Microfibers are now ubiquitous in the environment largely due to the widespread use of natural and synthetic textiles. Many enter aquatic systems through wastewater treatment plant (WWTP) effluent, surface water runoff, and atmospheric deposition, where they persist and may be ingested by filter-feeding organisms. In addition to causing physical damage (e.g., digestive and respiratory obstructions), microfibers are often carriers of chemical pollutants that may also harm biota. This exploratory study aimed to determine whether freshwater mussel (Margaritifera margaritifera L.) microfiber content varied between two rural tributaries of the Saint John River, whether microfiber content was related to WWTP discharge points or potential diffuse microfiber sources, and whether mussel size was associated with microfiber content. Mussels were collected both upstream and downstream of five WWTP discharge points and at 11 other points along two rivers within rural watersheds of maritime Canada. Microfiber content differed significantly between the two rivers; however, no trends were observed in microfiber content in relation to WWTP discharge points on either river. Smaller mussels contained significantly more microfibers than larger mussels, despite differences in mussel size ranges between tributaries. These results reveal a potential pathway for microfibers to enter aquatic food webs and highlight important implications for the use of freshwater mussels as bioindicators of microfiber contamination.

现在，由于天然和合成纺织品的广泛使用，超细纤维在环境中无处不在。许多人通过废水处理厂（WWTP）的废水，地表水径流和大气沉积物进入水生系统，它们在那里持续存在，并可能被滤食生物吸收。除了造成物理损害（例如，消化道和呼吸道阻塞）外，微纤维通常还是化学污染物的载体，这些化学污染物也可能损害生物群。这项探索性研究旨在确定淡水贻贝（Margaritifera margaritiferaL.）圣约翰河两个农村支流之间的微纤维含量各不相同，微纤维含量是否与污水处理厂的排放点或潜在的分散微纤维来源有关，贻贝的大小是否与微纤维含量有关。在加拿大海洋沿海流域内两条河流的五个污水处理厂排放点的上游和下游以及其他11个点收集贻贝。两条河流之间的超细纤维含量差异显着。但是，在两条河流中，都没有观察到与WWTP排放点相关的超细纤维含量趋势。尽管支流之间的贻贝大小范围存在差异，但较小的贻贝比较大的贻贝含有更多的微纤维。