An assessment of the environmental performance of seafood and the implications for food systems

Food security is underpinned by the sustainability of the global food system. The production and supply of food is responsible for global environmental impacts and a transition to a sustainable food system is required. Seafood plays a key role in the food system, as a vital source of protein and essential nutrients, yet fisheries and aquaculture are often left out of discussions on food and nutrition security. The broader impacts of seafood as part of the food system are rarely considered through current sustainability assessments. The result is that the environmental impacts generated from the supply and consumption of seafood products are not well understood. Life cycle assessment (LCA) is a practical and credible tool for assessing the environmental footprints of food products and production methods. LCAs of seafood have increased substantially over the past decade, encompassing a range of species, production methods, and geographic locations. Nevertheless, the field lags behind LCA of terrestrial systems in terms of both empirical coverage and methods. This thesis expands the literature on seafood LCAs, using Australian seafood case studies. The aim is to improve the understanding of the environmental impacts of seafood production and consumption as a part of the broader food system, and to identify opportunities to advance seafood sustainability concepts and practice. The thesis consists of five papers which are linked through the LCA framework, and have a strong emphasis on seafood as part of a sustainable food system, and on the nexus between LCA and contemporary fisheries management principles and practices. In the first paper LCA is used to measure the environmental performance of the white banana prawn (Fenneropenaeus merguiensis) from the Australian Northern Prawn Fishery across its supply chain. Management of this fishery has been promoted as a sustainable model for other countries to emulate, although broader environmental impacts, such as those relating to energy and water use or greenhouse gas emissions are not currently monitored. Fishing operations were the main source of impacts, while processing and storage were key contributors to ecotoxicity, and transport made a negligible contribution to any impact category. This research highlighted the scope to develop the application of LCA in wild capture fisheries in terms of complementing existing fisheries management, and through the development of fishery-specific indicators to improve the efficacy of seafood LCAs. There is a need for information to better understand the relationship between seafood LCAs and fisheries management. In the second paper LCA was used to measure the environmental footprint of the supply of Tasmanian southern rock lobster, Jasus edwardsii (TSRL) under different management scenarios. The environmental footprint of the TSRL in the scenarios modelled was responsive to marine resource management decisions made inside and outside the fishery. Targeting maximum economic yield rather than maximum sustainable yield decreased the carbon footprint by 80%. Limiting access to the fishery by increasing the coverage of marine protected areas increased the fishery's carbon footprint by 23%. Better understanding of the environmental impacts resulting from management changes will be vital in a future of increased carbon emission reporting and regulation. The application of LCA to marine resource decision-making can help ensure decisions are not made in isolation of broader environmental impacts. The lobster LCA also highlighted that the international airfreight of live lobsters was the major contributor to global warming potential (GWP) and cumulative energy demand (CED). The distance between where food is produced and consumed is increasing, and is often taken as evidence of an unsustainable global food system. Seafood is a highly traded commodity and in the third paper LCA was used to examine the impacts of the movement of products beyond the fishery or farm to better understand the environmental impact of seafood as part of the broader food system. The carbon footprints of the production and distribution of select seafood products that are consumed in Australia were compared to determine differences in the sustainability of imports and their domestically produced counterparts. The distance food is transported was not found to be the main determinant of carbon emissions. Despite the increased distance between production and consumption, carbon footprints of meals from imported seafood can be similar to meals consisting of domestically produced seafood, and sometimes lower, depending on the seafood consumed. In combining LCA with existing seafood sustainability criteria the trade-offs between sustainability targets become more apparent. While the addition of carbon footprinting to current seafood sustainability assessments broadens their perspective, the carbon footprint should not be taken as a complete measure of product sustainability in LCA. A combination of relevant LCA indicators can provide a more holistic assessment of overall seafood sustainability. However, while LCA is a well-developed and useful tool for assessing carbon emissions and other biophysical impacts, it is lacking in the assessment of fishery specific impacts. Several new methods have been proposed in recent years to account for fishing impacts on ecosystems and biotic resources through LCA. In the fourth paper, a new method is proposed to complement these advances through accounting for impacts of fishing on biodiversity as a measure of naturalness of the seafloor and pelagic habitats. The method has been adapted from its original terrestrial application and incorporates elements of existing seafood certification schemes and marine ecological risk assessment. It is a contribution to the much needed improved application of LCA to wild-capture fisheries. In the final paper, a literature review is conducted to examine how the environmental performance of seafood is integrated and interpreted within the rapidly growing body of literature on sustainable diets. Seafood is examined in terms of its reported comparative performance to agricultural products and in its role in a sustainable food system. Seafood diets typically have lower carbon footprints than meat diets and higher footprints than vegetarian diets. However, many studies do not adequately address seafood and thereby overlook the opportunities and limitations of including seafood as part of a sustainable diet. LCA is used in this thesis to assess the environmental impacts of seafood and to expand the concept of sustainability of seafood, however, fisheries, aquaculture and their supply chains remain often neglected, yet critically important, parts of healthy and sustainable food systems. This research brings seafood a step closer to adequate representation in food systems research, although further development of seafood LCAs and better methods for comparing seafood and agricultural production systems are required. More of this type of research is therefore needed to ensure that seafood is included in future food and nutrition security discourse.