FISH FARMING TECHNOLOGY
The H2020 IMPAQT project Increasing production and sustainability through integrated multi-trophic aquaculture (IMTA) by Frank Kane, marine biologist, Aquaculture Section, Marine Institute, Ireland
Integrated multi-trophic aquaculture (IMTA) is a relatively new concept in modern aquaculture, but it has been widely practised for centuries, particularly in Asia. One of the oldest examples is rice and fish farming, where rice fields provide the environment and habitat for fish and other aquatic animals.
The principle is that the fish provide the nutrient inputs to benefit the plants and other species. IMTA is a more recent concept in Europe and the western world, where aquaculture has mirrored traditional agriculture focusing on mono-culture farming practises. The poly-culture of IMTA combines the cultivation of species from two or more different trophic levels based on their complementary ecosystem functions. For example, fed fish species with particulate organic nutrient-extractive shellfish, and dissolved inorganic nutrient-extractive seaweed or plants. Current aquaculture practises are generally a linear model, where the waste from the fish is released into the environment. In a more circular IMTA system, the waste from the fed species serves as nutrients to feed other species. What was previously considered waste, is now a useful ‘co-product’ which can be used as fertiliser, food resource, and energy by other species. The additional crops produced provide extra marketable biomass, facilitates economic diversification, enables bio-remediation of nitrification, increases environmental sustainability, increases societal acceptability, and allows more optimal use of space, all in a more efficient and responsible food production system.
Increasing production with IMTA
With more demands on marine space, room for aquaculture becomes more limited. IMTA can facilitate increased production by increasing the overall biomass produced from the same space, along with providing a diversity of product. The bio-remediation element could allow increased fish production balanced with the reduction in inputs to the environment. The bioremediation value of IMTA is one of the most relevant and valuable contributions it can make, improving sustainability and the environmental credentials of the industry, and to facilitate the eco-intensification of aquaculture. The key environmental benefits are waste remediation on a local level and efficiency in resource utilisation on a broader scale, both improving coastal ecosystem quality. IMTA also facilitates an ecosystem based approach to aquaculture management, allowing the regulation of nutrients on an area or bay level.
Developing an intelligent management platform
To understand the farming environment and be informed on the interaction between the various species it is critical to have effective and real-time monitoring, supplying reliable information.
40 | June 2021 - Fish Farming Technology