Ocean warming shapes the marine plastisphere: Microbial assembly, vector effects, and biogeochemical feedbacks of...

Marine microplastic pollution has evolved into a global ecological crisis, shifting from physical contamination to microbial habitats on plastic surfaces. The colonization of microorganisms on synthetic surfaces is not random but is driven by physicochemical and biological factors. This narrative review summarizes the properties of microplastics that influence the composition and assembly of microbial communities. We emphasize that polymer types (e.g., polyethylene and biodegradable polylactic acid) act as primary templates, whereas surface interface properties, including hydrophobicity and adsorption of natural organic matter and biomolecules, determine attachment kinetics. We address the size-dependent effects of microplastics, focusing on how nanoscale particles cause greater oxidative stress than micron-scale particles. Beyond community structuring, microplastics serve as vectors facilitating the long-distance migration of marine pathogens and the horizontal transfer of antibiotic resistance genes, thereby expanding the geographical range of ecological risks. Significantly, bidirectional interactions within the plastisphere (the microbial community and associated biofilm that develop on plastic surfaces) reshape marine biogeochemical cycles. By altering the buoyancy and sinking rates of organic aggregates in the water column, microplastic-microbe aggregates perturb the biological carbon pump and modulate nitrogen transformation processes. This review provides an updated framework that integrates ocean warming into predictive ecological models for plastisphere assembly and function, addressing a gap in climate-microplastic research. Using mechanistic insights from 2010 to 2025, we identify critical knowledge gaps and advocate for advanced multi-omics and stable isotope probing to characterize the functional metabolic pathways of the plastisphere in a changing ocean.