Objective The effectiveness evaluation of national park conservation management is an essential component of national park assessment and evaluation. To address the existing issues in current marine protected area conservation management effectiveness evaluation, such as insufficient ecological indicators, strong subjectivity, and the lack of adequate consideration for marine-specific attributes in the "National Park Assessment and Evaluation Standards", this study attempted to construct a conservation management effectiveness evaluation indicator system applicable to marine protected areas and to conduct an empirical test.

Methods Guided by the Composite Ecosystem Theory and adhering to the principle of "Ecological Conservation as the Primary Goal", this research constructed an evaluation indicator system for assessing conservation management effectiveness of the Changdao national park candidate area. The weights of individual indicators were determined by combining the Analytic Hierarchy Process (AHP) and the Criteria Importance Through Intercriteria Correlation (CRITIC) method. A comprehensive evaluation model was then applied for quantitative analysis of the candidate area's conservation management effectiveness. Furthermore, a Coupling Coordination Degree model was utilized to analyze the mutual influence and linkage between the social, economic, and ecological systems, assessing the overall state of synergistic development within the systems.

Results The conservation management status of Changdao National Park candidate area in 2023 was evaluated. The results showed that the constructed evaluation system for conservation management effectiveness was operational and provided a valuable methodological supplement to the existing "National Park Assessment and Evaluation Standards."

Conclusions The overall conservation and management effectiveness of Changdao National Park candidate area showed a slight improvement compared to the previous year, with the coupling and coordination degree of the social, economic, and ecological systems remaining moderate-to-low level. The methodological framework developed in this study offered a decision-support reference tool for the management of marine-type national parks and their corresponding local governments.