Effect of the marine system on the pressure of the food–energy–water nexus in the coastal regions of China

Food, energy and water are important resources for national development and human life, the conflicts among three have become more acute especially in coastal regions, but most existing studies focused on land. To investigate the effects of marine resources on relieving the pressure of the food–energy–water (FEW) nexus in the coastal regions of China and its state changes, the concept and computing method of marine equivalent food, energy, and water resources was proposed to quantify the supply of marine resources, meanwhile, this study constructed a pressure index model of food, energy, and water resources from the perspective of average possession of resources. To the best of our knowledge, this is the first FEW nexus study based on a marine resource perspective. The results shown that, during the study period, (1) Fujian had the most marine equivalent food production accounts for 44% of the terrestrial food yield; the marine equivalent energy made Shandong and Hainan to be a major province of energy; and marine equivalent virtual water was equivalent to 6% of the annual water consumption. (2) the food pressure in the south of the Yangtze River was much higher than that in the north; the water pressure was the opposite, and the energy pressure was high in all coastal regions of China. Considering the supply of marine resources, the FEW nexus pressure was alleviated by more than 10% in nearly half of the coastal provinces and cities. Moreover, valuable suggestions were propounded to each area targeted, which provide references and suggestions for alleviating the pressure of the FEW nexus not only in China's coastal region, but also have implications for resource flows in other regions. Also, the findings of this study contribute to a more comprehensive understanding and protection of the ocean, and promote regional sustainable development.