I
Dr Thierry Chopin Why is Integrated Multi-Trophic Aquaculture (IMTA) developing more easily, and at a larger scale, in China than in the western world?
n both Asian countries (particularly in China) and western world countries, there is a renewed interest in the development of what we now call Integrated Multi-Trophic Aquaculture or IMTA. The approaches are completely different, resulting in very different speeds of adoption and implementation of the practice; however, the differences are maybe not an extreme case of apples and oranges, and there is great merit in analysing their differences and convergences to develop what should become the efficient and responsible food, and co-product, production systems of the future.
The western world FIS and the Asian SIF approaches
7) all the above led to farmers increasing their income. Because of these advantages, demonstrated over centuries, there is strong government support at all levels for the practice, and practical policies have been put in place. Moreover, over time many variations appeared: rice-fish-crab, rice-fish-duck, rice-shrimp, etc. Land-farmers in China are not given a restrictive license to grow only certain species, but can decide and retain the combination of crops that works for them. It, then, appeared logical to apply the same approach to aqua-farmers, who respond relatively rapidly to market demands and evolving prices and returns. Something that generally strikes westerners eating at a restaurant in Asia is the highly diversified offering of seafood and the number of species, the many colours of many varieties, and the many ways of preparing all these succulent dishes. This is certainly part of the Asian culture; however, it is only possible if there is a reservoir of biodiversity in the number of species being cultivated (and fished). The government becomes involved in basic and applied research into new cultivation systems and new species. Scientists have developed projects, supported and approved by the authorities, and have been engaged in teaching farmers new techniques and protocols, and how to operate the different systems in different parts of China. As fishery resources have declined all along the coast, fishers are looking into switching their activities from capture fisheries to aquaculture and are being trained. Increasing productivity in agriculture and aquaculture, and maximising the short-term economic output of a fixed water surface, are the main driving forces in China. However, people are now realising the ecological costs and the need for remediation of deteriorating waters. The Chinese government, academics, industry, and people are looking for sustainable development solutions and IMTA is advocated as one. Interestingly, there are efforts to educate the general public and disseminate the message broadly. For example, in Qingdao, both the museum of the Institute of Oceanology of the Chinese Academy of Sciences (IOCAS), and the entrance of the Yellow Sea Fisheries Research Institute (YSFRI) of the Chinese Academy of Fishery Sciences, have displays of IMTA models within obvious plans for integrated coastal area management (ICAM). The company XunShan Group Co, Ltd, one of the biggest Chinese seaweed and IMTA companies, has converted part of its factory in Rongcheng, in Shandong Province, into a very interesting museum
Several western world research groups working on IMTA have spent the last two-to-three decades developing small-scale, mostly pre-commercial, IMTA operations, by modifying relatively small fish sites to co-cultivate invertebrates and seaweeds. Modern fish aquaculture (F) developed in the 1970-80’s, and invertebrate and seaweed aquacultures (I and S) were added in the 2000’s. This is what we can call the FIS approach (70-80’s/00’s/00’s). Commercial scaling-up has not been easy: while the biological and environmental advantages of this practice are generally accepted, adoption barriers have been mostly economic and regulatory. Asian countries have a long tradition of using different types of IMTA, long before this acronym was created in 2004. The approach in modifying their sites has been diametrically opposed: seaweed sites have Figure 1: Display at the “ocean ranching” museum of the company XunShan Group Co, Ltd, showing the diversity of organisms that can be used in an IMTA system. seen the development of smaller invertebrate, and later fish, infrastructures (the SIF approach; 50’s/80’s/90’s). IMTA operations are now covering vast dedicated areas.
A historical background favourable to the development of IMTA in China
There is a long tradition of operating freshwater IMTA systems in China. Rice-fish systems have existed for more than 1,200 years and covered 3.3 million hectares in 2000. The benefits are at several levels: 1) full use of limited agricultural land; 2) fish nutrients are available to rice; 3) fish eat rice pests; 4) there are reduced fungal infections; 5) farming the sea is generally more lucrative than farming land (no irrigation, in particular); 6) there is an increased diversification of agricultural products; and 18 | December 2018 - International Aquafeed