State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai, 200062, China; Hainan Institute, East China Normal University, Sanya, 572025, China; Plastic Marine Debris Research Center, East China Normal University, Shanghai, 200241, China; Regional Training and Research Center on Plastic Marine Debris and Microplastics, IOC-UNESCO, Shanghai, 200241, China.
Department of Marine Science, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand.
Mar Environ Res. 2024 May;197:106455. doi: 10.1016/j.marenvres.2024.106455. Epub 2024 Mar 15.
Microplastics have been reported to be present in zooplankton, yet questions persist regarding their fate and dynamics within biota. We selected the commercial mysid shrimp, Mesopodopsis orientalis, as the focal zooplankton for this study due to their crucial role in our study area, the Inner Gulf of Thailand in January 2022. We investigated the presence of microplastics in mysid bodies and fecal pellets, examining both attached microplastics on external body parts and those ingested. In addition, we conducted microplastic feeding experiments, exposing mysids to various treatments of microplastics. The results of the field investigation indicate that mysids exhibited an average of 0.12 ± 0.03 microplastic items/mysid from whole-body samples. The shape, type, and color of microplastics found in mysids were similar to those present in seawater, with blue PET microfibers being the most prevalent. Our observations on live mysids revealed that microplastics were acquired through ingestion and adherence to appendages and exoskeletons. Microplastics were observed in mysid's fecal pellets at 0.09 ± 0.03 items/mysid, while microplastics adhering to the mysid's body and appendages were observed at 0.10 ± 0.04 items/mysid. The sizes of microplastics extracted from preserved mysids ranged from 58 μm to 4669 μm, with median of 507 μm. The laboratory experiments revealed that the presence of microalgae enhanced microplastic ingestion in mysids; microplastics incubated with a cyanobacterium, Oscillatoria sp., and diatom Navicula sp. significantly increased the number of microplastic particles ingested by mysids. This study showed that microplastics can be more ingested in mysids, especially when food items are present. Microplastic fate in these animals may involve expulsion into the environment or adherence, potentially facilitating their transfer up the marine food web.
微塑料已被报道存在于浮游动物中，但关于其在生物体内的命运和动态仍存在疑问。我们选择商业性糠虾，东方真糠虾作为本研究的焦点浮游动物，因为它们在我们的研究区域——泰国湾内部，于 2022 年 1 月具有重要作用。我们研究了糠虾体内和粪便颗粒中微塑料的存在情况，检查了外部身体部位附着的微塑料和摄入的微塑料。此外，我们还进行了微塑料摄食实验，使糠虾暴露于不同的微塑料处理中。野外调查结果表明，糠虾全身样本中平均每只含有 0.12±0.03 个微塑料颗粒。在糠虾体内发现的微塑料的形状、类型和颜色与海水中的相似，其中蓝色 PET 微纤维最为常见。我们对活体糠虾的观察表明，微塑料是通过摄入和附着在附肢和外骨骼上而获得的。在 0.09±0.03 个/糠虾的粪便颗粒中观察到微塑料，而在 0.10±0.04 个/糠虾的糠虾体和附肢上观察到微塑料。从保存的糠虾中提取的微塑料的尺寸范围为 58μm 至 4669μm，中位数为 507μm。实验室实验表明，微藻的存在促进了糠虾对微塑料的摄食；与蓝藻 Oscillatoria sp. 和硅藻 Navicula sp. 一起孵育的微塑料显著增加了糠虾摄入的微塑料颗粒数量。本研究表明，微塑料在糠虾体内的摄食量可能会增加，尤其是在存在食物的情况下。这些动物体内的微塑料命运可能涉及到被排放到环境中或附着在体内，从而有可能促进它们在海洋食物网中的转移。
