Across the Afrotropical ecosystems human activities are increasingly modifying natural flow regimes, nutrient and organic matter loading and processing in streams and rivers with implications on ecosystem structure and functioning. The Mara River Basin has undergone extensive land-use change, but influences of these changes on water quality and aquatic communities are not well understood. This study investigated changes in water quality and macroinvertebrate assemblages across a disturbance gradient arising from rural human activities in nineteen sites; grouped into three condition categories (reference undisturbed (n = 7), moderately disturbed (n = 6) and disturbed (n = 6)). Temperature, dissolved oxygen, total dissolved solids, pH and electrical conductivity were measured in situ at each sampling site, and samples collected for analysis of nutrients and total suspended solids. Sampled macroinvertebrates were identified mainly to family level for analysis of structural and functional composition. There were significant spatial variations in water quality variables across the disturbance gradient (p <0.05). Highest mean temperature and suspended solids were recorded at the disturbed sites and lowest at undisturbed sites. Ephemeroptera, Plecoptera and Trichoptera (EPT) taxa dominated (70% in abundance) undisturbed sites while Diptera dominated (48% in abundance) at disturbed sites. Additionally, higher diversity and richness indices were recorded at undisturbed sites. Collectors were the dominant taxa at all sites with the abundance of shredders being highest at undisturbed sites. This study adds further evidence showing that land-use change from forestry to agriculture has a strong influence on the structural and functional composition of macroinvertebrates in Afrotropical streams.

在整个非洲热带生态系统中，人类活动越来越多地改变溪流和河流中的自然流动状态、营养物质和有机物质的装载和加工，对生态系统的结构和功能产生影响。马拉河流域经历了广泛的土地利用变化，但这些变化对水质和水生群落的影响尚不清楚。本研究调查了 19 个地点农村人类活动引起的扰动梯度中水质和大型无脊椎动物组合的变化；分为三个条件类别（参考未受干扰 (n = 7)、中度受干扰 (n = 6) 和受干扰 (n = 6)）。原位测量温度、溶解氧、总溶解固体、pH 值和电导率在每个采样点，收集的样品用于分析养分和总悬浮固体。采样的大型无脊椎动物主要被鉴定为家庭级别，用于分析结构和功能组成。在整个扰动梯度（p<0.05）。最高平均温度和悬浮固体记录在受干扰的地点，最低的则是在未受干扰的地点。蜉蝣目、全翅目和毛翅目 (EPT) 类群在未受干扰的地点占主导地位（70% 的丰度），而双翅目在受干扰的地点占主导地位（48% 的丰度）。此外，在未受干扰的地点记录了更高的多样性和丰富度指数。收集者是所有地点的主要分类群，在未受干扰的地点，碎纸机的数量最多。这项研究提供了进一步的证据，表明从林业到农业的土地利用变化对亚热带河流中大型无脊椎动物的结构和功能组成有很大的影响。