GAIN is designed to support the ecological intensification of aquaculture in the European Union (EU) and the European Economic Area (EEA), with the dual objectives of increasing production and competitiveness of the industry, while ensuring sustainability and compliance with EU regulations on food safety and environment. Eco-intensification of European aquaculture is a transdisciplinary challenge that requires the integration of scientific and technical innovations, new policies and economic instruments, as well as the mitigation of social constraints. Successful eco-intensification of aquaculture will provide more and better aquatic products, more jobs, and improve trade balance by reducing imports. GAIN, besides looking at innovative ways of integrating cultured species, will seek integration with other sectors, in order to promote the implementation of the principles of circular economy in Aquaculture. The GAIN Consortium includes a wide range of complementary expertise and a well blended mix of research institutes and industrial partners, which will ensure the achievement of the following specific objectives: (i) Develop and optimize sustainable feeds, without increasing the pressure on land and fish stocks; (ii) Add value to cultivation, by means of innovative processes, which turn both by-products and side-streams into valuable secondary materials, thus increasing profits and minimizing the environmental footprint; (ii) Improve the management of finfish and shellfish farms, in terms of FCR, fish welfare and reduction of wastes, through the use of sensors, biomarkers, Big Data, IoT (Internet of Things) and predictive mathematical models; (iv) Support integrated policies and address current barriers to the implementation of the principles of circular economy in aquatic production.