Plastic pollution has become a major environmental and societal concern in the last decade. From larger debris to microplastics (MP), this pollution is ubiquitous and particularly affects aquatic ecosystems. MP can be directly or inadvertently ingested by organisms, transferred along the trophic chain, and sometimes translocated into tissues. However, the impacts of such MP exposure on organisms’ biological functions are yet to be fully understood. Here, we used a multi-diagnostic approach at multiple levels of biological organization (from atoms to organisms) to determine how MP affect the biology of a marine fish, the gilthead seabream, Sparus aurata. We exposed juvenile seabreams for 35 days to spherical 10–20 µm polyethylene primary MP through food (Artemia salina pre-exposed to MP) at a concentration of 5 ± 1 µg of MP per gram of fish per day. MP-exposed fish experienced higher mortality, increased abundance of several brain and liver primary metabolites, hepatic and intestinal histological defects, higher assimilation of an essential element (Zn), and lower assimilation of a non-essential element (Ag). In contrast, growth and muscle C/N isotopic profiles were similar between control and MP-exposed fish, while variable patterns were observed for the intestinal microbiome. This comprehensive analysis of biological responses to MP exposure reveals how MP ingestion can cause negligible to profound effects in a fish species and contributes towards a better understanding of the causal mechanisms of its toxicity.

在过去十年中，塑料污染已成为主要的环境和社会问题。从较大的碎片到微塑料 (MP)，这种污染无处不在，尤其会影响水生生态系统。MP 可以直接或无意中被生物体摄取，沿营养链转移，有时还转移到组织中。然而，这种 MP 暴露对生物体生物功能的影响尚未完全了解。在这里，我们在生物组织的多个层面（从原子到生物体）使用了多诊断方法来确定 MP 如何影响海鱼、金头鲷和Sparus aurata的生物学. 我们通过食物（卤虫预先暴露于 MP）将幼鲷暴露于球形 10–20 µm 聚乙烯初级 MP 中 35 天，浓度为每天每克鱼 5 ± 1 µg MP。暴露于 MP 的鱼经历了更高的死亡率、几种脑和肝脏初级代谢物的丰度增加、肝脏和肠道组织学缺陷、必需元素 (Zn) 的更高同化和非必需元素 (Ag) 的更低同化。相比之下，对照鱼和暴露于 MP 的鱼的生长和肌肉 C/N 同位素分布相似，而肠道微生物组观察到了不同的模式。