Biosciences, Faculty of Health and Life Sciences, University of Exeter, Exeter EX4 4QD, UK.
Biosciences, Faculty of Health and Life Sciences, University of Exeter, Exeter EX4 4QD, UK; Galapagos Conservation Trust, 7-14 Great Dover Street, London SE1 4YR, UK.
Sci Total Environ. 2024 May 1;923:171428. doi: 10.1016/j.scitotenv.2024.171428. Epub 2024 Mar 2.
Plastic pollution in the oceans is increasing, yet most global sea surface data is collected using plankton nets which limits our knowledge of the smaller and more bioaccessible size fraction of microplastics (<5 mm). We sampled the biodiverse coastal waters of the Galapagos Island of San Cristobal, comparing two different microplastic sampling methodologies; 1 l whole seawater grab samples filtered to 1.2 μm and sea surface plankton tows with a net mesh size of 200 μm. Our data reveal high concentrations of microplastics in Galapagos coastal waters surrounding the urban area, averaging 11.5 ± 1.48 particles l, with a four-order of magnitude increase in microplastic abundance observed using grab sampling compared with 200 μm plankton nets. This increase was greater when including anthropogenic cellulose particles, averaging 19.8 ± 1.86 particles l. Microplastic and anthropogenic cellulose particles smaller than 200 μm comprised 44 % of the particles from grab samples, suggesting previous estimates of microplastic pollution based on plankton nets likely miss and therefore underestimate these smaller particles. The particle characteristics and distribution of these smaller particles points strongly to a local input of cellulosic fibres in addition to the microplastic particles transported longer distances via the Humbolt current found across the surface seawater of the Galapagos. Improving our understanding of particle characteristics and distributions to highlight likely local sources will facilitate the development of local mitigation and management plans to reduce the input and impacts of microplastics to marine species, not just in the Galapagos but globally.
海洋中的塑料污染正在增加，但大多数全球海面数据是使用浮游生物网收集的，这限制了我们对更小、更具有生物可利用性的微塑料（<5 毫米）的了解。我们对加拉帕戈斯群岛圣克里斯托瓦尔岛的生物多样性沿海水域进行了采样，比较了两种不同的微塑料采样方法：1 升全海水抓取样品过滤至 1.2μm 和海面浮游生物拖网，网目尺寸为 200μm。我们的数据显示，加拉帕戈斯沿海城市周围海域的微塑料浓度很高，平均为 11.5±1.48 个颗粒/升，与使用抓取采样相比，微塑料丰度增加了四个数量级浮游生物网。当包括人为纤维素颗粒时，这一增长更为明显，平均为 19.8±1.86 个颗粒/升。小于 200μm 的微塑料和人为纤维素颗粒占抓取样品中颗粒的 44%，这表明以前基于浮游生物网的微塑料污染估计可能会遗漏这些较小的颗粒，因此低估了这些颗粒。这些较小颗粒的特征和分布强烈表明，除了通过 Humbolt 洋流从更远的地方输送而来的微塑料颗粒外，还有纤维素纤维的本地输入。为了更好地了解颗粒特征和分布，以突出可能的本地来源，这将有助于制定当地的缓解和管理计划，以减少微塑料对海洋物种的输入和影响，不仅在加拉帕戈斯群岛，而且在全球范围内。
