Composite indicators for multi-dimensional assessments of marine economic security in China

China possesses extensive maritime assets that offer substantial blue economic potential. However, balancing marine development and sustainability continues to pose governance challenges. This study introduces a novel framework to quantify marine economic security across China's regional marine sectors, identifying priorities to inform strategic governance reforms. We develop an original multi-dimensional index system encompassing industrial, technological, ecological, and administrative dimensions. Advanced modeling derives composite indicators to evaluate security levels across major marine zones. Key findings show China's marine economic security rose overall from 2006 to 2018 across three core zones but saw fluctuations owing to external jolts like the global crisis. The northern zone exhibited steady industrial security yet relatively slower tech advancements. The eastern zone experienced declines in industrial security due to export dependence, despite strong innovation ecosystems. The southern zone rapidly improved, harnessing strategic location and resources, though starting from a low baseline. Across all regions, ecological security rose, reflecting expanding sustainability, while administrative security stayed more constant. However, regional gaps persist, requiring tailored strategies based on local contexts. This study expands the scope of national economic security and offers tailored reform recommendations for more resilient, equitable, and efficient ocean development in China.