Microplastic Contamination in Labeo rohita and Freshwater Ecosystems: A Comprehensive Review of Sources, Occurrence, Biological Impacts, and Food Safety Implications

Microplastic Contamination in Labeo rohita and Freshwater Ecosystems

Abstract

Abstract

Background: Microplastic pollution has become a major environmental and public health concern due to its widespread distribution in freshwater ecosystems. Freshwater fish, particularly Labeo rohita (Rohu), are highly vulnerable to MP contamination because they ingest contaminated water, sediments, and food. As one of the most commonly consumed fish species in Pakistan, contamination of L. rohita poses potential risks to aquatic biodiversity and human health through food-chain transfer. Objective: This review aims to summarize the current knowledge regarding the sources, classification, occurrence, and biological impacts of microplastics in freshwater ecosystems, with particular emphasis on their effects on Labeo rohita and the implications for environmental and food safety. Discussion: Microplastics originate from both primary and secondary sources and enter freshwater systems through wastewater discharge, industrial effluents, agricultural runoff, atmospheric deposition, and plastic waste degradation. Studies have demonstrated that MPs accumulate in the digestive tract and tissues of freshwater fish, leading to intestinal blockage, inflammation, oxidative stress, impaired nutrient absorption, kidney dysfunction, gill damage, immune suppression, reproductive toxicity, and altered gene expression. Owing to its ecological importance, feeding behavior, and widespread human consumption, L. rohita serves as an effective bioindicator for monitoring freshwater microplastic contamination. Conclusion: Microplastic pollution represents an emerging threat to freshwater ecosystems, fish health, biodiversity, and public health. Increasing contamination highlights the urgent need for continuous monitoring and scientific investigation, particularly in developing countries such as Pakistan. Recommendation: Future research should establish standardized monitoring protocols, investigate long-term toxicological effects, strengthen plastic waste management strategies, and promote public awareness and policy interventions to reduce microplastic pollution and safeguard freshwater ecosystems and food safety.