The process by which the concentration of harmful contaminants rises at successive trophic levels in an aquatic food chain is known as biomagnification. Through agricultural runoff, industrial discharge, urban wastewater, atmospheric deposition and persistent pollutants such heavy metals, pesticides, herbicides, microplastics, oil hydrocarbons and industrial effluents infiltrate aquatic environments. These contaminants build up in aquatic species and grow more concentrated in higher trophic levels, especially in predatory fish, aquatic birds and mammals, since they are resistant to degradation. Numerous ecological effects of biomagnification include neurotoxicity, immunological suppression, developmental anomalies, reproductive impairment and increased mortality. Additionally, it reduces biodiversity, modifies community structure, disturbs food-web dynamics and lowers ecological productivity. Additionally, microplastics facilitate the spread of contaminants across food chains by acting as transporters of hazardous substances. Consuming seafood puts human health at serious risk due to the buildup of contaminants in commercially relevant fish species. To reduce biomagnification and preserve the sustainability of aquatic ecosystems, efficient pollution control and environmental monitoring are crucial.