To conduct a comprehensive evaluation of resource utilization efficiency, an efficiency assessment framework that combined multi-regional input-output analysis and data envelopment analysis was proposed. This framework was employed to calculate the water, energy, and food footprints on the consumption side of cities in Guangdong Province. On this basis, input-output efficiency under the influence of inter-regional trade was assessed from the perspective of the water-energy-food system. The findings indicate that the cities’ water, energy, and food footprints on the consumption side are predominantly influenced by inflows from regions outside the province, followed by local consumption footprints. Other cities within the province receive a relatively negligible proportion of trade-implied resources. The spatial distribution characteristics of the water-energy-food system efficiency and the water, energy, and food footprints on the consumption side converge, primarily exhibiting a decreasing trend from the The Pearl River Delta region to the exterior. By taking into account the impact of inter-regional trade on water, energy, and food consumption, the efficiency of most cities has been improved, and the overall efficiency of the region has increased. Among the cities, Shenzhen and Zhongshan have demonstrated optimal input-output allocation, while the remaining cities have exhibited varying degrees of input redundancy, with Guangzhou exhibiting the greatest potential for resource savings.

Carbon sink fisheries are an important means of producing blue carbon and contributing to carbon neutrality, with significant economic and environmental benefits. However, the implementation of carbon sink fisheries involves multiple parties and is a dynamic game. Existing studies have rarely analyzed carbon sink fisheries as an entry point to include governments, aquaculturists, and enterprises in the system at the same time. Against the background of the success of the pilot projects in Lianjiang and Putian, exploring blue carbon trading based on the perspective of carbon sink fisheries will help to provide scientific recommendations. Therefore, a tripartite evolutionary game model involving local governments, aquaculturists, and enterprises was constructed, and the impact of each subject's strategy choice on the stability of the system was analyzed. The results show that (1) subsidies for carbon sink fisheries have a dual effect on the evolutionary process. Within a certain range, moderate subsidies for carbon sink fisheries can motivate aquaculturists to shift to carbon sink fisheries, but too high subsidies level can cause a heavy financial burden and force the government to give up. (2) The difference between the price of subsidized blue carbon and the carbon tax is a key factor affecting the strategy choice of enterprises. When the price of subsidized blue carbon is lower than the carbon tax, enterprises tend to purchase blue carbon, and the lower the price of subsidized blue carbon, the faster the response of enterprises. (3) Based on the initial scenario, a moderate increase in the subsidy level of the local government can lead the three-party evolutionary game to the ideal outcome. Under this subsidy level, no matter what the initial probability of each party is, it will not affect the realization and continuation of the ideal outcome.