Yes, it is feasible, but technical, engineering and cost challenges remain. The future development of offshore or exposed ocean aquaculture will depend on the technology that is implemented to overcome the extreme conditions of the oceanic climate, the logistical problems to bring feed and other inputs to the farm, the development of offshore working platforms and the remote control of the platforms based in the internet of things (IoT) to communicate and to manage the platforms with optimisation systems based on artificial intelligence.

Integrated Multi-Trophic Aquaculture (IMTA) is a type of aquaculture where several aquatic species from different trophic levels (eg. fish, seaweed, shellfish or other invertebrates) are farmed in close proximity in the same production system to improve efficiency, reduce waste and provide ecosystem services, such as bioremediation.

The ‘Strategic guidelines for a more sustainable and competitive EU aquaculture for the period 2021 to 2030’ promote IMTA, among other types of aquacultures that are most beneficial for the environment and the climate.

IMTA can cover many different types of aquaculture systems, such as land-based aquaculture systems (e.g. ponds) and net pens systems (e.g. combination of fish farming with off-bottom and on-bottom systems for bivalve molluscs and seaweed production). However, the aim is always to increase environmental sustainability, economic stability and social acceptability, within holistic and circular economy approaches.

IMTA systems enhance aquaculture sustainability by mimicking natural nutrient cycles. In these systems, the organic matter that is not used by one species, such as fish, becomes a resource for others, like seaweed and molluscs, which use the nutrients to grow. The effectiveness of the system depends on environmental factors, such as nutrient levels in the area, food availability and hydrodynamics.

Several challenges remain in the adoption of IMTA. For example, according with the EU legislation, aquaculture animals cannot be feed on waste, which means that the legal framework in force invalidate models where fish are combined with certain filter feeders and detritivores species (low trophic species as bivalve molluscs and sea cucumbers) which recycle the nutrients from fish uneaten feed and faeces. To assess and help address these challenges the EU is funding several projects on IMTA such as Astral (https://www.astral-project.eu/ ) and AquaVitae (https://aquavitaeproject.eu/).

In 2020, EU aquaculture production reached a total of 1,2 million tonnes, with a value of EUR 3,9 billion. At that time, the main aquaculture species produced were sea mussels (19% of total EU production), rainbow trout (17%), blue mussels (11%), Pacific cupped oysters (9%), gilthead seabream (8%), Mediterranean mussels (7%), European seabass (7%), common carp (7%) and Atlantic bluefin tuna (3%). These nine species account for 87% of the total EU aquaculture production in weight (STECF 22-17-EU).

This Commission Staff Working Document covers energy efficiency and the use of renewable sources of energy to reduce the carbon footprint in primary aquaculture production. In addition to EU Member States, this document’s development has also drawn on practices and tools from the United Kingdom (UK) and Norway due to their proximity to the EU and the importance of their aquaculture production, research and innovation.