A substantial rise in future demand for seafood is forecast with ocean fishery productivity projected to decline by up to 50% in some fisheries due to ecological disruptions. A key challenge therefore will be maintaining fishery productivity. Shark Bay and the Abrolhos Islands scallop fisheries are prime examples - following the extreme marine heat wave of 2011 lost income from these fisheries is estimated at $53 million GVP, or $155 million including multipliers.

The integration of aquaculture and wild fisheries is becoming increasingly recognised as a tool for enhancing fishery productivity (Taylor et al, 2017). Re-stocking and stock enhancement following recruitment failure could lead to faster fishery recoveries, and also be used to supplement natural recruitment to provide a more consistent and higher yield harvest from year to year. Development of supply chains for scallops into domestic and overseas high-value live markets requires consistent supply. Due to climatic variability and highly variable natural recruitment there is an urgent need to investigate scallop stock enhancement using hatchery-produced juveniles in WA.

A key element for success will be the development of reliable, efficient and scalable seed production systems, which will be based on previous research findings integrated novel, contemporary shellfish production technology. During this project, 16 million cultured scallop spat are planned to be released. The annual yield of scallops from the Rottnest SWF Zone A is 25 to 50 tonnes (whole scallop weight), or approximately 250,000 - 500,000 scallops assuming an average weight of 0.100 kg/whole scallop. This Project aims to release on average 8 million spat each year of the Project (600,000, 1,500,000 and 6,000,000 of 10mm, 5mm and 2mm spat respectively), which could contribute 45,000 hatchery-produced scallops to the catch each year assuming 2.50%, 1.00% and 0.25% of 10mm, 5mm and 2mm spat released respectively were captured, increasing yield by 8.3 – 16.6 % in the annual production, demonstrating the feasibility of scallop stock enhancement.

There is a strong need to improve the Queensland scallop stock assessment. This will be achieved by undertaking a fishery-independent survey of the stock and by deriving improved mortality rate estimates (F and M) used in the quantitative stock modelling.

There is a strong need to better understand the relationship between abundance of 0+ and 1+ year old scallops and benthic habitat type. Classifying the scallop fishing grounds into habitat categories which receive varying levels of fishing effort will improve the precision of fishing mortality (F) estimates, as well as provide some understanding of possible impacts on the stock from the Gladstone Harbour dredge spoil ground. This will be achieved by obtaining measures of bottom hardness and sediment composition, and relating them to scallop abundance.

As most of the scallop fishery is located in waters of the GBRMP, which is a World Heritage Area, there is an obligation to ensure that biodiversity and ecosystem services within the Park are maintained. The project will address these needs by improving stock assessment advice on the scallop fishery.

Finally, there is a need to maintain the Wildlife Trade Operation approval which is required to export saucer scallops internationally. The project will help address the terms and conditions pertaining to sustainability of fishing the stock required by the Commonwealth Department of Environment and Energy to secure this approval.