Development of a sustainable scallop (Ylistrum balloti) fisheries enhancement program for Western Australia: Preliminary Feasibility Study
One Sea Pty Ltd
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.
1. Develop and validate genetic tools to determine parentage / origin of scallops and measure genetic diversity
2. Develop hatchery and nursery protocols for consistent production of scallop spat
3. Develop strategies and methodologies for scallop spat deployment and stock enhancement sampling; measurement of seeded scallop spat survivorship; assessment of effect of spat size at deployment on survival rates; duration of growth to market size; determine impact of enhancement