post-mortem biochemistry and harvesting and processing effects, particularly freezing and thawing.
The project falls within Program 2, “Product Quality and Integrity” of the Seafood CRC. The end-user of the research will be industry members through the respective ACA (CRC Company member) and AAGA (CRC Supporting Participant). As the project will be examining some generic technologies and methods for quality assessment, this may have some positive applications for other projects within Program 2.
Aquafin CRC - Atlantic Salmon Aquaculture Subprogram: development of selective enrichment culture-polymerase chain reaction (SEC-PCR) for the detection of bacterial pathogens in covertly infected farmed salmonid fish
SESSF Industry Development Subprogram: alternative fuels for fishing vessels
With most of Australia's fish stocks at fully fished or overfished status, there is reduced opportunity for increasing economic returns from larger catches or unexploited resources. As a result, the fishing industry is looking for opportunities to increase its profit margins by reducing the cost of fishing. Generally, fuel is the one single highest operating cost to fishing vessels, accounting for up to 50% of the operating costs of a fishing vessel in Australia.
The Australian (and New Zealand) Fishing Industry requires assistance in becoming a more efficient user of energy. Some forms of fishing, such as trawling, expend more fuel per kg of fish landed compared to passive methods such as longlining and trap fishing. In all cases however, rising fuel prices impinge on the profitability of the operations, and ultimately put their viability in jeopardy; this has reach a critical situation for many operators in Australia.
The R&D plans and strategies of all advisory bodies to the FRDC contain high priority goals to achieve FRDC’s Industry Development goal (planned outcome):, The commercial sector of the Australian fishing industry is profitable, internationally competitive and socially resilient. This investigation into alternative fuels for the fishing industry, some of which also achieve lower greenhouse gas emissions, has the intention of improving the economic viability of fishing enterprises and shifting the industry towards a more secure position with respect to future fuel needs.