云贵高原富营养化湖泊杞麓湖浮游生物群落的季节性演替及其驱动因子分析

杞麓湖是云贵高原典型的重富营养化湖泊,水生态系统已严重退化.为揭示杞麓湖浮游生物群落季节性演替规律,阐明浮游生物群落季节性演替的驱动因子,于2017-2018年对杞麓湖浮游生物及水质理化参数进行季节采样调查和浮游生物群落结构特征分析,并运用CCA（典范对应分析）方法分析浮游植物群落组成与环境因子的关系.结果表明:①杞麓湖夏季营养状态最高,达重度富营养水平,春秋冬三季均为中度富营养.水体SD（透明度）春季最高,夏季最低;ρ（Chla）、ρ（COD_Mn）均为夏季最高,冬季最低;ρ（TN）冬季最高,秋季最低;ρ（TP）春夏最高,冬季最低.②杞麓湖浮游植物共6门163种（其中包括8个变种）.浮游植物密度春季最低（0.66×108 L-1）而秋季最高（16.08×108 L-1）,主要为蓝藻门、绿藻门和硅藻门.其中,春季优势种为微细转板藻（Mougeotia parvula）;夏季优势种为孟氏浮丝藻（Planktothrix mougeotii）;秋冬季的优势种均为阿氏浮丝藻（Planktothrix agardhii）.③杞麓湖浮游动物32种,浮游动物密度冬季最低（13.2 ind./L）而夏季最高（3 696.0 ind./L）.其中,春季优势种为曲腿龟甲轮虫（Keratella valga）,夏季优势种为前节晶囊轮虫（Asplanchna priodonta）,秋季优势种为螺形龟甲轮虫（Keratella cochlearis）,而冬季优势种为桡足类幼体.研究显示,杞麓湖浮游动植物群落季节性演替明显,ρ（DTP）（DTP为溶解态磷）、ρ（TP）、ρ（NH₃-N）、ρ（COD_Mn）和WT（水温）是影响杞麓湖浮游植物群落季节性演替的主要驱动因子.      

三峡库区典型支流水库浮游动植物群落结构特征及其与环境因子的关系

为了探讨三峡库区典型支流水库（长寿湖）浮游动植物结构与环境因子间的关系,于不同季节对其水环境因子和浮游动植物进行调查,利用Pearson相关性分析法对调查结果进行分析.对浮游动植物的鉴定结果表明：浮游植物共有8门107种,主要由相对丰度达61%的蓝藻门组成,优势种群包括纤细席藻、点状平裂藻和类颤藻鱼腥藻这3种浮游植物.共鉴定出浮游动物4门82种,其中轮虫相对丰度达88%,其优势种群包括螺形龟甲轮虫、前节晶囊轮虫和盖氏晶囊轮虫等6种浮游动物.浮游动植物丰度、生物量和生物多样性指数的空间差异均不显著,除浮游动物生物多样性指数季节性差异不显著外,其余指标均有显著的季节性差异.夏季浮游植物的丰度最高,春季次之,冬季最低,而浮游动物春季丰度最高,春季浮游动植物的生物量均显著高于冬季.夏季浮游植物的种类数,Shannon-Wiener指数（H''）、Pielous均匀度指数（J）和Margalef丰富度指数（D）显著低于冬季和春季.水质评价结果表明,冬、春季节长寿湖水质处于清洁-寡污状态,夏季处于中度污染状态,长寿湖整体处于富营养化状态.影响长寿湖浮游动植物群落结构的环境因子包括：Chla、DOC、TP、NO₂^--N、NO₃^--N、NH₄⁺-N、DO、Eh和T.冬春夏3个季节影响浮游动植物群落结构的环境因子存在差异.     

