Research Progress and Prospects of Aquatic Ecological Assessment

Abstract

Aquatic ecological assessment serves as the core technical support for the transition of watershed water environmental management from water quality target-oriented to ecological health target-oriented. Based on representative Chinese and English literature indexed in CNKI and other databases over the past four decades, this paper systematically reviews the conceptual connotation, theoretical basis, indicator system and methodological evolution of aquatic ecological assessment. The review shows that mature research paradigms have been established internationally, represented by the Index of Biotic Integrity (IBI) and Rapid Bioassessment Protocols of the United States[1], ecological status assessment under the EU Water Framework Directive (WFD)[2], and the Australian River Assessment System (AUSRIVAS). In China, aquatic ecological assessment has evolved from physicochemical water quality assessment and single-discipline biological assessment toward comprehensive multi-factor assessment integrating physical, chemical and biological components[3]. A national standard system has been preliminarily established, represented by GB/T 43476—2023 Technical Guidelines for Aquatic Ecological Health Assessment[4]. At the current stage, several bottlenecks remain, including inconsistent methodologies and poor comparability of assessment results in reference condition determination, aquatic ecoregionalization, indicator weighting, and stressor identification. Future efforts should prioritize the integration of emerging monitoring techniques such as environmental DNA (eDNA) with conventional approaches, develop machine learning-assisted comprehensive diagnostic methods using multi-source data, and accelerate the construction of a closed-loop technical framework covering assessment–diagnosis–restoration.