Micro-by-micro interactions: How microorganisms influence the fate of marine microplastics

Microorganisms drive the biogeochemical cycles that link abiotic and biotic processes in the aqueous environment and are intricately associated with plastic debris. The presence of microplastics in water and sediment introduces new concerns as small particle size allows for increased pathways of microplastics in the food web and element cycles. In this review, we present the current state of knowledge on microbe-plastic interactions and summarize the potential impact of biogeochemical processes on plastic distribution, cycling, transport, and sedimentation. We explore how microbe-plastic interactions influence the exposure of consumers to microplastics and plastic degradation products. Key methods used to elucidate biofilm development, microbial biodegradation, and microplastic detection in the aqueous environment are discussed. Finally, we comment on potential future questions and research directions needed to further define the role of microorganisms in the environmental fate of microplastics.