A wave of mortality has decimated (i.e. hundreds of tonnes killed) abalone stocks in NSW, and caused significant losses (i.e. >$3 million per year) to stakeholders in the fishery and unknown effects on the coastal environment. This project is a direct outcome of a National Workshop on Perkinsus, attended by government agencies, FRDC and Industry, where the need for urgent research was recognised.

It is unclear if the mortality of abalone is still spreading because of a lack of information from the fronts of mortality. Should the mortality spread further south into increasingly high density stocks of abalone, there will be a rapid escalation of impacts. The lack of information about past and current effects on abalone populations is directly compromising current management of the fishery within the affected area.

There is very little information currently available about what is killing the abalone. Sick and moribund abalone have been found to be infected by the protistian parasite, Perkinsus olseni. Despite that, it is not clear whether Perkinsus is responsible for the mortality, or whether other factors are involved.

There is a strong and urgent need for basic information about the past spread, and current pathogenesis and epidemiology of the mortality of abalone in NSW. Outcomes of the project will directly aid current management of the fishery in the effected area through information on the stock that remains and an understanding of the causes of the mortality. Ultimately, this research may also provide techniques to reduce the effects and spread of mortality that can be incorporated into future management strategies for all abalone fisheries in Australia that could be affected by Perkinsus-related mortality.

Black soldier fly farming (BSF) is an emerging industry that provides a low-cost waste management solution for converting agricultural waste into high quality fertiliser (BSF castings or frass) and protein (BSF larvae as animal feed). However, the BSF products cannot be developed further in Australia until biosecurity, environmental and food safety risks are addressed. This collaborative project between industry, government and researchers will a) develop frass as a slow-release, granulated fertilizer product that is safe to handle, transport and apply; b) quantify the biosecurity and environmental risks associated with applying frass to cropping and c) overcome the barriers to adoption by involving policy makers and farmers during trials and assisting early adopters through extension activities. Adoption of BSF technology and its products has potential to increase productivity and profitability via reduced input costs and alternative revenue streams on agricultural enterprises.

Primary industries produce large volumes of waste by-products that often contain significant amounts of macro and micro-nutrients that are typically in a dilute, nutritionally unbalanced form for agricultural crops (Abbott et al., 2018). The handling, management and application of wastes are costly and time consuming for producers whilst transportation and reuse off-farm is currently impractical and uneconomical. Poor livestock and waste management practices in the past have led to stable fly (as opposed to the Black Soldier Fly which is not a pest) outbreaks, odour, GHG emissions and nutrient leaching and runoff into waterways. This has resulted in stringent application restrictions being imposed for manure application through Health Regulations 2001 and through the Biosecurity and Agriculture Management Act 2007 (BAM Act). These regulations on manure disposal have led to loss of important marketing options causing significant cost increases (> $4 million annually). Currently, composting to Australian Standards on-site is both costly and lengthy and does not have sufficient scale, capacity or end market to process the entire allotment of manure. Consequently, large quantities of manure (225,000m3 of manure per annum) are transported long distances to broadacre agricultural zones for pasture and crop fertilisation at a significant cost to producers.
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BSF technology has potential to improve profitability and sustainability for livestock and cropping industries by significantly reducing waste volumes whilst creating a high value fertiliser product. Once fully commercialised, BSF cultivation could process hundreds of tonnes of waste per day, requiring only a small amount of space. The BSF technology is both suitable for medium to large enterprises and provides more flexibility for smaller enterprises or regional hubs. The BSF reproduces rapidly, have high feed conversion efficiency and produce half a tonne of frass for every tonne of waste processed (Moula et al., 2018). The BSF process has also been shown to significantly reduce the biosecurity and environment risks associated with waste management. The BSF larvae outcompete stable fly, decrease the nutrient content (total N by 55 and P by 45%, respectively) and lower pathogen loading of E. coli and Salmonella levels (Lui et al., 2008; Erickson et al., 2004). In addition, BSF have been shown to reduce antibiotics and antibiotic resistant genomes in waste substrates (Cai et al., 2018). Therefore, the resulting frass fertiliser has potential to mitigate and lower the risk of contamination, GHG emissions, nutrient leaching and runoff. Developing the frass as a high quality fertiliser would open new markets and create new revenues for profit, making BSF more economically viable for the livestock industries. However, the agronomic and economic value of frass fertiliser as well as the environmental and biosecurity risks of their application needs to be evaluated to increase adoption. Also, the frass fertilizer products must be tailored to crop nutrient requirements, machinery and operations. In addition, research is needed to understand the mode and mechanisms of delivery so that the frass can be developed as a slow release fertiliser to minimise the loss of nutrients through runoff, leaching and GHG emissions. Further research on the social license and regulatory

Internationally, Tropical Rock Oysters have a poor safety reputation with Vibrio at the top of the list. While a pro-active not reactive approach to vibrio food safety is essential for product assurance and branding, effort needs to be proportional to risk. And risk assessment also needs to be informed by real data. There are certainly knowledge gaps for north Australia, but we know seawater contains up to 42 Vibrio spp. including several known toxigenic species in addition to the human pathogens Vibrio parahaemolyticus (Vp) and V. vulnificus (Vv). We know Vp responds to temperature but Vv does not. And we know Vv concentrations in seawater are higher in the wet season compared to the dry, and more shellfish are Vp and Vv positive in the wet season. So if vibrio diversity and abundance in TRO is seasonal (as shown elsewhere), it is likely that Vibrio spp. infections in humans will also follow a seasonal trend which has implications for risk management. A major bottleneck is that we don’t know how vibrios respond to storage and transport temperatures in TRO. We know that the Pacific and Sydney Rocks respond differently so it is not ‘one size fits all’ and it is certain TROs will be different again. In addition to identifying vibrio baselines in TRO and developing tests for toxigenic species, we will identify the best post-harvest storage and transport temperatures and assess TRO shelf life at realistic storage temperatures. This will provide fundamental information to inform cold supply chains that will support farmers, wholesalers and retailers of TROs from north Australia. We can also use this information to prepare an appropriate and regionally relevant vibrio risk profile for TRO in northern Australia to assist initial risk management activities. This information will provide the developing TRO industry with the knowledge needed to ensure an exemplary reputation, thus giving access to premium markets.