Jaouani Rihab, Mouneyrac Catherine, Châtel Amélie, Amiard Frédéric, Dellali Mohamed, Beyrem Hamouda, Michelet Alexandre, Lagarde Fabienne
Institut des Molécules et Matériaux du Mans (IMMM, UMR CNRS 6283), Le Mans Université, Avenue Olivier Messiaen, F-72085 Le Mans, France; Laboratoire Biologie des Organismes, Stress, Santé, Environnement (BIOSSE), Université Catholique de l'Ouest, F-49000 Angers, France; Laboratoire de biosurveillance de l'environnement, Faculté des Sciences de Bizerte, Zarzouna 7021, Tunisie.
Laboratoire Biologie des Organismes, Stress, Santé, Environnement (BIOSSE), Université Catholique de l'Ouest, F-49000 Angers, France.
Sci Total Environ. 2022 Sep 10;838(Pt 4):156519. doi: 10.1016/j.scitotenv.2022.156519. Epub 2022 Jun 8.
Plastics pollution in marine environment has become an issue of increasing scientific concern. This work aims to study the temporal and spatial distribution of plastics in sediments from three different Tunisian ecosystems; Rimel Beach, Bizerta lagoon and Ichkeul lake. Sediment sampling was conducted in surface (2 cm) and depth (15 cm) during spring, summer and winter. Plastics debris were separated by size fractions: macro (>5 mm), meso (1-5 mm) and microplastics (<1 mm) to optimize the time necessary for their characterisation. Macroplastics and mesoplastics were identified using an IR Attenuated total reflectance (ATR) and microplastics with Imaging Fourier transform infrared spectroscopy (FTIR) spectroscopy after an optimized extraction protocol. Results indicate that, the lowest contamination degree with macroplastics was recorded in Ichkeul lake, 2 macro debris/m (marine protected area, national parc of Ichkeul). Mesoparticles were only detected in lagoon of Bizerte in large quantities (4900 item/kg of sediment in surface and 680 item/kg of sediment in depth) and were identified principally as paint products. For microplastics, the repartition was quite homogeneous between the three sites with an average abundance was 130.55 ± 65.61 items/kg for all seasons. The variations of microplastics abundances on the three sites could not be clearly related to the seasons. Whereas the polymer characterisation in the surface and depth sediments of the three studied areas were principally due to eight types of polymers (PVC, PET, PP, PE PS, Polyamide (PA) and polymeric methyl methacrylate (PMMA)) as reported in many other studies, surprisingly all MPs recovered in the study were smaller than 300 μm, >70 % being fragments. This study brings new results as regards to the state of plastic contamination in Tunisian coast and shows the importance of investigating different ecosystems in such studies.
海洋环境中的塑料污染已成为一个日益受到科学界关注的问题。这项工作旨在研究来自突尼斯三个不同生态系统（里梅尔海滩、比塞大泻湖和伊克克乌尔湖）沉积物中塑料的时空分布。在春季、夏季和冬季对表层（2厘米）和深层（15厘米）沉积物进行采样。塑料碎片按尺寸分级分离：大型（>5毫米）、中型（1 - 5毫米）和微塑料（<1毫米），以优化其表征所需时间。大型塑料和中型塑料使用红外衰减全反射（ATR）进行鉴定，微塑料在经过优化的提取方案后，使用成像傅里叶变换红外光谱（FTIR）光谱进行鉴定。结果表明，伊克克乌尔湖记录的大型塑料污染程度最低，为2个大型碎片/米（海洋保护区，伊克克乌尔国家公园）。中型颗粒仅在比塞大泻湖中大量检测到（表层沉积物中为4900个/千克，深层沉积物中为680个/千克），主要鉴定为涂料产品。对于微塑料，三个地点的分布相当均匀，所有季节的平均丰度为130.55±65.61个/千克。三个地点微塑料丰度的变化与季节没有明显关联。尽管正如许多其他研究报道的那样，三个研究区域表层和深层沉积物中的聚合物表征主要归因于八种聚合物（聚氯乙烯、聚对苯二甲酸乙二酯、聚丙烯、聚乙烯、聚苯乙烯、聚酰胺（PA）和聚甲基丙烯酸甲酯（PMMA）），但令人惊讶的是，该研究中回收的所有微塑料都小于300微米，超过70%为碎片。这项研究带来了关于突尼斯海岸塑料污染状况的新结果，并表明在这类研究中调查不同生态系统的重要性。
