Ecological health assessment and sustainability prediction in coastal area: A case study in Xiamen Bay, China

Bay areas are special ecological transition zones where land and sea meet, and the ecological health of the region is an essential foundation for sustainable development. Therefore, it is crucial to establish an ecological health evaluation index system to assess the ecological health sustainability in bay areas for developing coastal zone management plans. This study proposes a cross-jurisdiction framework for assessing the ecological health in Xiamen Bay at multi-scales and multi-levels. The entropy weight and comprehensive index methods are then used to evaluate the ecological health in Xiamen Bay coupling ecological integrity and biodiversity with ecosystem services. Finally, a system dynamics model was established to analyze the sustainability of ecological health in Xiamen Bay. The results show that the overall ecological health level in Xiamen Bay continuously maintained <0.6 from 2005 to 2018, which is locating at critical and early warning status, and a shift from critical to good status starts in 2021; (2) under conditions of current development, the future population density, the total number of tourists arrived, artificial shoreline length, patch density, landscape diversity, habitat, and estuarine nutrient fluxes achieve the early warning status, which greatly constraining the sustainability of regional ecological health; (3) Global Orchestration is the most desirable ecosystem management model for the future. The ecological health in Xiamen Bay will achieve 0.7 and above in 2025 if following Global Orchestration pattern. This health value is locating at “good” status, and closes the gap to ecological sustainability level (ideal status with 0.8) in the region. This model is critical to form strategies and to ensure the ecological sustainability in the region.