In this study, we analyzed the impacts of different environmental conditions on aquatic worm communities along the Danube River, based on two longitudinal surveys, the Joint Danube Surveys 2 and 3 (JDS; 2007 and 2013). We identified the most important environmental factors (among analyzed groups) that shape worm communities: hydromorphlogical alterations, flow velocity and substrate (HYMO group), dissolved oxygen, nitrates and nitrites (physico-chemical parameters), zinc and nickel (metals), monobutyltin cation, benzo(b) fluoranthene and benzo(k)fluoranthene, polychlorinated biphenyls PCB 77 and PCB 118 (selected chemical determinants—organotin compounds, Polycyclic aromatic hydrocarbons—PAHs and PCBs). A homogenization of species composition of Oligochaeta assemblages along the Danube was confirmed. As one of main factors related to biotic homogenization, hydromorphological alterations represented by similar changes in flow velocity and substrates along Danube’s course could be singled out. Our results indicate that Oligochaeta could be used for the identification of the level of hydromorphological degradation in large rivers (homogenization), rather than for stressors classified as nutrient and organic pollutants. Our results provide additional evidence in risk assessment of the environment, contributing in water management and monitoring of the ecological status as proposed by the Water Framework Directive.

中文翻译：

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多瑙河沿岸的水生蠕虫组合：同质化警告

在这项研究中，我们基于两项纵向调查，即联合多瑙河调查 2 和 3（JDS；2007 和 2013），分析了不同环境条件对多瑙河沿岸水生蠕虫群落的影响。我们确定了塑造蠕虫群落的最重要的环境因素（在分析的组中）：水形改变、流速和底物（HYMO 组）、溶解氧、硝酸盐和亚硝酸盐（物理化学参数）、锌和镍（金属）、单丁基锡阳离子、苯并 (b) 荧蒽和苯并 (k) 荧蒽、多氯联苯 PCB 77 和 PCB 118（选定的化学决定因素——有机锡化合物、多环芳烃——多环芳烃和多氯联苯）。证实了多瑙河沿岸寡毛纲组合物种组成的同质化。作为与生物均质化相关的主要因素之一，可以挑出多瑙河沿线流速和基质的类似变化所代表的水形态学改变。我们的结果表明，寡毛纲可用于识别大河流中的水文形态退化水平（均质化），而不是用于分类为营养物和有机污染物的压力源。我们的结果为环境风险评估提供了额外的证据，有助于水管理和水框架指令提出的生态状况监测。我们的结果表明，寡毛纲可用于识别大河流中的水文形态退化水平（均质化），而不是用于分类为营养物和有机污染物的压力源。我们的结果为环境风险评估提供了额外的证据，有助于水管理和水框架指令提出的生态状况监测。我们的结果表明，寡毛纲可用于识别大河流中的水文形态退化水平（均质化），而不是用于分类为营养物和有机污染物的压力源。我们的结果为环境风险评估提供了额外的证据，有助于水管理和水框架指令提出的生态状况监测。