【作者】 成芳；

【导师】 凌去非；

【作者基本信息】 苏州大学 ， 水生生物学， 2010， 硕士

【摘要】 太湖是我国的第三大淡水湖泊,位于长江三角洲南缘,是太湖流域内的主要饮用水水源,并兼有蓄洪、灌溉、航运、旅游、养殖等功能。近50年来,由于人类不当的生产活动和环境污染等原因,导致太湖湖泊富营养化、水质碱化、生态破坏以及水质恶化等环境问题不断出现。其中富营养化已成为太湖最重要的水环境问题之一。2007年11月到2008年8月,我们按季度对太湖的水化学指标及水生生物群落结构进行了调查分析。通过水质污染指数评价法和综合富营养化指数法对太湖的水化学分析表明,太湖的主要污染物为氮(N)、磷(P)和有机耗氧量(CODMn)。总磷(TP)所占的污染负荷指数最大(34.34%~54.34%),平均污染指数为48.36%。叶绿素a(Chl-a)与TN、TP和CODMn之间呈显著正相关,Pearson相关系数分别为0.715(p<0.01)、0.666(p<0.01)和0.740(p<0.01)。采用综合营养状态指数法评价太湖的水质状态,发现太湖四个季节的TLI(∑)值均在60~70之间,平均值为65.54,各季节的水质状态差异较小。太湖水质整体上已处于中度富营养状态,部分区域已呈严重富营养化。太湖的浮游植物主要由8大门类组成,分别为蓝藻门、绿藻门、硅藻门、隐藻门、甲藻门、黄藻门、裸藻门和金藻门。蓝藻、绿藻和硅藻占浮游藻类个体总量的90%左右,其中尤以蓝藻门占绝对优势。蓝藻门全年均能发现,且全湖性分布。优势种为:铜绿微囊藻(Microcystis aeruginosa )和水华微囊藻(M. flosaquae)。太湖浮游植物密度平均值为1.87×107 ind?L-1,生物量平均值为5.36 mg?L-1。浮游植物多样性指数的变化在0.16~2.43之间,平均为1.08。均匀度指数的变化在0.08~0.82之间,平均为0.41。均匀度指数与多样性指数结果都显示太湖水体的状况处于中度污染状态。太湖浮游动物中,原生动物常见种为球形砂壳虫(Difflugia gloculosa)、长圆砂壳虫(Difflugia oblonga)、钟虫(Vorticella sp.),大弹跳虫(Halceria grandinella)、筒壳虫(Tintinnidium fluviatile stein)、累枝虫(Epistylis sp.)、坛状曲颈虫(Cyphoderia ampulla Ehrenberg)。优势种为表壳虫、球形砂壳虫、筒壳虫、累枝虫。轮虫中的萼花臂尾轮虫(Brachionus calycif lorus ),龟甲轮虫属(Keratella sp.)的三种轮虫全年都有出现。常见种还有角突臂尾轮虫(Brachionus angularis),螺旋龟甲轮虫(Keratella cochlearis);曲腿龟甲轮虫(Keratella ualga ),长三肢轮虫(Filinia longiseta),针簇多肢轮虫(Polyarthra trigla)。枝角类的优势种为象鼻溞(Bosmina sp.)、网纹溞(Ceriodaphnia sp.)、秀体溞(Diaphanosoma sp.)。桡足类主要是剑水蚤(Cyclops sp.),哲水蚤(Sinocalanus sp.)为次优势种。浮游动物数量变化在410.93ind?L-1到8672.05ind?L-1之间,均值为3277.19ind?L-1。生物量的变化在1.04mg?L-1到11.73mg?L-1之间,均值为5.35mg?L-1。太湖浮游动物多样性指数的变化在0.03~1.88之间,平均为0.90,浮游动物多样性指数随着温度升高而升高,且夏秋的多样性指数大于冬春。太湖底栖生物种类23种,其中腹足类15种,双壳类1种,节肢动物4种,环节动物3种。主要的底栖生物种类为双壳类的河蚬(Corbicula ftuminea),腹足纲的中华圆田螺(Cipangopaludina cathayensis),以及环节动物门颤蚓(Tubifiex sinicus),出现率分别为73.2%,21.4%和44.6%。湖心区以河蚬为主要优势种,东太湖以长角涵螺、光滑狭口螺为优势种,梅梁湾和五里湖的优势种为钩虾及耐污染的颤蚓。与历史数据相比,底栖生物的种类数明显减少,而耐污性种类的数目相对增加。更多还原