Full-scale study of removal effect on Cyclops of zooplankton with chlorine dioxide

Cyclops of zooplankton propagated excessively in eutrophic water body and could not be effectively inactivated by the conventional disinfections process like chlorination due to its stronger resistance to oxidation. In this paper, a full-scale study of chlorine dioxide preoxidation cooperating with routine clarification process for Cyclops removal was conducted in a waterworks. The experimental results were compared with that of the existing prechlorination process in several aspects: including the Cyclops removal efficiencies of water samples taken from the outlets of sedimentation tank and sand filter and the security of drinking water and so on. The results showed that chlorine dioxide might be more effective to inactivate Cyclops than chlorine and Cyclops could be thoroughly removed from water by pre-dosing chlorine dioxide process. The GC-MS examination and Ames test further showed that the sort and amount of organic substance in the treated water by chlorine dioxide preoxidation were evidently less than that of prechlorination and the mutagenicity of drinking water treated by pre-dosing chlorine dioxide was substantially reduced compared with prechlorination.     

富营养湖泊中轮虫群落结构季节变化的环境驱动力研究(英)

通过对桥墩湖一周年的逐月采样,比较了影响轮虫群落结构季节变化的3种环境驱动力的相对重要性。桥墩湖是一个富营养湖泊,具有较高的营养盐和Chl a含量以及低的透明度。研究发现：水温和营养水平是影响轮虫数量和群落结构季节变化最重要的理化因子。由于大型枝角类数量的稀少,其对轮虫数量并没有显著的负面影响。短尾秀体溞是影响轮虫群落结构季节变化的最重要的枝角类;然而大多数优势轮虫与短尾秀体溞密度峰值的共同出现可能反映了它们对高营养水平和高水温的共同喜好。在浮游植物中,绿藻是决定轮虫密度的最重要的浮游植物门类;而其中的隐藻则是影响轮虫群落结构变化的最重要属。3组环境因子(理化因子、浮游植物、浮游甲壳动物)对轮虫群落结构的季节变化具有相似的解释大小。这些结果表明：在该富营养湖泊中,轮虫群落结构的季节变化可能主要受理化因子和食物资源的影响;浮游甲壳动物对轮虫群落结构的塑造作用有限     

突发环境污染事件对湖泊浮游动物的影响

中国北方某地空难对某湖泊浮游动物的种类、群落结构、优势种和个体密度及其空间分布产生了重要影响.基于浮游动物的水质生物学评价显示:①该湖泊有浮游动物24种,其中原生动物9种,优势种为累枝虫;轮虫7种,优势种为萼花臂尾轮虫;枝角类4种,优势种为直额裸腹;桡足类4种,优势种为直刺北镖水蚤;浮游动物优势种多为α-中污带或β-中污带的指示种类和富营养化指示种类. ②浮游动物个体密度(4 770 L-1)较小且分布不均匀,空难事故发生地及其附近区域的种类数和个体密度均为最低值,桡足类在其中4个样点没有出现. ③浮游动物的Shannon-Wiener多样性指数略高于1,结合浮游动物个体密度、群落结构、优势门类和种类,可以认为该湖泊水体污染和富营养化程度比较严重,这一结果与该湖泊水质理化评价结果(1.030 5)基本一致.      

三都湾生态监控区(近海部分)浮游动物的分布特征

根据2004年三都湾生态监控区(近海部分)浮游动物的监测资料,分析了该海域浮游动物的种类组成和数量分布特征.经分析,鉴定出浮游动物139种及浮游幼体和幼虫54种(类),分5个生态类群,以暖水近岸类群为主.本海域主要优势种有:拟细浅室水母、中华哲水蚤、强额拟哲水蚤、刺尾纺锤水蚤、肥胖箭虫、短尾类溞状幼虫.该海域浮游动物种类数5月从北向南有下降的趋势;8月由北向南呈上升的趋势,各断面种类数有由近岸向外上升的趋势.5月份浮游动物平均生物量明显高于8月份.     

