Microplastics primarily provide habitats for benthic microalgae in Fujian coastal waters of China

Microplastics (MPs) serve as habitats and vectors for microalgae-termed epimicroplastic microalgae (EMP-MA). This study analyzed the community structure and diversity of EMP-MA in three bays of Fujian Province, and compared them with planktonic microalgae (PM) communities. Results showed both EMP-MA and PM communities mainly comprised diatoms and dinoflagellates, but differed significantly. Specifically, the relative abundance of benthic microalgae in EMP-MA communities was significantly higher than that in PM communities, with all dominant species of EMP-MA communities being benthic species. These results meant that MPs primarily provide habitats for benthic microalgae and may expand their spatial distribution. In addition, environmental variables exerted weaker influences on EMP-MA than on PM, which might be attributed to the buffering effects of biofilm. This study holds significance for deepening the understanding of the vertical distribution dynamics of marine microalgae and the effects of MPs on marine biological processes.