Microplastics: impact on marine animals and their remediation strategies

In the oceanic environments, the enormous pollution is caused by plastic-associated components of lesser size so called “microplastics” (MPs) at the global level. The diversified composition and chemical nature of MPs make them a potential complex pollutant in marine environments. As a result, affecting the growth and reproduction of living organisms like marine animals at various trophic levels contributing to perturbation in marine ecosystems . The current chapter focuses on the presence and impact of MP on marine animals belonging to Pisces, Mollusks, Echinoderms, and crustaceans. Different levels/types of toxicity were observed in marine animals based on some of the important factors like concentration, composition, size, and exposure period. The mode of toxicity also varied among the trophic levels depending on the size of the marine animals and their feeding habitats. Marine animals are known to ingest MPs either indirectly or directly through adsorption or filter feeders or via consuming the prey. In fishes, MPs are accumulated and translocated to various body parts causing tissue damage. In crustaceans and rotifers, metabolic disorders, endocrine disruption, and oxidative stress were induced by exposure to MPs. Hence it is crucial to develop novel strategies for enhanced protection of marine animals from MP toxicity. Assessment of MPs in aquatic environments and remediation technologies involving physicochemical methods and microbe-based degradation technologies were also discussed to maintain a sustainable marine ecosystem.