Environmental Toxicology: Assessing the Risk of Agrochemicals on Aquatic Biodiversity

Abstract

Environmental toxicology increasingly focuses on the pervasive influence of agrochemicals on non-target ecosystems. Aquatic biodiversity, a cornerstone of ecological stability and human well-being, is particularly vulnerable to the influx of pesticides, herbicides, and fungicides used extensively in modern agriculture. Agrochemical runoff enters freshwater and coastal ecosystems, imparting sublethal and lethal effects on organisms across trophic levels. This research evaluates the risk posed by commonly used agrochemicals to aquatic biodiversity, synthesizing data from controlled laboratory studies and field surveys. The study integrates physiological, biochemical, and behavioral endpoints in key aquatic taxa, including plankton, macroinvertebrates, fish, and amphibians. Using standardized exposure protocols, we assessed lethal concentration (LC₅₀), enzymatic biomarkers (e.g., acetylcholinesterase inhibition), and community structure changes in relation to agrochemical gradients. Results indicate significant adverse effects even at environmentally relevant concentrations. Fish species exhibited hematological disturbances and oxidative stress responses; macroinvertebrate diversity declined sharply with increasing pesticide loads; phytoplankton exhibited shifts toward tolerant taxa, altering primary productivity. Two tables summarize toxicity thresholds and biomarker responses, while a graph depicts biodiversity indices relative to agrochemical concentration. Findings underscore the urgency for integrated risk assessment frameworks that combine chemical monitoring with biological indicators to inform regulatory limits. The discussion contextualizes agrochemical effects within global freshwater decline trends and explores mitigation strategies including buffer zones, precision application, and alternative pest management. This research underscores the necessity of interdisciplinary approaches to safeguard aquatic ecosystems from chemical stressors, offering insights for policy makers, ecotoxicologists, and conservation biologists confronting the complex challenge of harmonizing agricultural productivity with biodiversity conservation.