Surveys of anthropogenic pressures and their effect on river fish communities have rarely been conducted in the eastern Mediterranean countries, in contrast to the rest of Europe. An electrofishing dataset of 1586 samples (818 sites) was analyzed to investigate human-induced pressures on river fish assemblages in Greece. Pressure patterns and pressure-impact analysis towards the national fish bioassessment index (HeFI) and its four constituent metrics are depicted. At each sampling site 11 anthropogenic pressure variables were assessed, and several integrated/grouped pressure indices were computed, including hydrology, morphology, connectivity, and water quality. Almost 60% of samples were classified as impacted. The most common pressure groups affecting Greek rivers were hydrology recorded at 714 (45%) samples, morphology at 692 (44%) and artificial barriers at 382 (24%) samples. A similar pattern persists among the six investigated freshwater ecoregions in Greece. The most impacted ecoregions were Thrace (76% impacted samples), Western Aegean (67% impacted samples) and Macedonia-Thessaly (67% impacted samples). Lowlands and large rivers displayed higher levels of degradation, but water pollution was not recognized as a key stressor in most running waters. Pressure-impact analysis demonstrates that all HeFI component metrics (insectivorous, omnivorous, benthivores, potamodromous species) respond as expected to almost all integrated pressure indices considered, as regards: a) the direction of response, and b) the response to pressure intensity gradients. However, the longitudinal connectivity stressor clearly fails to respond towards metrics. The findings confirm the usefulness of model-based indices, using fish assemblage functional metrics as bioassessment tools. Specific recommendations for refining the tools are provided.

与欧洲其他地区相比，在地中海东部国家很少进行人为压力及其对河流鱼类群落影响的调查。分析了 1586 个样本（818 个地点）的电捕鱼数据集，以调查人为对希腊河鱼群的压力。描述了对国家鱼类生物评估指数 (HeFI) 及其四个组成指标的压力模式和压力影响分析。在每个采样点评估了 11 个人为压力变量，并计算了几个综合/分组压力指数，包括水文、形态、连通性和水质。近 60% 的样本被归类为受影响的样本。影响希腊河流的最常见压力组是在 714 个（45%）样本中记录的水文，692 (44%) 样本的形态和 382 (24%) 样本的人工屏障。在希腊被调查的六个淡水生态区中也存在类似的模式。受影响最大的生态区是色雷斯（76% 受影响的样本）、西爱琴海（67% 受影响的样本）和马其顿-色萨利（67% 受影响的样本）。低地和大河流的退化程度更高，但水污染并未被认为是大多数流水的主要压力源。压力影响分析表明，所有 HeFI 成分指标（食虫性、杂食性、底栖动物、水生物种）对所考虑的几乎所有综合压力指数都有预期的响应，涉及：a) 响应方向，和 b) 对压力强度梯度的响应. 然而，纵向连接压力源显然无法对指标做出反应。研究结果证实了基于模型的指数的有用性，使用鱼类组合功能指标作为生物评估工具。提供了改进工具的具体建议。