Evaluating the Impacts of Genotoxicity on Fish Health and Population Dynamics: A Review of Xenobiotic Stressors in Aquatic Ecosystems

Aquatic ecosystems are increasingly threatened by xenobiotic pollutants released through agricultural runoff, industrial discharge, domestic wastewater, pharmaceutical residues and other human-related activities. These contaminants may persist in water bodies, accumulate in fish tissues and interfere with normal biological processes, including the integrity of genetic material. Fish are important indicators of aquatic ecosystem health because they are continuously exposed to contaminants through the gills, skin, sediments and food chain, making them useful organisms for assessing environmental pollution. This review examines the impacts of xenobiotic-induced genotoxicity on fish health and population dynamics, with emphasis on DNA damage, biomarkers of exposure, reproductive impairment, growth reduction, survival decline and ecosystem consequences. The article is based on a secondary-sourced narrative review of relevant literature on aquatic pollution, genotoxic mechanisms, fish toxicology, biomarkers and environmental management. Findings from reviewed studies indicate that xenobiotics such as pesticides, heavy metals, hydrocarbons, pharmaceuticals and endocrine-disrupting chemicals can cause DNA strand breaks, micronuclei formation, chromosomal abnormalities, oxidative stress and impaired DNA repair in fish. These effects may weaken immunity, reduce growth, affect reproductive performance, alter sex ratios, lower recruitment and contribute to population decline. The review concludes that genotoxicity should be treated not only as a cellular problem but also as an ecological and public health concern. Regular biomarker-based monitoring, improved wastewater treatment, stricter pollution control and effective enforcement of environmental regulations are recommended to protect fish populations, aquatic ecosystems and human health.