Department of Global Ecology, Carnegie Institution for Science, Stanford, CA, 94305, USA.
Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, 94305, USA.
Environ Pollut. 2019 Jun;249:512-517. doi: 10.1016/j.envpol.2019.02.100. Epub 2019 Mar 6.
Microplastics are emerging contaminants in the marine environment. They enter the ocean in a variety of sizes and shapes, with plastic microfiber being the prevalent form in seawater and in the guts of biota. Most of the laboratory experiments on microplastics has been performed with spheres, so knowledge on the interactions of microfibers and marine organisms is limited. In this study we examined the ingestion of microfibers by the sea anemone Aiptasia pallida using three different types of polymers: nylon, polyester and polypropylene. The polymers were offered to both symbiotic (with algal symbionts) and bleached (without algal symbionts) anemones. The polymers were introduced either alone or mixed with brine shrimp homogenate. We observed a higher percentage of nylon ingestion compared to the other polymers when plastic was offered in the absence of shrimp. In contrast, we observed over 80% of the anemones taking up all types of polymers when the plastics were offered in the presence of shrimp. Retention time differed significantly between symbiotic and bleached anemones with faster egestion in symbiotic anemones. Our results suggest that ingestion of microfibers by sea anemones is dependent both on the type of polymers and on the presence of chemical cues of prey in seawater. The decreased ability of bleached anemones to reject plastic microfiber indicates that the susceptibility of anthozoans to plastic pollution is exacerbated by previous exposure to other stressors. This is particularly concerning given that coral reef ecosystems are facing increases in the frequency and intensity of bleaching events due to ocean warming.
微塑料是海洋环境中的新兴污染物。它们以各种大小和形状进入海洋，其中塑料微纤维是海水中和生物体内最常见的形式。大多数关于微塑料的实验室实验都是用球体进行的，因此对微纤维与海洋生物相互作用的知识有限。在这项研究中，我们使用三种不同的聚合物（尼龙、聚酯和聚丙烯）研究了海葵 Aiptasia pallida 对微纤维的摄取：尼龙、聚酯和聚丙烯。将聚合物提供给共生（有藻类共生体）和去共生（没有藻类共生体）的海葵。聚合物要么单独提供，要么与丰年虾匀浆混合提供。当没有虾提供时，与其他聚合物相比，我们观察到尼龙的摄取率更高。相比之下，当塑料在有虾的情况下提供时，我们观察到超过 80%的海葵吸收所有类型的聚合物。共生和去共生海葵之间的滞留时间差异显著，共生海葵的排出速度更快。我们的结果表明，海葵对微纤维的摄取既取决于聚合物的类型，也取决于海水中猎物化学线索的存在。去共生海葵对塑料微纤维的排斥能力下降表明，珊瑚虫对塑料污染的敏感性因先前暴露于其他胁迫而加剧。鉴于珊瑚礁生态系统因海洋变暖而面临着白化事件频率和强度的增加，这尤其令人担忧。
