The BLUEBOOST project promotes the development and validation of innovative Integrated Multi-Trophic Aquaculture (IMTA) systems as a solution to improve sustainability in the aquaculture sector. By co-cultivating species from different trophic levels such as fish, bivalves, macroalgae, and other invertebrates . IMTA systems enhance nutrient recycling, reduce environmental impacts and contribute to a more circular and climate-resilient Blue Economy.
In Italy, the Sardinian case study is coordinated by the International Marine Centre (IMC) and is located in the Gulf of Oristano, a mesotrophic coastal environment in the central-western Mediterranean. The pilot system integrates an existing commercial fish farming facility rearing species such as European sea bass (Dicentrarchus labrax), gilthead sea bream (Sparus aurata) and meagre (Argyrosomus regius) with the cultivation of the European flat oyster (Ostrea edulis), a native species of high ecological and commercial value.
As part of this IMTA system, oyster farming gears, including lantern nets and Australian baskets, have been suspended at 3 m depth in close proximity (~30 m) to the fish cages. The goal is to evaluate the growth performance of O. edulis and to study potential trophic interactions between the fish species and oysters . Water quality and stable isotope analyses have been conducted to assess nutrient flows and the ecological functioning of the integrated system. Furthermore, local hydrodynamic conditions were evaluated to elucidate water circulation patterns and associated particle dispersion dynamics, thereby enhancing the interpretation of isotopic signatures and better assess trophic connectivity within the IMTA setup.
To complement these investigations, microbiological studies were also carried out on surface sediments, with seasonal sampling. Using next-generation sequencing (NGS), the diversity and structure of benthic bacterial communities were analyzed across multiple stations influenced to different extents by the IMTA system.
In addition to field activities, a crucial component of the Sardinian IMTA system is the production of O. edulis spat at IMC’s experimental hatchery. The hatchery is equipped with dedicated units for phytoplankton cultivation, broodstock conditioning, larval rearing, settlement and nursery. IMC successfully completed the full hatchery cycle starting from locally harvested broodstock , gamete induction and fertilization, larval metamorphosis and juvenile growth , until producing over 5,000 spat that were transferred to sea for on-growing once they reached an average shell length of 18.7 mm.
This production process has also led to the drafting of a technical protocol for O. edulis seed production, with potential application in small-scale commercial aquaculture and oyster restoration initiatives. The protocol covers key aspects such as biosecurity, water quality control, feeding regimes, and grading procedures, providing a practical tool for hatcheries aiming to produce robust and healthy oyster seed.
The results of this pilot, together with those of five other case studies across Europe and South America, will feed into broader evaluations of IMTA’s environmental and economic performance using Life Cycle Assessment (LCA) and other multidisciplinary tools. Through this integrated approach, BLUEBOOST aims to facilitate the adoption of IMTA systems at commercial scale and inform future policy and investment in sustainable aquaculture practices aligned with European climate and biodiversity strategies.