Application of a zoning approach in marine ecosystem health assessments: A case study of Jiaozhou Bay (China)

Abstract

In recent years, numerous methods have emerged for marine ecosystem health assessment, the majority of which have focused on model construction, indicator selection, and computational methods. However, limited attention has been given to spatial variations in the study area; thus, the spatial heterogeneity of regional ecosystem health has not been adequately captured. In this paper, we propose a zoning approach for the spatial delineation of ecosystem health, with Jiaozhou Bay as an example. Zoning of the target area is based on water exchange, pollution sources, etc. A hybrid methodology integrating the pressure–state–response (PSR) framework and the ecological quality ratio (EQR) was implemented for empirical analysis, and different assessment standards for specific indicators were adopted for various zones. With Jiaozhou Bay as a case study to verify the effectiveness of the zoning approach we proposed, we revealed different fluctuations in ecosystem health status between the overall and zoning results. On the one hand, overall status fluctuated between moderate and good levels from 2020 to 2022. On the other hand, good status was maintained in Zone A, whereas greater vulnerability was observed in other zones. These findings provide a reasonable depiction of the distinct characteristics and dynamic changes across different zones of the Jiaozhou Bay ecosystem. Such research provides robust support for marine development and management by relevant authorities while presenting a new perspective for ecosystem health assessments.