Lebepe Jeffrey, Khumalo Ntombifuthi, Mnguni Anele, Pillay Sashin, Mdluli Sphosakhe
School of Life Sciences, University of KwaZulu-Natal, Durban 4000, South Africa.
Department of Biology, School of Science and Technology, Sefako Makgatho Health Science University, Pretoria 0204, South Africa.
Biology (Basel). 2022 May 5;11(5):705. doi: 10.3390/biology11050705.
Urban rivers are regarded as unnatural because they drain catchments characterized by impervious surfaces. The present study explored macroinvertebrate communities in relation to water and habitat quality along the longitudinal gradient of an urban Palmiet River in Durban, South Africa. Sampling was conducted across six sites along the river. The water quality has shown a significant variation (ANOVA, p < 0.05) across six sites. Good-quality water was observed at Site 6, whereas Site 5 exhibiting hypertrophic condition. Sites 4 to 1 were all eutrophic; however, nutrient levels showed to decrease from Site 4 down to Site 2 and increased again at Site 1. A similar trend was observed for habitat quality, with Site 6 showing excellent and Site 5 exhibited poor habitat. Coinciding with water and habitat quality, macroinvertebrate diversity and abundance showed significant differences across six sites. Sensitive palaemonids, notonemourids, and amphipods were only observed in the headwaters and have contributed over 50% of the variation in abundance between Site 6 and other sites. The non-metric multidimensional scaling (NMDS) plot has also shown clear discrimination (MANOVA, p < 0.001) for the Average Score Per Taxon (ASPT) across the six sites. Macroinvertebrate communities have shown a clear association between water and habitat quality. These findings affirm the ecological importance of urban rivers as they provide refuge to aquatic biodiversity, with anthropogenic litter providing additional habitats for other taxa. Despite the current conditions supporting biodiversity and the functioning of the river, it is unclear if the system could endure further disturbance.
城市河流被视为非自然的，因为它们流经以不透水表面为特征的集水区。本研究探讨了南非德班一条城市帕尔米耶特河纵向梯度上大型无脊椎动物群落与水和栖息地质量的关系。沿着河流在六个地点进行了采样。六个地点的水质显示出显著差异（方差分析，p < 0.05）。在第6个地点观察到水质良好，而第5个地点呈现富营养化状态。第4至1个地点均为富营养化；然而，营养水平从第4个地点向下到第2个地点呈下降趋势，并在第1个地点再次上升。栖息地质量也观察到类似趋势，第6个地点显示出优良的栖息地，而第5个地点的栖息地较差。与水和栖息地质量一致，六个地点的大型无脊椎动物多样性和丰度存在显著差异。敏感的对虾科、异爪虾科和端足目动物仅在源头被观察到，并且它们在第6个地点和其他地点之间的丰度变化中贡献超过50%。非度量多维标度（NMDS）图也显示了六个地点每个分类单元平均得分（ASPT）的明显区分（多变量方差分析，p < 0.001）。大型无脊椎动物群落显示出水和栖息地质量之间存在明显关联。这些发现证实了城市河流的生态重要性，因为它们为水生生物多样性提供了庇护所，人为垃圾为其他分类群提供了额外的栖息地。尽管当前条件有利于生物多样性和河流功能，但尚不清楚该系统是否能够承受进一步的干扰。
