PDF(Pubmed)
Abstract：
Freshwater aquatic ecosystems are threatened globally. Biological monitoring is required to deliver rapid and replicable assessment of changes in habitat quality. The Ephemeroptera, Plectoptera, Trichoptera (EPT) index is a globally recognised rapid bioassessment that measures taxa richness of three insect orders whose larvae are considered sensitive to freshwater habitat degradation. South-western Australia contains threatened freshwater ecosystems but has depauperate EPT fauna and high endemism, potentially reducing the capacity of the EPT index to track degradation. This study investigated if EPT species richness, composition or individual species tracked physical or chemical river degradation in three catchments in south-western Australia. We sampled EPT fauna and measured water chemistry, erosion, sedimentation, riparian vegetation cover and instream habitat at 98 sites in the winters of 2007 and 2023. We found 35 EPT taxa across the study area with a median number of species per site of two. EPT species richness had weak positive associations with a composite water quality index and dissolved oxygen and weak negative associations with electrical conductivity and total nitrogen. No association was found between physical and fringing zone degradation measures and EPT species richness. EPT community structure generally did not distinguish between sites with high or low degradation levels. The presence of the mayfly Nyungara bunni tracked salinity, dissolved oxygen and nitrogen levels, but its usefulness as a bioindicator could be limited by its restricted range. This study suggests that the EPT index would need modification or combination with other indices to be a useful rapid bioassessment in south-western Australia.
摘要：
淡水水生生态系统在全球范围内受到威胁。需要进行生物监测，以便对栖息地质量的变化进行快速和可复制的评估。星翅目,Plectoptera,毛翅目（EPT）指数是全球公认的快速生物评估，可测量三种昆虫的分类群丰富度，这些昆虫的幼虫被认为对淡水栖息地退化敏感。澳大利亚西南部包含受威胁的淡水生态系统，但EPT动物区系贫瘠，地方性高，潜在地降低了EPT指数跟踪退化的能力。这项研究调查了EPT物种丰富度，在澳大利亚西南部的三个流域中，成分或单个物种追踪了河流的物理或化学退化。我们采样了EPT动物群并测量了水化学，侵蚀,沉降,2007年和2023年冬季，98个地点的河岸植被覆盖和河流栖息地。我们在整个研究区域发现了35个EPT分类单元，每个地点的物种数量中位数为2。EPT物种丰富度与复合水质指数和溶解氧的正相关较弱，与电导率和总氮的负相关较弱。在物理和边缘区退化措施与EPT物种丰富度之间没有发现关联。EPT群落结构通常无法区分降解水平高或低的位点。MayflyNyungaraBunni的存在追踪了盐度，溶解氧和氮水平，但其作为生物指示剂的有用性可能受到其有限范围的限制。这项研究表明，EPT指数需要修改或与其他指数结合才能成为澳大利亚西南部有用的快速生物评估。
