Abstract We assessed water quality using physical, chemical, and biological characteristics in 37 streams between Puerto Maldonado and Cusco in Peru. Study sites ranged from ∼200 to 4000 m in elevation, with streams selected as pairs (control/natural vs. human impacted) along this gradient. In general, temperature decreased (R2 = 0.82) and other parameters increased [dissolved oxygen (R2 = 0.19), conductivity (R2 = 0.17), pH (R2 = 0.37)] with elevation. Macroinvertebrates were hand collected by professional entomologists and using leaf packs implemented by conservation workers. The professionals identified 213 unique taxa from the hand collections, with 80 species collected only one time. Data from control streams showed that as elevation increased, total richness (p = 0.008) and EPT richness (p = 0.050) decreased whereas Diptera richness increased (p = 0.002). NMS ordination indicated significant differences in macroinvertebrate assemblages when control streams from low and high elevations were contrasted. Hand collections also revealed significant differences between control and impact streams for total richness, EPT richness and % Diptera, but not for % EPT, % EPT richness, or % Diptera richness. The majority of the deployed leaf packs were successfully retrieved and contained many macroinvertebrates (Avg. = 141 individuals per pack). There were 98 unique taxa (family level or higher) identified from the leaf packs by the trained conservation workers. Fourteen of 15 macroinvertebrate community metrics (at the family level) were able to detect significant differences between control and impact sites. All of the family level metrics responded similarly across the elevation gradient except total richness, EPT richness, EPT count, and % Hydropsychids. Both the Costa Rica and the Virginia Save Our Stream Indexes were able to differentiate control from impacted streams using leaf pack data. Although the diversity of macroinvertebrates was higher for hand collections relative to leaf packs (due to greater habitats sampled and higher taxonomic resolution), leaf pack samples were better able to distinguish control from impacted streams. Specifically, leaf packs were able to discern impacts in streams at low elevation better than those at high elevation. Generally, macroinvertebrates indicated impact from urbanization to be worse than impacts from other human activities (i.e., gold mining and agriculture). Overall, hand collections will serve as an important reference of species diversity going forward while leaf packs processed by trained conservation workers are a viable method to monitor stream water quality in Peru and perhaps elsewhere.

中文翻译：

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使用手工和叶包收集的大型无脊椎动物评估秘鲁跨洋公路沿线亚马逊河流的水质

摘要 我们使用物理、化学和生物特征评估了秘鲁马尔多纳多港和库斯科之间 37 条河流的水质。研究地点的海拔范围从 200 米到 4000 米不等，沿此梯度成对选择溪流（控制/自然与人类影响）。一般来说，温度降低（R2 = 0.82）和其他参数增加[溶解氧（R2 = 0.19），电导率（R2 = 0.17），pH值（R2 = 0.37）]随着升高。大型无脊椎动物由专业昆虫学家手工收集，并使用保护工作者实施的叶包。专业人士从手部收藏品中识别出 213 个独特的分类群，其中 80 个物种只收集了一次。来自控制流的数据显示，随着海拔的增加，总丰富度 (p = 0.008) 和 EPT 丰富度 (p = 0. 050) 减少而双翅目丰富度增加 (p = 0.002)。当来自低海拔和高海拔的控制流进行对比时，NMS 排序表明大型无脊椎动物组合存在显着差异。手工收集还揭示了控制流和影响流之间在总丰富度、EPT 丰富度和双翅目百分比方面的显着差异，但在 % EPT、% EPT 丰富度或双翅目丰富度百分比方面没有显着差异。大多数部署的叶包被成功回收并包含许多大型无脊椎动物（平均每包 141 只）。受过训练的保护工作者从叶子包中识别出 98 个独特的分类群（家庭级别或更高）。15 个大型无脊椎动物群落指标中的 14 个（在家庭级别）能够检测到控制点和影响点之间的显着差异。除了总丰富度、EPT 丰富度、EPT 计数和 Hydropsychids 百分比外，所有家庭级别的指标在海拔梯度上的响应都相似。哥斯达黎加和弗吉尼亚拯救我们的河流指数都能够使用叶包数据区分控制与受影响的河流。尽管与叶包相比，手工采集的大型无脊椎动物的多样性更高（由于采样的栖息地更大，分类分辨率更高），但叶包样本能够更好地区分控制和受影响的溪流。具体来说，与高海拔地区相比，树叶群能够更好地识别低海拔地区溪流中的影响。一般来说，大型无脊椎动物表明城市化的影响比其他人类活动（即金矿和农业）的影响更严重。全面的，