Coordinating land-ocean economic interaction to enhance marine natural capital and drive objective blue well-being

Blue economy relies on a healthy ocean, where marine natural capital supports ocean industry activities and sustain the blue well-being that refers to a positive state for people which is determined by coastal and marine space. For coastal countries dominated by land-based economies, such as China, the development of the ocean industry is largely influenced by local land-based economies, which have significant impacts on the sustainable provision of blue well-being from marine natural capital. However, effects of land-ocean economic interaction on the exploitation of marine natural capital and blue well-being remain unclear. To fill these gaps, we quantified the marine natural capital of Chinese coastal waters at the county level, then explored the relationship between marine natural capital distribution and utilization, and land-ocean economic coordination level over a decade. We constructed an index of marine natural capital efficiency (MNCE) to reflect both the socioeconomic and natural wealth carried by per unit blue space and to determine which coastal regions’ marine natural capital were more effective in prompting objective blue well-being. The results indicate that the land-ocean economic coordination level has a significant positive association with MNCE. Marine natural capital in the coastal regions with low land-ocean economic coordination level are generally less efficient in objective promoting blue well-being. Based on an inter-regional coalition model, we offer recommendations for China’s coastal regions to select optimizing economic cooperation coalitions. Under the recommended coalition scenario, an improved land-ocean economic coordination level could increase the overall MNCE in China by 60.19%. This could either enhance the available marine natural capital flow by 69.89% or increase the ocean industry production by 69.68%, which could boost objective blue well-being through the efficient use of natural capital to promote broader ocean economy growth. We suggest strengthening regional cooperation and coordinating land-ocean economic interactions to boost objective blue well-being for coastal communities by using marine resources efficiently and equitably.