清河水库的浮游生物

根据1970,1973,1974,1977,1978和1979年17次采样测定的结果,清河水库浮游植物量平均约6毫克/升,其中硅藻占58.6%,甲藻占25.9%。浮游动物量平均1.95毫克/升,其中桡足类约占44%,枝角类约40%,轮虫和原生动物约16%。浮游植物量上游和中游接近而远高于下游,一般秋季高于其他季节,但1978年夏季特别高。浮游动物量也是中游和上游通常高于下游,夏季最高,秋季次之。在生物量中占优势的主要种类有:颗粒直链藻、扭曲小环藻、隐藻、角甲藻、剑水蚤及其无节幼体、象鼻溞、长刺溞、多肢轮虫等。文中讨论了浮游生物分布和变化的某些规律和水库的营养类型及鲢鳙鱼的生产潜力。  

STUDIES ON THE PLANKTON IN QINGHE RESERVOIR

This paper presents the results of investigation on the plankton of Qinghe reservoir during the six years: 1970, 1973—74 and 1977—79, The reservoir is located in Liaoning Province, Northeastern China, with an submerged area of 46 km and a mean depth of about 10 m (maximum depth 30—33 m).The standing crop of phytoplankton in Qinghe reservoir during the surveying period varied from 1.05 to 24.41 mg/l, among which Bacilladophyta was the most predominant group, being 58.6% of the total biomass. Next came Pyrophyta (25.9%), Cyanophyta (8.0%), Chlorophyta (3.5%), Chrysophyta (2.8%) and Euglenophyta (only 1.0%).The average biomass of zooplankton was 1.95 (0.34—10.51) rag/l, in which the copepoda presented 44.1%, the Cladocera—40% and the Rotifera and Protozoa—only 15.9%.About 40 dominant or most common forms occur in the reservoir. The most important species of them are: Melosira granulata, Cyclotella comta, Cryptomonas sp, Ceratium hirundinella, Bosmina coregoni, Daphnia longispina, Cyclopida and Polyarthra trigla.In general, the biomass of phytoplankton and zooplankton is higher at the upper and middle reaches than that at the lower reach. The phytoplankton is maximum in autumn and the zooplankton is maximum in summer, but in 1978 the phytoplankton maximum shifted to Summer owing to an extraordinary low water level.In this paper the distribution and fluctuations of the plankton and the potential fish productivity of Qinghe reservoir are also discussed.