毒死蜱对六种淡水节肢动物的毒性与风险评价

采用静态法测定了毒死蜱对六种水生节肢动物的48 h毒性.试验结果表明,按实测浓度计,毒死蜱对大型溞Daphnia magna、老年低额溞Simocephalus vetulus、多刺裸腹潘Moina macrocopa、锯缘真蚤Eucyclops serrulatus、介形虫Pseudocandona sp.、花翅摇蚊Chironomus kiiensis幼虫的48 h-LC50(单位:μg· L-1)分别为0.523、0.0528、0.178、7.32、2.75、90.3.这表明毒死蜱对于上述6种水生节肢动物均属于剧毒.将稻田施药下的环境浓度预测值(EECs)与基于实测浓度的48 h-LC50相比对,得到毒死蜱相对于6种水生节肢动物的急性风险商值(RQ)分别为10.29、52.95、27.20、0.73、1.96、0.06.这说明除了摇蚊幼虫,按推荐剂量使用的毒死蜱对于其他5种水生节肢动物有较高程度的急性风险.     

Zooplankton responses to hydrological and trophic variability in a Mediterranean coastal ecosystem (Lesina Lagoon,South Adriatic Sea)

Spatial and temporal variability in zooplankton was studied at eight stations located in the Lesina Lagoon (South Adriatic Sea) Salinity, temperature, dissolved oxygen and chlorophyll a (in the lagoon) at these stations were also assessed. The zooplankton community was characterised by clear seasonal oscillations and mostly represented by copepods and their larvae. The dominant copepod species were Calanipeda aquaedulcis and Acartia tonsa, which exhibited spatial–temporal segregation in the lagoon. C. aquaedulcis copepodites seemed to be better adapted to oligotrophic and oligohaline conditions compared with the A. tonsa population. The invasive species A. tonsa has completely replaced the formerly abundant Acartia margalefi. A positive correlation was found between abundances, total species numbers and trophic state. An increasing abundance trend was shown from the lagoon towards the sea. The highest diversity indices were recorded at the two channel inlets, during high tide due to the absence of a clear dominance of one or more coastal species and the co-occurrence of species of lagoon and marine origin.     

Exploration of relationships between phytoplankton biomass and related environmental variables using multivariate statistic analysis in a eutrophic shallow lake： A S-year study

Understanding the process of the changing phytoplankton patterns can be particularly useful in water quality improvement and management decisions. However, it is generally not easy to illustrate the interactions between phytoplankton biomass and related environmental variables given their high spatial and temporal heterogeneity. To elucidate relationships between them, in a eutrophic shallow lake, Taihu Lake, relative long-term data set of biotic and abiotic parameters of water quality in the lake were conducted using multivariate statistical analysis within seasonal periodicity. The results indicate that water temperature and total phosphorus （TP） played governing roles in phytoplankton dynamics in most seasons （i.e. temperature in winter, spring and summer; TP in spring, summer and autumn）; COD （chemical oxygen demand） and BOD （biological oxygen demand） presented significant positive relationships with phytoplankton biomass in spring, summer and autumn. However, a complex interplay was found between phytoplankton biomass and nitrogen considering significant positive relationships occurring between them in spring and autumn, and conversely negative ones in summer. As the predatory factor, zooplankton presented significant grazing-pressure on phytoplankton biomass during summer in view of negative relationship between them in the season. Significant feedback effects of phytoplankton development were identified in summer and autumn in view that significant relationships were obser,qed between phytoplankton biomass and pH, Trans （transparency of water） and DO. The results indicate that interactions between phyto：plankton biomass and related environmental variables are highly sensitive to seasonal periodicity, which improves understanding of different roles of biotic and abiotic variables upon phytoplankton variability, and hence, advances management methods for eutrophic lakes.     

水动力对浮游生物影响的围隔研究

利用3个围隔装置,于2007年8月～2008年7月间研究了0.002、0.10、0.15和0.30 m.s-1共4种表面流速对围隔内浮游植物和浮游动物生长的影响.结果表明,0.15、0.30 m.s-1这2种表面流速下围隔内壁附着水绵生物量分别是对应静止条件下的2.3倍和31.3倍,0.10、0.15和0.30 m.s-1这3种表面流速下围隔内Chl-a浓度分别为对应静止围隔中的45%、54%和26%,浮游动物生物量分别为对应静止围隔中的38%、27%和6%.这些现象的作用机制可能在于水动力产生的剪切力促进水绵的营养生殖、紊动强制裹挟浮游植物破坏其光生境、水绵繁殖抑制浮游植物生长和水动力扰动降低浮游甲壳动物捕食成功率.