1356 / 2024-09-25 10:36:33

Carbon footprint of shrimp (Litopenaeus vannamei) cultured in recirculating aquaculture systems (RAS) in China

carbon footprint,life cycle assessment,Recirculating aquaculture system,Litopenaeus Vannamei

Session 61 - Advancing Blue Food Futures Towards Ocean Conservation and Global Resilience

The development of "blue food" is a new solution for the food systems to address the human need for high-quality nutrition and reduce the environmental impact. Sustainable "blue food" has raised new demands and challenges for aquaculture technology. Recirculating aquaculture systems (RAS) is considered as a new way to solve the environmental problems of traditional fish farming, and it provides more alternative site selections for intensive farming. China is the largest producer of aquatic products in the world, and white leg shrimp Litopenaeus vannamei is one of China’s main aquaculture species, as well as a major crustacean species in global aquaculture. Based on the LCA method, this article aims to analyze and evaluate the global warming potentials (GWP) of L. vannamei farming which is currently booming in China, using the cases of four RAS systems and two different modes. A cradle-to-gate system boundary was used, covering infrastructure and aquaculture periods; the former includes construction and land use change (LUC), while the latter includes feed, energy and water consumption. Respiration carbon emission by cultured animals and reduction of GWP due to alternative energy substitution for system heating over the winter were also calculated. The results showed that the GWP of shrimps ranged from 13769.32 to 15124.17 kgCO₂-eq/t, as the functional unit was 1t wet weight of L. vannamei. Energy consumption was the main contributor to GWP, accounting for 50.6 ~ 53.2%, followed by biological carbon emissions (17.6 ~ 19.3%) and feed (15.9 ~ 18.1%). The use of photovoltaic power generation (572.52 kgCO₂-eq /t), wind energy (117.44 kgCO₂-eq /t) and other energy technologies can greatly reduce the GWP generated by coal-based thermal power generation technology (7340.01 kgCO₂-eq /t). The use of diesel, coal and natural gas as heat sources would generate an additional 6980 ~ 1169 kgCO₂-eq/t, and the use of electric energy will generate 39300 kgCO₂-eq/t. In this case, we believe that RAS can take advantage of more possibilities in site selection and make use of the full range of clean energy; Waste heat sources from other industries can be used to reduce energy consumption. By improving the efficiency of space use and waste water purification, and optimizing the farming mode and productivity, RAS may achieve the dual purpose of increasing production and reducing carbon emission, which is in line with sustainable development of “blue food”.