PROJECT DESCRIPTION
BACKGROUND
According to World Bank projections, the demand for aquatic products is expected to rise to some 261 million tonnes by 2030; with 62% of the overall quantity coming from aquaculture production, which is expected to triple. However, the effects of this economic sector on the environment can be significant. The main problems concern water pollution and waste generation, which typically cannot be sent to recycling or crushing plants as aquaculture is based on cages placed underwater. As a result, in most fish farming systems, metabolic by-products, food residues, faecal matter, and residues of prophylactic and therapeutic compounds are discharged into the sea, with no prior treatment. This affects the water and sediment quality and facilitates diseases among the species reared with possible health risk for humans and marine biodiversity. Therefore, new systems able to mitigate and reduce the environmental impacts of the aquaculture sector are urgently needed, keeping in mind both market needs and EU legislation and especially the EU strategic guidelines for more sustainable and competitive aquaculture for the period 2021-2030.
OBJECTIVES
The main objective of the REMEDIA LIFE project was to develop and demonstrate the effectiveness of an Integrated Multi Trophic Aquaculture (IMTA) system as a way to mitigate the negative environmental effects of aquaculture activities. This innovative fish farming system (implemented for the first time in the Mediterranean) was based on a new set of stress-tolerant bio-remediators (polychaetes, macroalgae and sponges) to give a better bioremediation performance for the whole plant.
The new bioremediation technology was demonstrated on a pre-industrial scale at a mariculture farm in a confined environment which produced also both edible and inedible biomass suitable for biotechnological exploitation. Another aim of the project was to introduce the new IMTA system to the market in order to ensure the creation of a virtuous circle and encourage sustainable aquaculture throughout Europe. Although the project did demonstrate the possibility to produce a series of applications from the cultivated biomasses (e.g., animal feed, ornamentals species for aquariums, bioactive compounds, fishing baits…), it has encountered difficulties in scaling-up production or marketing them due to a series of policy, technical and market barriers which should be still resolved.
RESULTS
With 3 breeding cycles conducted in the mariculture farm, the project was able to harvest 2,400 kg of polychaetes, 775 litres of sponges, and 3,900 kg of macroalgae, in addition to the reared fish and mussel products. This has allowed achieving the following environmental benefits:
- Bioremediation of 70% of the seawater surrounding the pilot farm and a recovered balance of the marine environment;
- More than 50% improvement in the chemical-physical quality of the water in terms of dissolved oxygen;
- Improved trophic conditions of the marine coastal waters with a reduction in the TRIX index relating from an initial value of “moderate quality” to a value of “good quality” at the end of the project;
- 80% reduction of faecal contamination;
- Improved fish rearing performance and reduced risks associated with bacterial contamination;
- Improved fouling biodiversity on the structures of the fish cages.
In addition, the project has:
- Analysed the collected biomasses to identify accumulations of harmful substances, showing that macroalgae is the most “pollutants free” organism, which therefore can be used both for human consumption as well as to produce feed for fish species and fertilizers.
- Engaged in an effective communication campaign both among local population (including a unique teaching module in schools) and with other aquaculture plants, possible end users of the biotechnological applications, and the scientific community.
- Developed a management plan for the pilot aquaculture farm;
- Drafted guidelines to aid the replication of the project’s methods across Europe; and
- Signed 3 agreements with stakeholders to replicate and transfer the project’s results.
