摘要

在海洋环境中，大多数双壳类物种的繁殖基于外部受精。因此，配子和年轻阶段面临许多威胁，包括暴露于塑料废物，这些废物占海洋中80％以上的碎片。最近，有关纳米塑料在海洋中存在的证据已经产生，从而激发了对其对海洋生物影响的新研究。由于没有关于其环境浓度的信息，我们使用聚苯乙烯颗粒进行剂量反应暴露实验，以评估微/纳米塑性毒性的程度。在太平洋牡蛎的三个关键生殖步骤（受精，胚胎发生和变态）上评估了不同大小和功能化的聚苯乙烯（平原2-μm，500-nm和50-nm; COOH-50nm和NH2-50nm）的影响（ Crassostrea gigas）。纳米塑料诱导了受精成功和胚胎幼虫发育的显着减少，其中许多畸形直至总发育停滞。 NH2-50珠子对两种配子（EC50 =4.9μg/ mL）和胚胎（EC50 =0.15μg/ mL）具有最强的毒性，显示出功能化依赖性毒性。没有记录普通微塑料的影响。这些结果强调，暴露于纳米塑料可能对牡蛎的浮游阶段产生有害影响，可能与生物膜相互作用并导致细胞/遗传毒性，并可能对其繁殖成功产生严重后果。

In the marine environment, most bivalve species base their reproduction on external fertilization. Hence, gametes and young stages face many threats, including exposure to plastic wastes which represent more than 80% of the debris in the oceans. Recently, evidence has been produced on the presence of nanoplastics in oceans, thus motivating new studies of their impacts on marine life. Because no information is available about their environmental concentrations, we performed dose-response exposure experiments with polystyrene particles to assess the extent of micro/nanoplastic toxicity. Effects of polystyrene with different sizes and functionalizations (plain 2-μm, 500-nm and 50-nm; COOH-50 nm and NH2-50 nm) were assessed on three key reproductive steps (fertilization, embryogenesis and metamorphosis) of Pacific oysters (Crassostrea gigas). Nanoplastics induced a significant decrease in fertilization success and in embryo-larval development with numerous malformations up to total developmental arrest. The NH2-50 beads had the strongest toxicity to both gametes (EC50 = 4.9 μg/mL) and embryos (EC50 = 0.15 μg/mL), showing functionalization-dependent toxicity. No effects of plain microplastics were recorded. These results highlight that exposures to nanoplastics may have deleterious effects on planktonic stages of oysters, presumably interacting with biological membranes and causing cyto/genotoxicity with potentially drastic consequences for their reproductive success.

https://www.ncbi.nlm.nih.gov/pubmed/30118910