Principal coordinate analysis revealed a clustering pattern mainly influenced by the material of the straws (p<0.01, PERMANOVA) (Figure ), suggesting the degradability (Figure ) of the straws selected for distinct microbial communities. The straws that degraded had unique microbial communities based on material type (i.e., CDA, PHA, and paper). In contrast, the PLA and PP straws, which did not measurably degrade, had similar community structures despite having vastly different material types (i.e., polyester vs. polyolefin). This result suggests these materials only provided surfaces for the colonization of microorganisms rather than substrates for metabolism, an observation consistent with our previous findings. Microbial community composition analysis at the family level revealed detailed differences between the adherent communities on the straws and the microbial communities in seawater (Figure ). Specifically, the relative abundances of Cellvibrionaceae, Microtrichaceae, and