Enhancing the marine carrying capacity (MCC) is of important value in hastening the transformation of the marine economy and realising the marine economy high-quality development (MEHD). We explore the synergistic mechanism between the MCC and MEHD and its comprehensive indicator system, measure the synergistic relationship between China’s MCC and MEHD from 2006 to 2020 using the improved TOPSIS model and the composite system synergism model, and explore the influencing factors and their interactions using geographic probes. The research findings are (1) that China’s MCC and MEHD show a growing trend during the study period, in which marine green development is at a higher level and the cultivation of marine knowledge improves most significantly, but the general value of the MEHD is relatively low. (2) In terms of the synergistic relationship, the degree of ordering of the two shows a sustained rising trend, and the degree of ordering of the marine economy development as a whole is higher than the MCC; the degree of synergy is increasing, but the general value of synergistic development is low. (3) The main factors driving the MCC and MEHD are the marine consumption capacity, the marine opening, and the marine industrial structure; the explanatory power of most factor interactions tends to decrease, and the explanatory power of the interactions among the development of land-based economy, the marine industry structure, and the marine economy increase, and the impacts of the different factor interactions on the synergistic development are all greater than the factors. The influence of different factors on synergistic development is greater than the influence of each factor alone.

The integration of sea and land ecological economies is crucial for the development of a high-quality sea–land economy. This study explores and proposes the concept of a sea–land-integrated ecological economy. By constructing the evaluation index system for developing a sea–land-integrated ecological economy, the development level, evolution process, and development trend prediction of a sea–land-integrated ecological economy were evaluated and analysed in cities around the Bohai Sea from 2009 to 2019 using methods such as a model for assessing the development level, a spatio-temporal autocorrelation model, and an exploratory spatio-temporal data analysis model. The results of the study show that (1) the development level of the ecological economy of the cities of Bohai Rim’s sea–land integration generally had an upward trend; however, the magnitude significantly varied between cities; (2) the spatio-temporal autocorrelation pattern formed three major agglomerations with Dalian in the north, Yantai and Qingdao in the south, and Tianjin and Tangshan in the centre as the core cities and contained low agglomerations and scattered L–H spatio-temporal heterogeneous units; and (3) the integration prediction curve for 2020–2029 indicates that the level value for integration of most cities will improve over time.

人海经济系统韧性是检验海洋经济结构是否合理的重要依据。论文以适应性循环理论为核心引入社会生态系统韧性思维，界定环境敏感力、适应循环力、变化转型力三重属性韧性结构加以潜力、连通度、韧性维度的适应循环机制构建评估框架，应用熵权TOPSIS法、适应循环判别模型、空间联系引力模型分析环渤海地区人海经济系统适应循环与韧性时空异质性。结果表明：① 2012—2022年，环渤海地区人海经济系统适应循环“潜力—连通度—韧性”整体呈上升趋势，空间分布差异性趋同；② 2012—2022年，环渤海地区处于适应性循环中的开发阶段与保护阶段，处于正向循环，其中南部山东省城市带由开发阶段r向保护阶段k演进；③ 环渤海地区人海经济系统韧性时空上呈现平稳增强与集中分布的特点，空间联系上逐步形成多区域发展网络结构模式，以中、南部城市格局联系加强趋向整体化。研究可为沿海城市海洋经济可持续高质量发展提供理论参考与案例支撑。