松花江下游底栖动物群落结构与水质生物学评价

1999—2005年对松花江下游江南屯断面及支流梧桐河断面进行了11次底栖动物生态调查.调查期间共发现底栖动物39种，其中水生昆虫21种，软体动物12种，环节动物4种，甲壳动物2种.江南屯与梧桐河底栖动物的种类组成呈现显著差异，在发现的39种底栖动物中，仅有14种于两断面都有分布.分布于江南屯断面的主要底栖动物及其出现率为:纹石蚕100%,箭蜓80%,黑龙江短沟蜷80%,钩虾80%,二尾蜉60%,细蜉60%,灯蛾蜉60%,东北田螺60%.分布于梧桐河断面的主要底栖动物及其出现率为:黑龙江短沟蜷100%,东北田螺100%,扁蛭100%,珍珠蚌60%.从栖息密度来看，梧桐河断面中软体动物密度最大, 优势种为东北田螺，江南屯断面则以水生昆虫占优势.此外，两断面的底栖动物数量在不同年份也存在显著变化.水质生物学评价结果表明，梧桐河断面多年处于中污染状态，江南屯断面的污染状况在总体上较梧桐河断面轻，这主要是由于梧桐河断面高负荷的耗氧有机物引起水体中溶解氧含量匮乏，从而导致底栖动物的生存条件严重恶化. 

The Community Structure of Zoobenthos and Bioassessment of Water Quality in the Lower Reaches of the Songhua River

From 1999 to 2005,11 times of zoobenthos ecological investigations were carried out in the Jiangnantun section of the downstream Songhua River and the section of in its branch river,Wutonghe River.In total,39 species of zoobenthos were found,of which 21 species were aquatic insects,12 species molluses,4 species annelids and 2 species crustaceans.Significant differences in the species composition of zoobenthos were found between the two sampling sites of Jiangnantun and Wutonghe,and there were only 14 species distributing at both of the sampling sites.The zoobenthos and occurrence rates at Jiangnantun section are: Hydropsyche 100%,Gomphidae 80%,Semisulcospira amurensis 80%,Gammaridea 80%,Cloeon 60%,Caenidae 60%,Viviparus chui 60%.The zoobenthos and occurrence rates at Wutonghe section are: Semisulcospira amurensis 100%,Viviparus chui 100%,Glossiphonia sp.100%,Margarites 60%.In Wutonghe section,the density of molluses was highest,with the dominant species being Viviparus chui,while the dominant species in Jiangnantun section were aquatic insects.At the both sampling sites,the density of zoobenthos also varied significantly between the different years.The result of bioassessment of water quality revealed that the water in Wutonghe section was polluted to moderate extent during these years,while the water in Jiangnantun section was polluted to slight or moderate extent.The worse water quality in Wutonghe section was caused most possibly by the lower dissolved oxygen.