IMTA SYSTEMS: COMMERCIALLY & ENVIRONMENTALLY SUSTAINABLE SOLUTIONS
By Tarelaks & Moreforsking, WP1, SEAFOODTOMORROW partners
Within SEAFOODTOMORROW, IMTAs are being used in conjunction with the salmon fish feed trial experiments in WP1.
SEAFOODTOMORROW IMTAs under investigation include a salmon aquaculture cage with a field of macroalgae, like a ‘marine wall’ of seaweed, grown on ropes, in close proximity to the cages. In this system, the organic nitrogen and phosphorous produced by the fish are recycled back into the macroalgae biomass.
The seaweed, in this case sugar kelp, was seeded on ropes in autumn 2017 and the seedlings were controlled regularly during the months of growth that followed. Water quality and hydrodynamics were continuously monitored by sensors on sampling buoys. In May 2018, the seaweed was harvested, and it is currently being used to study chemical/biochemical composition and to optimise the harvesting and processing methods (e.g. drying for use in fish feed). The macroalgae produced can be recycled into the fish feed for aquaculture or be used by the food or pharmaceutical industries.
Aquaculture production using integrated multitrophic aquaculture systems (IMTA) are mutually beneficial to the fish and to ecosystem health. This synergistic approach, while reducing the overall release of residues from marine farms, provides enough byproducts to sustain the system, creating a stable balance.