Non-metric multidimensional scaling (nMDS) ordinations of sediment and LDPE microplastic-associated bacterial communities in sediment microcosms. The ordinations were derived from a Bray-Curtis resemblance matrix calculated from square-root-transformed terminal restriction fragment (T-RF) relative abundance data. Data are shown for bacterial communities a) on LDPE fragments (stress = 0.16) and b) within sediments (stress = 0.13). Labels correspond to samples taken over time [immediately (Imm.), and after 6 hours, and on days (D) 1, 2, 4, 7 and 14)] from microcosms containing coastal marine sediments from three sites (SP1, SP2 and WB, as indicated). Similarity thresholds (%) are based on group-average clustering. Arrows indicate the temporal trajectory of bacterial community succession on LDPE surfaces.