Synergistic Evolution and Prediction of Green Development Efficiency and Inclusive Growth in China’s Marine Economy

Against the dual backdrop of global ocean governance and food security, promoting the coordinated development of marine economic green development efficiency and inclusive growth is of significant practical importance for countries to improve marine ecology, narrow the wealth gap, and safeguard blue granary security. This study takes China’s three major marine economic circles and 11 coastal provinces from 2002 to 2024 as research subjects, employing methods including the Super-efficiency SBM model, the CRITIC-TOPSIS, Haken model, kernel density estimation, the Dagum Gini coefficient, and the ARIMA time series model to measure the spatiotemporal evolution of the synergy between marine economic green development efficiency and inclusive growth, as well as to forecast future trends. The results indicate that (1) the synergy level of the three major marine economic circles has been continuously increasing, with the full coastal zone’s synergy level rising from 0.48 in 2002 to 0.81 in 2024, with inclusive growth playing a dominant role throughout the period; (2) the synergy level of all Chinese provinces has been continuously improving with narrowing disparities—the Gini coefficient declined from 0.252 to 0.072, and the hypervariable density contributed an annual average of 47.22%; and (3) forecasts show that, from 2025 to 2029, the full coastal zone’s synergy level will rise from 0.82 to 0.84, with all economic circles showing an upward trend. The findings of this study can provide references for global coastal economies in formulating marine green sustainable development policies.