Wazne Mohammad, Mermillod-Blondin Florian, Vallier Manon, Hervant Frédéric, Dumet Adeline, Nel Holly A, Kukkola Anna, Krause Stefan, Simon Laurent
Université de Lyon, Université Claude Bernard Lyon 1, CNRS, ENTPE, UMR 5023 LEHNA, F 69622 Villeurbanne, France.
School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K.
Environ Sci Technol. 2023 Feb 28;57(8):3042-3052. doi: 10.1021/acs.est.2c05662. Epub 2023 Feb 15.
While microplastic transport, fate, and effects have been a focus of studies globally, the consequences of their presence on ecosystem functioning have not received the same attention. With increasing evidence of the accumulation of microplastics at sediment-water interfaces there is a need to assess their impacts on ecosystem engineers, also known as bioturbators, which have direct and indirect effects on ecosystem health. This study investigated the impact of microplastics on the bioturbator alongside any effects on the biogeochemical processes at the sediment-water interface. Bioturbators were exposed to four sediment microplastic concentrations: 0, 700, 7000, and 70000 particles kg sediment dry weight. Though no mortality was present, a significant response to oxidative stress was detected in worms after exposure to medium microplastic concentration (7000 particles kg sediment dry weight). This was accompanied by a reduction in worm bioturbation activities assessed by their ability to rework sediment and to stimulate exchange water fluxes at the sediment-water interface. Consequently, the contributions of tubificid worms on organic matter mineralization and nutrient fluxes were significantly reduced in the presence of microplastics. This study demonstrated that environmentally realistic microplastic concentrations had an impact on biogeochemical processes at the sediment-water interface by reducing the bioturbation activities of tubificid worms.
虽然微塑料的迁移、归宿和影响一直是全球研究的重点，但其存在对生态系统功能的影响尚未得到同等程度的关注。随着微塑料在沉积物 - 水界面积累的证据越来越多，有必要评估它们对生态系统工程师（也称为生物扰动者）的影响，这些生物扰动者对生态系统健康有直接和间接影响。本研究调查了微塑料对生物扰动者的影响以及对沉积物 - 水界面生物地球化学过程的任何影响。生物扰动者暴露于四种沉积物微塑料浓度：0、700、7000和70000个颗粒/千克沉积物干重。虽然没有出现死亡情况，但在暴露于中等微塑料浓度（7000个颗粒/千克沉积物干重）后，检测到蠕虫对氧化应激有显著反应。这伴随着通过蠕虫改造沉积物的能力以及刺激沉积物 - 水界面水交换通量来评估的蠕虫生物扰动活动的减少。因此，在存在微塑料的情况下，颤蚓对有机质矿化和养分通量的贡献显著降低。这项研究表明，环境现实中的微塑料浓度通过降低颤蚓的生物扰动活动，对沉积物 - 水界面的生物地球化学过程产生了影响。
