Influencing factors and spillover effects of marine ecological efficiency in Chinese coastal regions

This paper investigates the complicated factors influencing marine ecological efficiency (MEE) within the context of spatial sustainable development and local government administration. Drawing from panel data encompassing 54 Chinese coastal regions between 2011 and 2023, we design a Super-Slacks-based model to evaluate the regional MEE, two entropy weight methods to evaluate the regional digital economy (RDE) and the land–sea coordination (LSC), respectively. This paper presents a spatial Durbin model to explore the spatial features of MEE and the spatial relationships between various factors and MEE. The visual scatter graph of RDE and MEE shows they are linearly dependent but they cluster in two groups, which is explained by the reinforcement effect of the LSC strategy. The empirical findings reveal that MEE is positively autocorrelated in the coastal regions and MEE hot spots have mainly clustered in the Shandong Peninsula, the Yangtze River Delta, and the Pearl River Delta while the MEE cold spots have gradually dropped. Both RDE and LSC have a positive spillover impact on neighbors’ MEE, but the structure of industries, the foreign trade dependence, and the gross industrial production have a negative spillover impact on neighbors’ MEE. However, their indirect spillover effects are much less than their direct effects. Moreover, the influence mechanism test reveals that RDE has a positive effect on improving MEE with the technological innovation level as a partial mediator and LSC as a positive moderator. LSC strengthens the RDE's influence on MEE in those regions with higher LSC.