Aquaculture – sometimes called mariculture when in the sea – is the production of fish, invertebrates (e..g. bivalves) and plants (seaweeds) in aquatic systems and by a variety of production methods. Typically these different types of organisms are grown separately. Integrated Multi Trophic Aquaculture (IMTA) is a concept where different species are grown together in such a way that the invertebrates and/or plants can recycle the nutrients that are lost from the culture of the other species.
An example of this might be a fish farmer who adds fish feed to his cages of fish in the sea knowing that a proportion of the feed, all of the faeces and most of the nutrients in that feed will not end up in his fish but will be lost to the environment. However, if the farmer develops a bivalve culture operation near his fish farm, these filter-feeders might benefit by consuming some of the particles of feed and faeces and so grow faster or bigger than they might otherwise have done. Additionally the farmer might elect to grow some seaweed near his fish farm. These plants can utilise the nitrogen excreted by the fish and the bivalves to enhance their growth. The result is that there is a net reduction of losses to the environment plus new crops to harvest and sell.
Multi trophic aquaculture has been practiced for centuries in freshwater systems, particularly in China. Although the potential benefits of this system are well understood, IMTA is only practiced in the EU by a few specialist companies. The IDREEM project is dedicated to finding out why this is the case and to considering the issues and bottlenecks that may prevent development of this eco-efficient practice. We will consider social, economic and environmental issues with a view to improving our understanding of the technological and financial issues that may stand in the way of IMTA being adopted by aquaculture enterprises and also the social issues that influence consumers and the general public so that we can better understand market issues.
The project is driven by SME involvement, with a bias towards commercial partners. The results of our work will therefore primarily focus on providing routes to IMTA for enterprises in order to create new employment and growth opportunities as well as tasty and healthy seafood and other products.