Abstract：
Pollution of the natural environment by microplastics has become a global issue in ecosystems as it poses a potential long-term threat to biota. Microplastics can accrue in high abundances in sediments of aquatic ecosystems while also contaminating pelagic filter feeders, which could transfer pollutants up trophic webs. We assess the abundance and distribution of microplastics in benthic sediments and Cladocera taxa in a subtropical Austral reservoir using a combination of geospatial techniques, physicochemical analyses, diversity indices, and multivariate statistics between two seasons (i.e., hot-wet and cool-dry). We found particularly high densities of microplastics during the cool-dry season for both sediments (mean 224.1 vs. 189 particles kg-1 dry weight) and Cladocera taxa (0.3 particles per individual). Cladocera microplastic shapes were dominated by fibers with high densities of the transparent color scheme. Pearson correlation results indicated that sediment microplastic abundances were negatively correlated with chlorophyll-a concentration, temperature, and resistivity, whereas they were positively correlated with pH and salinity during the hot-wet season, with no variables significant in the cool-dry season. Cladocera microplastic abundances were positively correlated with conductivity and salinity during the cool-dry season, but no variables in the hot-wet season. These findings provide insights into the role of reservoirs as microplastic retention sites and the potential for uptake and transfer from lower trophic groups. These insights can be used to strengthen future monitoring and intervention strategies. Integr Environ Assess Manag 2024;1-15. © 2024 SETAC.
摘要：
微塑料对自然环境的污染已成为生态系统中的一个全球性问题，因为它对生物群构成了潜在的长期威胁。微塑料可以在水生生态系统的沉积物中大量积累，同时还会污染中上层滤食动物，可以将污染物转移到营养网上。我们使用地理空间技术的组合评估了亚热带南方储层底栖沉积物和Cladocera类群中微塑料的丰度和分布，物理化学分析,多样性指数，和两个季节之间的多变量统计(即，热湿和冷干)。在凉爽干燥的季节，我们发现两种沉积物的微塑料密度特别高（平均224.1与189个颗粒kg-1干重）和Cladocera类群（每个个体0.3个颗粒）。Cladocera微塑性形状以具有高密度透明配色方案的纤维为主。Pearson相关结果表明,沉积物微塑性丰度与叶绿素a浓度呈负相关,温度,和电阻率，在湿热季节，它们与pH和盐度呈正相关，在凉爽干燥的季节没有显著的变量。在凉爽干燥的季节，Cladocera微塑料丰度与电导率和盐度呈正相关，但在湿热季节没有变数。这些发现提供了有关储库作为微塑料保留位点的作用以及从较低营养类群吸收和转移的潜力的见解。这些见解可用于加强未来的监测和干预策略。Integr环境评估管理2024；1-15。©2024SETAC。
