Integrating polycyclic aromatic hydrocarbons risk into lake health assessment: A diagnostic framework for ecosystem integrity and services in Dongping Lake, China

Accurate and systematic assessment of ecosystem health is essential for formulating effective conservation and restoration strategies in lake ecosystems. Current assessment frameworks demonstrate significant limitations in comprehensively addressing emerging contaminants and ecosystem services from an integrity-based perspective, thereby failing to meet contemporary demands for lake ecological restoration and management. Here, we propose a novel lake health assessment framework that addresses these critical gaps by systematically incorporating polycyclic aromatic hydrocarbons (PAHs) as key indicators of ecological stress while establishing explicit linkages between ecosystem integrity and service provision. Through systematic literature review, expert consultation, and stakeholder surveys, we developed a multidimensional indicator system encompassing organism integrity, habitat integrity, material processes, hydrological processes, and ecosystem services. Applied to Dongping Lake, an integral hydraulic node in China's Yellow River Basin. The framework revealed an overall "Healthy" status, albeit with notable spatial and functional heterogeneity. Importantly, incorporating PAHs ecological risk identification highlighted a "Moderate Risk" level that significantly constrained material process integrity. Network analysis further uncovered key system interactions, pinpointing four leverage points (macrophyte coverage, shoreline development, dissolved oxygen, and public satisfaction) for management intervention and quantifying a fundamental trade-off between water supply provision and ecological integrity. Spatially, the Northern of lake exhibited the most degraded conditions, whereas the Central zone demonstrated optimal ecological performance. Our framework offers a robust, scientifically grounded tool for lake management, underscoring the necessity of integrating emerging contaminants into monitoring regimes and advocating spatially tailored management strategies informed by network interactions. Specifically, the findings support the development of zone-specific management plans and optimization of water resource allocation to balance provisioning services with ecological integrity. This approach provides a transferable model for assessing and managing lake ecosystems under multiple stressors in rapidly developing regions, advancing both theoretical and practical dimensions of sustainable lake management.