- Author Samantha J. Nowland & Brien H. Roberts
- Publish date 4 July 2023
- Aquaculture
Summary
The blacklip rock oyster, Saccostrea lineage J, has the potential to support new aquaculture developments throughout its range in the tropical Indo-Pacific region, but lack of research investment in understanding basic biology has been a key failure point in the past. This study assessed Saccostrea lineage J spat growth and survival in downweller and upweller nursery systems, with the aim of establishing baseline biological information and evaluating spat performance to support commercialisation efforts. Downweller and upweller nursery systems were similarly effective at rearing spat, with mean dorsoventral measurement in both systems reaching a 5 mm deployment size at 59 days post hatch. Growth rates reported in this study of 0.19 and 0.20 mm day−1 in the downweller and upweller, respectively, are comparable to other hatchery-produced tropical and subtropical bivalve spat. Based on the results of this study, it is recommended that spat be held in nurseries for approximately two months to reach a 5 mm deployment size. The information obtained in this study is the first documentation of Saccostrea lineage J spat growth and survival, and the methods used provide a basis for commercial production of this species.
**The Version of Scholarly Record of this Article is published in Molluscan Research 2023 and is available online at: https://www.tandfonline.com/doi/full/10.1080/13235818.2023.2217677
To cite this article: Samantha J. Nowland & Brien H. Roberts (2023) Assessment of blacklip rock oyster, Saccostrea lineage J, spat growth and survival in recirculating upweller and downweller nursery systems, Molluscan Research, 43:2, 101-108, DOI: 10.1080/13235818.2023.2217677
Projects
Northern Territory Tropical Rock Oyster research and development
This project established a collaborative, cross-jurisdictional approach to address the most significant technical and regulatory challenges facing northern Australia’s fledgling Tropical Rock Oyster (TRO) industry. The project was delivered by research teams in Western Australia (A.2.1819053WA) and the Northern Territory and comprised three sub-projects, each targeting specific research needs: Sub-Project 1 – Species Identification, Pathogen Screening and Translocation Risk assessment (NT) This research standardised oyster common names and assessed the need for designated farming and translocation zones across northern Australia. It considered risks associated with genetic pollution of wild populations, existing knowledge of tropical ecosystems and oyster diseases, insights from the pearl industry, and current practices in edible oyster aquaculture in other regions of Australia. The findings provided a strong scientific base for biosecurity planning, management and operational procedures for the developing industry, while also and identifying key issues for further research and development. Sub-Project 2 – Securing commercial spat (juvenile) supply Early hatchery development work in the Northern Territory and Western Australia revealed that Tropical Rock Oysters have different larval requirements compared to the commercially produced Sydney Rock Oyster (SRO) and Pacific Oyster (PO). As a result, existing hatchery manuals for SRO and PO were found to be ineffective for TRO spat production. Researchers utilised the Darwin Aquaculture Centre’s hatchery infrastructure and expertise to refine culture techniques for the Blacklip Rock Oyster. Hatchery trials focused on improving larval settlement procedures, including experiments on salinity levels, settlement timing, and the effectiveness of chemical and substrate cues. Additional work included conditioning broodstock and evaluating optimal hatchery systems. Sub-Project 3 – Optimisation of grow-out methods and gear technology This sub-project investigated optimal grow-out methods and gear technologies for Blacklip Rock Oyster production. Farming trials were conducted using intertidal systems at two sites: South Goulburn Island (supported by the Yagbani Aboriginal Corporation) and Groote Eylandt (supported by the Anindilyakwa Land Council). The trials included: Trial 1 Assessed the impact of three basket heights in the tidal range (standard, low and dynamic) and two stocking densities (standard and half of standard) on oyster growth, survival and basket biofouling. Data collected included growth rates, shell shape, survival and biofouling. Trial 2 Compared the performance of different gear types in producing marketable Blacklip Rock Oysters. This trial provided data on oyster growth and shape, as well as qualitative insights into the operation, maintenance, and performance of each system.