Temporal succession of marine microbes drives plastisphere community convergence in subtropical coastal waters

Marine plastic pollution is a pervasive environmental issue, with microplastics serving as novel substrates for microbial colonization in aquatic ecosystems. This study investigates the succession of plastisphere communities on four common plastic types (polyethylene, polypropylene, polyethylene terephthalate, and polystyrene) in subtropical coastal waters of Hong Kong SAR. Over a 42-day period, we analysed the temporal development of microbial communities using a three-domain universal metabarcoding method. Our results reveal that temporal succession is a stronger driver of community structure than plastic type, with prokaryotic communities converging across different plastics as biofilms mature. Despite this convergence, plastisphere communities remain distinct from planktonic communities throughout the experiment, suggesting that plastics create unique ecological niches in marine environments. We observed differences in diversity patterns and community composition among prokaryotic, eukaryotic, and chloroplastic communities, highlighting the importance of multi-domain analyses in plastisphere research. Functional predictions suggest potential roles of prokaryotic communities in biogeochemical cycling and possible pathogenicity, highlighting the ecological and public health implications of plastisphere formation. This study provides valuable insights into the dynamics of microbial colonization across domains on marine plastics and enhances our understanding of how these anthropogenic substrates influence microbial ecology in marine ecosystems.