为了掌握秦皇岛洋河水库底栖动物分布状况，并据此进行水质评价，设置了6个采样点，分别于2006年5月、8月、9月和11月四个时间段共采集了24个样品。分析结果表明：在洋河水库底泥中共发现底栖动物11种，其中10种能够指示污染程度，耐污种类占绝对优势；所有样点的底栖动物个体密度介于680～5 920个/m2，全库平均为1 924个/m2，水库整体处于中～富营养水平；底栖动物生物量介于1.68～38.76g/m2，全库平均为8.53 g/m2；底栖动物生物多样性指数介于0.64～1.89，水库整体水质介于中度污染～重度污染。鉴于底栖动物在水质评价方面不可替代的作用，建议该水库每隔5～10年做一次系统的底栖动物调查。

In order to investigate the distribution of benthic fauna in the Yanghe Reservoir and its effects on water quality, 24 samples were collected at six sites in May, August, September, and November 2006. The results showed that (1) eleven species of benthic fauna are observed, among which ten species are capable of pollution indication, and the pollution-resistance species are dominant; (2) the density of benthic fauna at the six sampling?sites are from 680 to 5 920 ind/m2, whereas the average density in the whole reservoir is 1 924 ind/m2, indicating that the reservoir is moderate tropic to eutrophic; (3) the average biomass of benthic?fauna at the six sampling?site is between 1.68 and 38.76 g/m2 whereas the average biomass density in the whole reservoir is 8.53 g/m2; and (4) the biodiversity index of benthic fauna in the reservoir is between 0.64 and 1.89, and the pollution level of the reservoir is between moderate pollution and heavy pollution. Due to its importance in assessment of water quality, the benthic fauna in the reservoir need to be investigated every 5 to 10 years.