Macroinvertebrate diversity as the bioindicators of freshwater ecosystem health: deterioration in physicochemical water quality parameters.

Freshwater ecosystems are robust, biodiverse, and important to sustain ecological balance and human well-being. They provide essential services such as water purification, nutrient cycling, fisheries, irrigation, and climate regulation. However, industrialization, agricultural intensification, and urban expansion have put huge pressure on these ecosystems, resulting in substantial decline in water quality and ecosystem integrity. Among various methods used to evaluate ecological condition, aquatic macroinvertebrates have emerged as prominent and reliable bioindicators of environmental change. Their sensitivity to alterations in water chemistry, habitat structure, and pollution gradients enables them to function as early warning signals of ecosystem stress. This review discusses findings from contemporary research across diverse biogeographical regions to evaluate how macroinvertebrate diversity reflects freshwater ecosystem health. The influence of physicochemical parameters-including pH, temperature, dissolved oxygen, and nutrient concentrations-on aquatic community composition is emphasized. Case studies from India, Chile, and the Philippines are presented to demonstrate the index performance of macroinvertebrate-based indices in assessing water quality. This study further identifies limitations of existing bioassessment frameworks in tropical contexts and proposes the integration of trait-based and multimetric approaches for comprehensive monitoring. By uniting ecological, chemical, and statistical perspectives, this paper emphasizes the importance of adaptive management strategies that balance human resource use with the conservation of freshwater ecosystem integrity.