New Opportunities For Abalone Processing Waste
Accelerating Greenlip Abalone stock recovery in South Australia using release of hatchery-reared juveniles: Phase 1 - genetics risk assessment and preliminary cost-benefit analysis
There are areas of the Western Zone Abalone Fishery where Greenlip Abalone are depleting, with biomass levels well below carrying capacity and historical levels. Some areas may not recover quickly without intervention and recovery may be further impeded by climate change. Thus, the Western Zone wild-catch abalone industry is seeking to establish a commercial-scale stock release program to accelerate Greenlip Abalone stock recovery in South Australia using release of hatchery-reared juveniles. The Central Zone wild-catch abalone industry is seeking to establish a commercial-scale stock release program to re-build Greenlip Abalone stocks in depleted areas that will use hatchery-reared juveniles.
There are two key needs for commencing a stock recovery program using hatchery-reared juveniles. The key industry need is to test release of juvenile Greenlip Abalone in the Western and Central Zones to evaluate the long-term economic viability. To support this important industry goal, the key Government need is for data to underpin release policy. This includes knowledge of the geographic distribution of Greenlip Abalone genetic differentiation (after Miller et al. 2014, Sandoval-Castillo et al. 2017), to inform policy review.
References:
Miller et al. 2014 – Molecular genetics to inform spatial management in benthic invertebrate fisheries: a case study using the Australian Greenlip Abalone.
Sandoval-Castillo et al. 2017 – Seascape genomics reveals adaptive divergence in a connected and commercially important mollusc, the greenlip abalone (Haliotis laevigata), along a longitudinal environmental gradient.
Project products
Indicators for density and biomass of exploitable abalone – developing and applying a new approach
The impact and implication of Perkinsus olseni on Australian abalone fisheries
Perkinus olseni is a protozoan parasite that has negative effects on three commercially harvested abalone species in Australia – blacklip, greenlip and Roe’s. Disease manifestation ranges from high mortality (e.g. New South Wales; Liggins and Upston 2010) to chronic clinical infection (Gudkovs 2016). Chronically infected animals often exhibit extensive macroscopic lesions rendering the product unsaleable. Outbreaks in the 1980s in the South Australian (SA) Central Zone (SACZ) fishery removed 15 t of greenlip catch, with partial recovery of the fishery taking 30+ years. Avoidance of fishing areas in the SA Western Zone (SA WZ) abalone fishery with high prevalence of Perkinsus-related lesions has displaced ~10% (11t.yr-1) of blacklip catch to alternative fishing grounds, exacerbated quota reductions and likely cost the fishery in excess of $10 million over the past ten years.
The impact of Perkinsus on abalone fisheries has not been fully quantified and the factors driving prevalence and disease expression are unknown. This information is fundamental for the effective management of this disease, and in particular the prevention of its spread and proliferation.
Understanding the impacts of Perkinsus on abalone fisheries and developing strategies for mitigating impacts are the highest priority research need of the SAWZ. These aims are also relevant to the Abalone Council Australia strategic plan and supported by the SACZ and SA Southern Zone abalone fisheries because of the threat this disease poses to both fisheries.
This project will consolidate current knowledge on Perkinsus, describe the impact and drivers of the disease in Australia, and determine whether shucking at sea is a high risk. This information is necessary to mitigate the spread and impact of the disease where abalone are currently shucked at sea. If shucking at sea is a high risk we will evaluate alternative ways in which harvesting can occur without further disease spread.
Australian Abalone Growers Association Strategic R&D Plan 2020-2025
Western Abalone Divers Association 2020 Quota Setting Workshop: Opportunity for shared understanding of potential TACC setting processes by Western Australian Abalone stakeholders
Risk factors and management strategies associated with summer mortality in Australian abalone
Mortality events in aquaculture require comprehensive investigation to establish aetiology. This assists with providing effective treatments (if available) and maintaining trade and market access. Good evidence of the diseases status of Australian farms is crucial in negotiating with countries we export to. This was illustrated recently when Canada stopped all Australian abalone imports and requested disease free certification for numerous diseases. In order to facilitate trade and market access, and improve the understanding of summer mortality in Australian abalone, it would be valuable to:
1. Summarise current abalone health and summer mortality research to identify key risk factors associated with summer mortality and develop industry guidelines for reporting summer mortality events
2. Develop a case definition for summer mortality
3. Summarise retrospective mortality investigations and laboratory submissions for Australian abalone
4. Investigate summer mortality events during the life of the project to comprehensively rule out primary pathogens and infectious agents in both control and impacted populations.
Final report
i. Chronic mortality of unknown cause (if in doubt take this to mean >0.15% mortality of individuals in a tank per day (tank-1 day-1) for at least one week) above the farm’s winter baseline mortality rate in >1 year old abalone, and
ii. occurs in at least two culture units, and
iii. occurs between January and April, but,
iv. excludes those diagnosed with an OIE notifiable disease as the primary cause of mortality.