Van Colen Carl, Moereels Lieke, Vanhove Brecht, Vrielinck Henk, Moens Tom
Ghent University, Marine Biology Research Group, Krijgslaan 281/S8, B-9000 Ghent, Belgium.
Ghent University, Marine Biology Research Group, Krijgslaan 281/S8, B-9000 Ghent, Belgium.
Environ Pollut. 2021 Apr 1;274:115825. doi: 10.1016/j.envpol.2020.115825. Epub 2020 Nov 18.
The distinct spatial variability in microplastic concentrations between marine regions and habitats calls for a better understanding about the transport pathways of this omnipresent pollutant in the marine environment. This study provides empirical evidence that a sessile filter feeder, the Blue mussel M. edulis, accelerates microplastic deposition by aggregating them into sinking particulate faeces and pseudofaeces. After settling to the seafloor, the bioturbation of benthic fauna quickly buries these microplastics. Collectively, these results suggest that if such biologically-mediated benthic-pelagic coupling would be integrated into hydrodynamic transport models, the spatial variability and source-sink dynamics of microplastics would be better understood. It is proposed that microplastic pollution is monitored through sampling that takes into account faeces and pseudofaeces underneath filter feeders. The implications of this detrital pathway for microplastic transfer to the seafloor, and the role of shellfish mariculture in this process, are discussed. Studies that consider filter feeders and benthic communities from other regions, and during different seasons, are needed to validate the proposed biological pump mechanism across space and time.
海洋区域和栖息地之间微塑料浓度存在明显的空间变异性，这就需要更好地了解这种普遍存在的污染物在海洋环境中的传输途径。本研究提供了实证证据，表明一种固着滤食性动物——蓝贻贝（Mytilus edulis），通过将微塑料聚集到下沉的颗粒粪便和假粪便中，加速了微塑料的沉积。沉降到海底后，底栖动物的生物扰动会迅速掩埋这些微塑料。总体而言，这些结果表明，如果将这种生物介导的底栖-水层耦合纳入水动力传输模型，将能更好地理解微塑料的空间变异性和源汇动态。建议通过考虑滤食性动物下方粪便和假粪便的采样来监测微塑料污染。本文讨论了这条碎屑途径对微塑料向海底转移的影响，以及贝类养殖在这一过程中的作用。需要开展研究，考虑其他区域以及不同季节的滤食性动物和底栖生物群落，以验证所提出的生物泵机制在空间和时间上的有效性。
