This study investigates microbial colonization of plastics in Caribbean coastal waters. We deployed five polymer types, on set with a mild UV-pretreatment and one set without UV-pretreatment, for 4.5 months in the water column and sediment at two locations, and analyzed the epiplastic biofilms with 16S rRNA gene sequencing. While a significant influence of location and habitat was apparent, we could not detect notable effects related to polymer type or UV-pretreatment on microbial community composition. Nevertheless, potential plastic and hydrocarbon degraders constituted up to 43 % of sequences from epiplastic biofilms, suggesting an affinity for plastic. Indeed, utilizing