【Abstract】 Taihu Lake is the third largest fresh lake in China, located in the southern margin of the Yangtze River Delta, Taihu Lake basin is the main drinking water source, and both flood storage, irrigation, shipping, tourism, culture and so on. In the past 50 years, due to improper human activities and environmental pollution and other factors of production, leading to eutrophication, water alkalinity, ecological destruction and the deterioration of water quality and other environmental issues.Eutrophication of the lake is one of the most important water environmental problems. So the index of Taihu Lake water chemistry and aquatic community structure were investigated according to a quarterly from November 2007 to August 2008.We evaluate the actual condition of water quality and the main pollutions of Taihu Lake by ways of water pollution index and comprehensive analysis of eutrophication. Evaluation of water pollution index analysis revealed that the main pollutants in Taihu Lake were nitrogen (N), phosphorus (P) and organic oxygen consumption (CODMn). Total phosphorus (TP) shared the largest pollution load index (34.34% ~ 54.34%), the average pollution index for 48.36%. TN, TP and CODMn had significant positive correlations with Chlorophyll-a (Chl-a), Pearson correlation coefficients were 0.715 (p<0.01), 0.666 (p<0.01) and 0.740 (p<0.01) respectively. According to comprehensive analysis of nutritional status indicators, it also showed that TLI (Σ) values of Taihu Lake were between 60 and 70 in four seasons, with a mean value of 65.54. The seasonal changes of water quality were small. In a word,Taihu Lake was in a moderately eutrophication, and some of the region had shown a serious eutrophication.The main phytoplankton constitute 8 phylum, there were Cyanophyta, Cryptophyta, Pyrrophyta, Chrysophyta, Xanthophyta, Bacillariophyta, Euglenophyta and Chlorophyta. Cyanophyta, Chlorophyta and Bacillariophyta accounted for phytoplankton was about 90% of the total individuals, especially the predominant spiece of Cyanophyta. Cyanophyta can find throughout the year and of the whole lake. The dominant species were Microcystis aeruginosa and M. flosaquae. The average density of phytoplankton was 1.87×107 ind?L-1, the average biomass was 5.36 mg?L-1. The phytoplankton diversity index changes from 0.16 to 2.43 and the average of diversity index was 1.08. Evenness index changes from 0.08 to 0.82 with an average of 0.41.The results of diversity index and evenness index showed that the situation of Taihu Lake was moderately polluted.The common protozoa species were Difflugia gloculosa, Difflugia oblonga, Vorticella sp., Halceria grandinella, Tintinnidium fluviatile stein, Epistylis sp. and Cyphoderia ampulla Ehrenberg. Dominant species were Tintinnidium fluviatile stein, Vorticella sp., Difflugia gloculosa and Epistylis sp.. Brachionus calycif lorus and three kinds of rotifer in Keratella sp. occur throughout the year. The commom rotifer contain Brachionus angularis, Keratella quada, Keratella ualga, Filinia longiseta and Polyarthra trigla.The dominant species of Cladocera were Bosmina sp., Ceriodaphnia sp. and Diaphanosoma sp..The dominant specie of Copepoda was Cyclops sp. and the sub-dominant specie was Sinocalanus sp..The number of zooplankton Change between 410.93 ind?L-1 and 8672.05 ind?L-1, the mean 3277.19ind?L-1. Biomass changes between 1.04 mg?L-1and 11.73 mg?L-1, the mean is 5.35 mg?L-1. The zooplankton diversity index changes from 0.03 to 1.88 and the average was 0.90, zooplankton diversity increased as the temperature rises, and the diversity index higher in summer and autumn than winter and spring.The investigation of Taihu Lake benthic community showed the main benthic organisms were Corbicula ftuminea, Cipangopaludina cathayensis and Tubifiex sinicus. The frequencies of occurrence about dominant species were 73.2%, 21.4% and 44.6%. A total of 23 species of the benthos were collected: 15 species of Gastropod,1 species of Mussels,4 species of Arthmpoda,3 species of Annelida. The main dominant species is Corbicula ftuminea in middle area of Taihu Lake, Alocinma longicornis and Stenothyra glabra in East Taihu Lake, Gammarus and Tubifiex in Meiliang Bay and Lake Wuli. Compare to the historical data, the species of benthic organism reduced significantly. And the number of stain resistance species increased.更多还原