Phycisphaeraceae had the greatest relative abundance on the coated (14%) and uncoated (17%) paper straws. Compared with seawater, the relative abundance of Cellvibrionaceae, Microtrichaceae, and Cyclobacteriaceae also markedly increased on PHA straws. For the PLA and PP straws, microbial taxa of Microtrichaceae, Rhizobiaceae, and Saprospiraceae were enriched. Most of the taxa that exhibited significant changes in relative abundance compared to