2011年1-7月对温瑞塘河后生浮游动物的群落结构及其栖息环境进行了调查,10个采样点共鉴定出后生浮游动物24种;其中,轮虫15种、枝角类6种、桡足类3种;优势种包括萼花臂尾轮虫(Brachionus calyciflorus)、壶状臂尾轮虫(B.urceus)、镰状臂尾轮虫(B.falcaty)、前节晶囊轮虫(Asplanchna priodonta)、长三肢轮虫(Filinialongiseta)、长足轮虫(Rataria neptunia)、指状许水蚤(Schmackeria inopinus)、广布中剑水蚤(Microcyclops leuckarti)和多刺裸腹溞(Moina macrocopa),优势种组成随季节变化略有不同;浮游动物的月均密度为13.39~310.8个/L,月均生物量为0.29~26.04 mg/L,两值均随水温的升高而增高;就空间分布状况看,浮游动物密度和生物量在各样点间存在明显差异。浮游动物与环境因子的典范对应分析(CCA)结果显示,温瑞塘河的水温是影响浮游动物密度变化最主要的因素(P≤0.05);而高锰酸钾指数(CODMn)、总氮(TN)和氨氮(NH4+)对浮游动物密度的分布也有重要影响,但总氮的变化趋势由NH4+的多少决定。建议在温瑞塘河水环境治理过程中,重点关注水体CODMn和NH4+的分布状况。
A seasonal investigation of meta-zooplankton was undertaken from January to July 2011 in Wenruitang River,Zhejiang.A total of 24 meta-zooplankton species were identified,including 15 Rotifera,6 Cladocera and 3 Copepoda.Dominant species included Brachionus calyciflorus,B.urceus,B.falcaty,Asplanchna priodonta,Filinia longiseta,Rataria neptunia,Schmackeria inopinus,Microcyclops leuckarti and Moina macrocopa,and the dominant species composition acrossed different sites in different seasons.Monthly mean densities of zooplankton ranged from 13.39 to 310.8 ind./L,and the biomass changed from 0.29 to 26.04 mg/L,both of which increased with water temperature.The density and biomass of zooplankton were significantly different in ten sites during investigation.According to the canonical correspondence analysis(CCA),the distribution of zooplankton was affected by ammonia nitrogen(NH+4),total nitrogen(TN),water temperature(Wt),chemical oxygen demand(CODMn),dissolved oxygen(DO),nitrite(NO-2),nitrate(NO-3) and chlorophyll(Chl-a).Among them,water temperature was the main factor and was significantly positively correlated with the density of zooplankton(P≤0.05).In addition,the density could also be affected to some extent by CODMn,TN and NH+4.Therefore,more attentions should be paid to the distribution of COD and NH+4 in Wentuitang River during improving the river water environment.