A spatio-temporal analysis of marine diatom communities associated with pristine and aged plastics

Complex microbial communities colonize plastic substrates over time, strongly influencing their fate and potential impacts on marine ecosystems. Among the first colonizers, diatoms play an important role in the development of this ‘plastiphere’. We investigated 936 biofouling samples and the factors influencing diatom communities associated with plastic colonization. These factors included geographic location (up to 800 km apart), duration of substrate submersion (1 to 52 weeks), plastics (5 polymer types) and impact of artificial ageing with UV light. Diatom communities colonizing plastic debris were primarily determined by their geographic location and submersion time, with the strongest changes occurring within two weeks of submersion. Several taxa were identified as early colonizers (e.g. Cylindrotheca, Navicula and Nitzschia spp.) with known strong adhesion capabilities. To a lesser extent, plastic-type and UV-ageing significantly affected community composition, with 14 taxa showing substrate-specificity. This study highlights the role of plastics types-state for colonization in the ocean.

复杂的微生物群落会随时间在塑料基材表面定殖，显著影响塑料的归宿及其对海洋生态系统的潜在影响。作为首批定殖者之一，硅藻（diatoms）在这一“塑料圈（plastiphere）”的形成过程中发挥着重要作用。本研究共分析936份生物污损（biofouling）样本，探究与塑料定殖相关的硅藻群落及其影响因素。这些影响因素涵盖地理位置（样本间最大间距可达800公里）、基材浸没时长（1至52周）、塑料类型（共5种聚合物基材）以及紫外线人工老化的作用。定殖于塑料碎屑的硅藻群落主要受地理位置与浸没时长调控，群落结构的最显著变化发生在浸没后的两周内。研究鉴定出多个具备较强附着能力的早期定殖分类群（taxa），例如圆柱丝藻属（Cylindrotheca）、舟形藻属（Navicula）与菱形藻属（Nitzschia）的相关物种。在较小程度上，塑料类型与紫外线老化也会显著影响群落组成，共有14个分类群表现出基材特异性。本研究强调了海洋塑料的类型与状态在定殖过程中的关键作用。