Owing to limited land resources and unique ecosystems, islands face more serious ecological risks under the interference of climate change and human activities. In this study, selecting Zhoushan Island as the study area, a landscape ecological risk index model was constructed based on LULC (land use/land cover) data and the landscape ecological risks for Zhoushan Island from 2000 to 2020 were analyzed. The results showed that: (1) From 2000 to 2020, the proportion of forest land and grassland remained above 70%, built-up land expanded from 52.67 km² to 123.52 km², and the beach area and ocean on the north side of the island decreased by 23.24 km² and 24.87 km², respectively; this was mainly converted into built-up land. (2) The number of landscape patches in Zhoushan Island decreased as the landscape ecological risk index decreased. The landscape ecological risk showed distinct spatial autocorrelation, with lowest-risk and medium-risk areas collectively accounting for 80% and higher-risk and highest-risk areas showing a decline. (3) The landscape ecological risks exhibited distinct spatiotemporal differences. Before 2010, the higher-risk and highest-risk areas were mainly distributed in the mudflat and ocean areas on the northern coast. After 2010, the higher-risk and highest-risk areas are mainly distributed in the central region, which comprises woodland, grassland, and built-up land.

Assessments of the ecosystem service value (ESV) and the social cost of carbon (SCC) inform national and government management decisions in the areas of human well-being and climate change mitigation and adaptation, respectively. Studying the correlation between the two provides a theoretical basis for low-carbon and high-quality regional development, achieving economic decarbonization, and improving human well-being. In this study, we take Zhoushan Archipelago as a case study, consider the ESV and SCC in Zhoushan Archipelago during the period 2010–2020, analyze their spatial development characteristics, and analyze the correlation between the two in time and space. The findings indicate that, with only a 1.5% change, the overall ESV in the Zhoushan Archipelago fell between 2010 and 2020. Conversely, there was a 1604.01 × 10⁴ t increase in net carbon emissions and a quick 2452% increase in SCC. During the study period, a substantial positive association was found between ESV and SCC in the Zhoushan Archipelago, according to the global spatial correlation analysis of the two variables. It passed the test for p-value. This study presents a new potential way to solve the environmental and economic difficulties caused by climate change by providing a mechanism for quantitatively assessing the environment from the perspective of monetary worth. In order to improve the ecological security pattern and ease the burden of regional carbon emissions, it is vital to make use of regional advantages, maintain forests, and develop blue-carbon resources such as mudflats. It is a good idea to cooperate regionally with nearby metropolitan agglomerations. The study’s findings are crucial for advancing sustainable development planning in the Zhoushan Archipelago, both theoretically and practically.

According to the life-cycle assessment method, in this study, we took the traditional plate cage (TPC) mariculture and deep water wind wave-resistant cage (DWWWRC) mariculture of large yellow croaker in China as the research object. We counted and calculated the carbon footprint of the whole life cycle of large yellow croaker cultured in Zhoushan. By analyzing and comparing the advantages and disadvantages of the two according to a perspective of carbon emissions, we found that the carbon footprint of DWWWRC was smaller than that of TPC, which is more suitable for China’s large yellow croaker mariculture. We proposed corresponding measures to reduce carbon emissions, such as using clean energy, extending cage life, and improving feed utilization. This study fills the gap in the current research direction of the carbon footprint of large yellow croaker farming in China and provides strong technical support for the sustainable development of China’s large yellow croaker cage farming industry.

Accurately analyzing the water system’s status in a region is crucial for mitigating water resource constraints on the development of island areas. This study centers on Zhoushan, an archipelago city, and employs the water footprint theory (WFT) and the logarithmic mean Divisia index (LMDI) model to scrutinize the evolution of water footprints from 2010 to 2020. It also dissects the impacts of economic, technological, and population factors on these changes. The findings are as follows: From 2010 to 2020, Zhoushan’s total water footprint has remained relatively stable, but its structure is imbalanced, indicating an unhealthy development. The agricultural water footprint dominates, though its proportion has steadily declined from 64% to 28%, while the imported water footprint has significantly increased from 2% to 29%. The skewed distribution of internal and external water consumption contributes to this imbalance, with internal water use accounting for a staggering 86.43%. The ecological security of water resources appears bleak, with average water scarcity and pressure indices reaching 0.42 and 0.41, respectively, indicating an overloaded state of water resources. Despite a 144.50% growth in water footprint efficiency from 2010 to 2020, the average water resource sustainability index merely stands at 0.531, and its sustainability remains precarious. The LMDI model results unveil that technological factors are the primary negative driving factors, contributing to 47.06% of the changes in Zhoushan’s water resource utilization. Conversely, economic and population factors play positive roles, contributing 42.29% and 10.65%, respectively. Therefore, in the course of development, there should be a focus on promoting water-saving tec-nologies, and continuously enhancing the efficiency of water resource utilization. Simultaneously, attention should be given to the development of the tertiary sector and the water resource pressure resulting from the mobile population, aiming to achieve sustainable water resource utilization and further ensure the ecological security of Zhoushan City.

The dynamic change in the shorelines reflects an important sign to the socio-economic development of coastal areas. The Huizhou–Shanwei region of China has experienced rapid socio-economic development over the past 33 years. The study of the dynamic change in the shorelines in this region can provide basic data support for the marine environmental protection and regional development planning in this region. Based on Landsat RS (remote sensing) images from 1990 to 2023, this study obtained the length and structure data of the shorelines in eight periods by manual visual interpretation. DSAS (Digital Shoreline Analysis System) and other methods were also used to calculate indices such as EPR (End Point Rate) and fractal dimension of the shorelines The results show that, during 33 years, the length of the shorelines increased 15.83 km, with an average growth rate of 0.48 km/y; the value of the intensity of change in the shorelines was 0.08%; the average EPR was 3.66 (m/y), and the artificiality index of the shorelines increased from 0.2895 to 0.4295; the greatest intensity of change was in the estuarine shorelines, with an intensity of change of −2.69%. The overall change in the fractal dimension of the shorelines was small, both between 1.0395 and 1.0673; the shorelines became slightly more curved. As far as the influencing factors are concerned, the influence of the natural environment is a long process, and human activities are more capable of changing the length and shape of the shorelines in a short period of time, with factors such as the degree of economic development having a greater impact on the shorelines.

In the context of global warming, thermal environmental problems in coastal urban ag-glomerations have become increasingly prominent. This study focuses on the urban ag-glomeration around Hangzhou Bay, constructs annual heat island intensity classification maps based on MODIS summer land surface temperature (LST) data from 2000 to 2020, analyzes the spatiotemporal patterns of heat islands, and investigates their driving mechanisms using the Extreme Gradient Boosting and Shapley Additive exPlanations (XGBoost-SHAP) model. The results show that: (1) the high-frequency area of strong heat islands expanded by 62.10% during the study period, extending from early built-up areas to newly developed coastal zones, with the spatial pattern transitioning from point-like distribution to areal agglomeration; (2) significant differences exist between the north and south coasts, where strong heat island center migration on the north coast is consistent with impervious surface expansion, whereas the south coast is significantly influenced by coastal wetland siltation; (3) impermeable surfaces and wind speed are key factors affecting LST, with impermeable surfaces acting as the primary driver of temperature increase, while wind speed plays a significant role in moderating temperatures. This study provides a scientific basis for thermal environment regulation in coastal urban agglomerations.