Eriksen Tor E, Brittain John E, Sandin Leonard, Friberg Nikolai
Norwegian Institute for Water Research (NIVA), Økernveien 94, 0579 Oslo, Norway; Natural History Museum, University of Oslo, P O Box 1172 Blindern, 0318 Oslo, Norway.
Natural History Museum, University of Oslo, P O Box 1172 Blindern, 0318 Oslo, Norway; Norwegian Water Resources & Energy Directorate (NVE), P O Box 5091 Majorstuen, 0301 Oslo, Norway.
Sci Total Environ. 2025 Jan 1;958:178064. doi: 10.1016/j.scitotenv.2024.178064. Epub 2024 Dec 17.
Human activities present significant threats to tropical freshwater ecosystems, notably in many global biodiversity hotspots, threats that are further increased by inadequate taxonomic knowledge and the lack of appropriate biomonitoring tools. This study integrates globally validated biomonitoring approaches with DNA-based identification methods to create a macroinvertebrate-based tool for diagnosing ecosystem health and assessing the biodiversity of tropical river ecosystems in Myanmar (Indo-Burma bioregion). To evaluate river site degradation, comprehensive data on water and habitat quality, as well as land use information, were collected. Riverine macroinvertebrates were sampled by kick sampling, and subsequent DNA barcoding analysis was used to establish molecular taxonomic units (MTUs) for key bioindicator groups, including Ephemeroptera, Plecoptera, Trichoptera, Coleoptera, and Odonata (EPTCO) as species-level identification nomenclature was lacking. Tolerance scores for the local fauna were derived along an environmental degradation gradient to enable comparisons with widely adopted global assessment tools relying on macroinvertebrate metrics. In both study areas, the upper parts of the river networks were generally undisturbed by human activities while stressors associated with urban and agricultural land use were evident in the lower parts of the catchments. The highest precision for assessment of river health was found when establishing tolerance scores adjusted to local species composition in each study area separately. Although a family-level-based multimetric approach was significantly related to the main environmental degradation gradient, assessments utilizing cryptic species-level data (MTUs) emerged as the being most precise indicator in both areas. Our study highlights the synergistic benefits of merging traditional biomonitoring with DNA-based methods for species identification for biomonitoring in tropical river ecosystems. To halt biodiversity decline and curb the extent of the escalating nature crisis, such integrated approaches will be highly valuable in understudied and biodiversity-rich aquatic ecosystems.
人类活动对热带淡水生态系统构成了重大威胁，特别是在许多全球生物多样性热点地区，而分类学知识不足和缺乏适当的生物监测工具进一步加剧了这些威胁。本研究将全球经过验证的生物监测方法与基于DNA的识别方法相结合，创建了一种基于大型无脊椎动物的工具，用于诊断缅甸（印缅生物区）热带河流生态系统的健康状况并评估其生物多样性。为了评估河流站点的退化情况，收集了有关水质和栖息地质量的综合数据以及土地利用信息。通过踢网采样法对河流大型无脊椎动物进行采样，随后利用DNA条形码分析为关键生物指示类群建立分子分类单元（MTU），由于缺乏物种水平的识别命名法，这些类群包括蜉蝣目、襀翅目、毛翅目、鞘翅目和蜻蜓目（EPTCO）。根据环境退化梯度得出当地动物群的耐受分数，以便与广泛采用的依赖大型无脊椎动物指标的全球评估工具进行比较。在两个研究区域中，河网的上游部分通常未受人类活动干扰，而与城市和农业土地利用相关的压力源在集水区下游很明显。当分别针对每个研究区域根据当地物种组成调整耐受分数时，发现评估河流健康状况的精度最高。尽管基于科级的多指标方法与主要环境退化梯度显著相关，但利用隐存物种水平数据（MTU）进行的评估在两个区域中均是最精确的指标。我们的研究强调了将传统生物监测与基于DNA的物种识别方法相结合对热带河流生态系统生物监测的协同效益。为了阻止生物多样性下降并遏制不断升级的自然危机的程度，这种综合方法在研究不足且生物多样性丰富的水生生态系统中将非常有价值。
