The Digital: A Catalyst for Accelerating the Quality Improvement and Sustainable Development of China’s Marine Industry

The sustainable development of the marine industry is a vital pillar for achieving global ecological balance and economic prosperity. As a crucial repository of resources and a vital regulator of climate, the ocean plays an irreplaceable role in supporting humanity’s long-term development. Against this backdrop, digital technology drives modern development, supporting decision-making and resource allocation while profoundly transforming industrial models. The resulting digital economy has become one of the core drivers of sustainable global economic growth. Given the close connection between the marine industry and the digital economy, attention has been drawn to whether a correlation exists between their respective growth rates. This study employs a Panel Vector Autoregression (PVAR) model based on panel data from China’s coastal provinces between 2012 and 2023. The empirical analysis reveals: (1) After a certain period, the growth rates of the digital economy and the quality development of the marine industry exhibit a mutually reinforcing trend. Furthermore, the innovation coupling coordination rate and the upgrading rate within the marine industry also strengthen each other, injecting endogenous momentum into the sustainable development of the marine sector. (2) When simulating external shocks through local government expenditure, it was found that while local government spending positively impacts the growth rate of the digital economy, its effect on the quality development rate of marine industries is limited, exhibiting a “single-helix” upward trend. This suggests the need to optimize the precision of policy support to better balance the coordinated sustainable development of the digital economy and marine industries. (3) The growth rate of the digital economy exerts a dual threshold effect on the quality development of marine industries. That is, there are two thresholds: 0.0099 and 0.0725. Initially, the promotion effect is relatively small with a positive and significant coefficient of 0.120. When exceeding the first threshold, the coefficient becomes 0.416, which is positively significant. When exceeding the second threshold, the promotion effect disappears. This necessitates differentiated strategies tailored to distinct developmental stages to propel marine industries toward high-quality, sustainable development empowered by the digital economy. Based on these findings, this study focuses on the relationship between the growth rates of the digital economy and marine industries, offering actionable recommendations for marine nations like China to advance high-level sustainable industrial development.