Prospective assessment of the aquaculture sector: National policies and environmental impacts

Today, global food production is challenged by a continuously growing world population and increasing wealth. Food demand rises drastically and constantly, and meeting this demand requires developing and improving the current food production system on a global scale. This development needs to happen in a sustainable manner to ensure that meeting the needs of the current generation does not prevent the coming generations from meeting theirs. Sustainability has three pillars, namely environmental, economic and social, but environmental sustainability is particularly important as it is a prerequisite for social and economic sustainability because society and the economy rely heavily on the well-functioning of the Earth system to thrive. In that setting, aquaculture appears like a promising solution to tackle the global nutrition challenge, as it has been associated with more environmental-friendly production than other animal protein sources and with significant growth potential. However, despite the flourishment of audacious aquaculture growth policies in recent decades, only a few countries seem to have truly benefited from a noteworthy aquaculture development (e.g. China, Norway and Brazil). The failure of these aquaculture growth policies in other countries has been associated with a lack of prospective assessments regarding environmental, social and economic sustainability, which led to insufficient anticipation of the policies implications. There is therefore a need to develop assessment tools that would quantify the sustainability of aquaculture growth policies to foresee their implications and thereby help policy-makers to refine and adapt these policies and ultimately prevent them from failure. The environmental dimension of sustainability being essential, it should be prioritized. This leads to the following research goal: “How to assess the current and prospective environmental sustainability of aquaculture growth policies?”

By answering that research goal, this PhD project contributes to filling the gap in aquaculture policy support. It produces a framework to assess the current and prospective environmental sustainability of aquaculture growth policies. The background and context of this PhD work, as described above, are presented in chapter 1 of this manuscript, leading to the introduction of the research goal and research questions in chapter 2. Life cycle assessment (LCA), an ISO-standardized methodology, is recognized by regulatory bodies such as the European Commission as an adapted tool to assess the environmental sustainability of products and systems and has already been extensively used to assess aquaculture systems. LCA was therefore selected as a relevant tool to of these studies. A discrepancy between the geographical scope of the studies retrieved and the global repartition of the aquaculture production was found, especially for the Asian continent that gathers more than 90% of the aquaculture production worldwide, to be contrasted with a representation of only 25% in the pool of LCA studies. Feed is generally found to be the most contributing life cycle stage, and several strategies have been considered to decrease its impacts such as changing diets’ composition or reducing the feed conversion ratio. The technology type and the intensity level are found to be important factors influencing the environmental impacts as well, with modern and intensive technologies being usually associated with large global impacts (e.g. climate change and energy use) while traditional and extensive technologies are usually accompanied with higher local or regional impacts (e.g. eutrophication and water use). The methodological choices of the retrieved studies are also analyzed, and improvement potentials in the application of the LCA methodology are highlighted. Overall, the relevance of LCA as a decision-making tool is confirmed, and the importance of conducting large-scale studies (at country or regional level) and prospective analysis is justified.

Chapter 4 introduces the framework developed to analyze the environmental impacts of aquaculture growth policies, and describes its four steps to allow future practitioners to apply it. Step 1 consists of an in-depth description of the seafood production in the considered country, with the identification of species groups and technology types currently in use and their categorization based similar environmental profiles. An optional step O can then be applied to perform a micro-level LCA of the production categories built in step 1. In step 2, scenarios of aquaculture development are constructed using an economic demand-supply equilibrium model to reflect different ways of implementing the assessed policy. Step 3 is a macro-level LCA to quantify the environmental impact of the scenarios developed in step 2. Finally, step 4 is the interpretation phase.

In chapter 5, the developed framework is applied to two case studies: (i) the implementation of the “30-by-30” policy in Singapore and (ii) the diversification of the aquaculture sector in terms of species and technologies in Norway, both up to 2040. The Singapore case study reveals that strong political action is needed to reach the target of 30% of self-sufficiency by 2030. Two of the developed cenarios allow reaching it and one of them allowed a significant decrease in imports. The Singaporean government should therefore introduce incentives for the development of innovative technologies, in particular of recirculating aquaculture systems and marine fishes farmed in sea cages close nd far from the shore, as these production categories are found to be associated with low environmental impacts and low land requirements during the farming stage. The Norwegian case study reveals that if Norway wants to remain a key actor on the global aquaculture stage with its current economic conditions, true diversification of its aquaculture sector is not possible. As a consequence, other economic studies should be include in the framework developed in this PhD work. Thus, in chapter 3, a critical literature review is conducted on LCA studies assessing aquaculture systems until mid- 2017. The analysis of 65 papers gives an insight on the main findings and remaining gaps conducted to identify which economic parameter(s) should be influenced to allow such drastic changes in the aquaculture landscape. In both case studies, increasing the proportion of trimmings in the manufacturing of fishmeal and fish oil is found to have important benefits as it reduces most of the environmental impacts, while replacing fishmeal and fish oil in fishes’ diets by insect-based meal and algal oil is found to increase them.

Chapter 6 discusses the operability of the framework, which was evidenced through the two very different case studies, and presents a number of improvement potentials regarding its feasibility and structure. The relevance of the framework for policy-makers is also defended therein. Finally, the main methodological limitations of the framework are reported and analyzed together with suggestions to overcome them in future works. It is concluded that to allow the framework to assess comprehensively the sustainability of aquaculture growth policies, the framework should evolve to an absolute sustainability assessment with environmental, economic, social and risk assessment modules, combined with system dynamics and accounting for all food sectors globally to truly consider all the consequence induced by the changes.

Chapter 7 summarizes the project outcomes and lists doctoral achievements in regard to the research questions. The manuscript ends with a synthetic table recapping all the recommendations emphasized throughout this PhD work to different target audiences, including aquaculture policy-makers and stakeholders, but also LCA practitioners and developers, food and resource economists, biologists and future practitioners of the developed framework.