Light-Matter Interactions for Quantum Technologies Unit, Okinawa Institute of Science and Technology, Onna, Okinawa 904-0495, Japan; Marine Genomics Unit, Okinawa Institute of Science and Technology, Onna, Okinawa 904-0495, Japan.
Light-Matter Interactions for Quantum Technologies Unit, Okinawa Institute of Science and Technology, Onna, Okinawa 904-0495, Japan.
Sci Total Environ. 2021 Mar 15;760:143927. doi: 10.1016/j.scitotenv.2020.143927. Epub 2020 Dec 13.
Marine plastic debris is widely recognized as a global environmental issue. Small microplastic particles, with an upper size limit of 20 μm, have been identified as having the highest potential for causing damage to marine ecosystems. Having accurate methods for quantifying the abundance of such particles in a natural environment is essential for defining the extent of the problem they pose. Using an optical micro-Raman tweezers setup, we have identified the composition of particles trapped in marine aggregates collected from the coastal surface waters around the subtropical island of Okinawa. Chemical composition analysis at the single-particle level indicates dominance by low-density polyethylene, which accounted for 75% of the small microplastics analysed. The smallest microplastics identified were (2.53 ± 0.85) μm polystyrene. Our results show the occurrence of plastics at all test sites, with the highest concentration in areas with high human activities. We also observed additional Raman peaks on the plastics spectrum with decreasing debris size which could be related to structural modification due to weathering or embedding in organic matter. By identifying small microplastics at the single-particle level, we obtain some indication on their dispersion in the ocean which could be useful for future studies on their potential impact on marine biodiversity.
海洋塑料碎片被广泛认为是一个全球性的环境问题。已确定粒径上限为 20μm 的小微型塑料颗粒具有对海洋生态系统造成损害的最大潜在风险。拥有准确的方法来量化自然环境中此类颗粒的丰度，对于确定它们所构成问题的严重程度至关重要。我们使用光学微拉曼镊子装置，鉴定了从冲绳亚热带岛屿周围沿海表层水中采集的海洋聚集体中捕获的颗粒的组成。对单个颗粒进行的化学成分分析表明，低密度聚乙烯占主导地位，占分析的小微型塑料的 75%。鉴定出的最小微型塑料是（2.53±0.85）μm 的聚苯乙烯。我们的结果表明，所有测试点都存在塑料，在人类活动较多的区域浓度最高。我们还观察到随着碎片尺寸的减小，塑料光谱上出现了其他拉曼峰，这可能与由于风化或嵌入有机物而导致的结构修饰有关。通过在单个颗粒水平上鉴定小微型塑料，我们获得了一些关于它们在海洋中分散的信息，这对于未来研究它们对海洋生物多样性的潜在影响可能会很有用。
