An Integrated Ecological Framework for Evaluating Agricultural Runoff Impacts on Aquatic Ecosystem Sustainability

This research was intended to investigate the effects of agricultural runoff on aquatic ecosystem sustainability based on physicochemical, nutrient, and biological parameters. Samples of water and biological components were collected from reference, runoff entry, and downstream locations. The physicochemical, nutrient, and biological parameters were examined and used to construct an index known as the Aquatic Ecosystem Sustainability Index (AESI). The environmental quality at the runoff entry points had degraded significantly. Total nitrogen content rose from 2.47 to 8.96 mg/L, while total phosphorus content rose from 0.18 to 0.84 mg/L compared to the reference locations. The taxonomic richness dropped from 31.4 to 20.7, and the macroinvertebrate integrity index fell from 76.4 to 51.7. AESI scores were generally lower at the runoff-entry sites (54.9) compared to the reference sites (83.7), with the downstream sites having a slightly higher score (62.5), suggesting some level of improvement. Agricultural runoff led to nutrient enrichment, decline in water quality, biodiversity, and ecosystem sustainability. This study illustrates the significance of adopting an ecosystem approach for evaluating the effects of runoff and the importance of improving agricultural runoff management.