Gallitelli L, Cera A, Scalici M, Sodo A, Di Gioacchino M, Luzi B, Hortas F, Green A J, Coccia C
Department of Sciences, University of Rome Tre, Rome, Italy.
Institute of Freshwater Biology, Nagano University, 1088 Komaki, Ueda, Nagano 386-0031, Japan.
Sci Total Environ. 2024 Dec 1;954:176707. doi: 10.1016/j.scitotenv.2024.176707. Epub 2024 Oct 8.
Wetlands provide numerous ecosystem services including freshwater purification. Nonetheless, their functionality is continuously impacted by many pollutants. Plastics are considered as an emerging threat for these ecosystems, but only recently have studies began to focus on plastic and microplastic (MP) contamination in wetlands, especially in biota. This study aims to investigate the abundance of MPs in two ubiquitous aquatic insect taxa (i.e. Corixidae (Hemiptera) and Chironomidae (Diptera)) collected in twelve zones within Mediterranean wetlands belonging to three basins located in Andalusia (south-west Spain). We compared MP contamination across basins and tested the proximity to landfills and presence of colonial waterbirds [i.e. white storks (Ciconia ciconia) and gulls (Larus michahellis and L. fuscus)] on MP abundance in aquatic insects. We also performed stable isotope analyses of nitrogen and carbon (δN and δC) to evaluate the potential association between MP abundance and isotopic values. We detected 571 suspected MPs (mostly blue fibers) in insects of different developmental stages (i.e., larvae, pupae, nymphs and adults). Polyesters and polypropylene were the most frequent polymers detected. The generalized linear mixed models indicated that MP abundance decreased with increasing distance from landfills; but it also increased in sites with birds that fed on landfills and roost in wetlands. When controlling for landfill effects, sites in the smallest basin (Guadalete) had lower MP contamination than those in Odiel-Tinto and the much larger (>15×) Guadalquivir. Moreover, we found a negative association between MPs items/g (or mean MPs) and N isotopes in adult corixids. Our findings showed that MP pollution is present in all the study areas, including strictly protected wetlands. The use of aquatic insects for biomonitoring of MP pollution can help identify priority areas for management actions to mitigate plastic pollution.
湿地提供了包括淡水净化在内的众多生态系统服务。尽管如此，它们的功能不断受到多种污染物的影响。塑料被认为是这些生态系统面临的一种新威胁，但直到最近，研究才开始关注湿地，尤其是生物群中的塑料和微塑料（MP）污染。本研究旨在调查在地中海湿地的12个区域采集的两种常见水生昆虫类群（即划蝽科（半翅目）和摇蚊科（双翅目））中的微塑料丰度，这些湿地属于位于西班牙西南部安达卢西亚的三个流域。我们比较了各流域间的微塑料污染情况，并测试了与垃圾填埋场的距离以及殖民水鸟（即白鹳（白鹳）和鸥类（黑背鸥和棕头鸥））的存在对水生昆虫微塑料丰度的影响。我们还进行了氮和碳的稳定同位素分析（δN和δC），以评估微塑料丰度与同位素值之间的潜在关联。我们在不同发育阶段（即幼虫、蛹、若虫和成虫）的昆虫中检测到571个疑似微塑料（主要是蓝色纤维）。检测到的最常见聚合物是聚酯和聚丙烯。广义线性混合模型表明，微塑料丰度随着与垃圾填埋场距离的增加而降低；但在有以垃圾填埋场为食并在湿地栖息的鸟类的地点，微塑料丰度也会增加。在控制垃圾填埋场影响后，最小流域（瓜达莱特）的地点的微塑料污染低于奥迪埃尔 - 廷托流域和大得多（>15倍）的瓜达尔基维尔河流域的地点。此外，我们发现成年划蝽中每克微塑料数量（或平均微塑料）与氮同位素之间存在负相关。我们的研究结果表明，微塑料污染存在于所有研究区域，包括严格保护的湿地。利用水生昆虫对微塑料污染进行生物监测有助于确定管理行动的优先区域，以减轻塑料污染。
