Impact of Microplastics on the Physiology of Benthos

Microplastic pollution presents a great menace to the biodiversity occupying aquatic ecosystems by accumulating in benthic environments and adversely affecting biocenoses globally. Microplastics are globally responsible for being a major source of plastics in freshwater and marine environments. Benthos, the bottom-dwelling communities, are likely to combat extreme pressure from microplastics. The content of microplastic fragments revealed the taxa-specific accumulations usually in the digestive tract in benthic organisms. Microplastic interferes with benthos by reducing feeding capacity, lowering energy reserves, slow growth, low reproduction, body deformations, abnormal behavior, affecting lipid metabolism, and interference with swimming. The gastropods and the bivalves exhibit the presence of microplastics, and the filter feeders display the highest quantity of microplastics. Microplastics contribute adversely to the growth and development of benthos. Some adverse effects include reduced growth, inflammation, decreased acetylcholinesterase activity, decreased swimming speed, and intestinal injury. For example, growth inhibition in the sandworm (Annelida), inhibition in the feeding and growth of urchins (Echinodermata), and neurotoxicity in mussels (Mollusca) are caused by microplastics. Microplastics absorb potentially toxic pollutants and contribute to their transfer across the food chain consequently inflicting indirect effects on the benthos. Microplastics have an established adverse impact on the physiology of benthos in marine and freshwater ecosystems, which ultimately have ecological consequences. Microplastic management strategies include minimizing the microplastic input into marine ecosystems, restricting single-use plastics, reusing, and recycling plastics, and microbeads. The legislation to curb plastic production and usage, social awareness campaigns, and research initiatives to restrict the entry of microplastics into aquatic ecosystems could save benthos from this adversity.