宜兴市莲花荡水系整治工程前后生态健康评价

以入太湖莲花荡水系为研究对象,结合2015年4个季度9个采样点的水质学、生物学共7个指标生态调查数据,采用多指标综合评价法,从生物完整性、化学完整性2个方面评价了莲花荡水系整治工程前后的生态健康状况。结果表明,2015年第1、2季度健康状况较差,健康的样点个数分别为3和1,在2015年6月开展清淤工程及集约化畜禽产业整改后,3、4季度健康状况明显改善,健康样点个数分别达到9和7。影响莲花荡水系化学完整性的主要水质指标是TN、TP,3、4季度TN仍超出地表水Ⅴ类标准,处于严重病态,TP为地表IV类标准,处于病态。影响莲花荡水系生物完整性的主要因子是底栖动物,仅监测到20种耐污能力较高的底栖动物物种,而未发现清洁物种。为了进一步改善莲花荡水系生态健康状况,建议开展沿岸农村生活污水的截污治理、农业面源的生态拦阻等污染源控工程,辅以生态岸带建设及湖滨带生态修复等工程。     

溶解有机质对生物富集因子计算的影响:以东江鱼体中多溴联苯醚的生物富集为例

准确获取化合物的生物富集因子(BAF)对于判定化合物是否属于潜在毒害性污染物、评价其生态环境风险都具有重要的意义。为探究水体中溶解有机质(DOM)对BAF值的影响,以东江三角洲流域为研究区域,以多溴联苯醚(PBDEs)为目标化合物,研究了PBDEs各单体在3种鱼体中的富集特征。结果表明,PBDEs在3种鱼体中的浓度范围为42~825 ng·g-1脂肪,log BAF值位于5.0~7.4之间。由于脱溴代谢的种间差异,3种鱼类表现出2种PBDE的组成模式。在缺乏脱溴代谢途径的鱼体内,log BAF与化合物辛醇/水分配系数(log KOW)之间存在统计意义上的抛物线关系。但当BAF进行DOM的校正之后,二者之间抛物线形式的相关性消失,而呈现出显著的正线性相关性。以往研究对BAF值在化合物的log KOW达到一定程度后(7~8附近)出现下降的解释是高KOW化合物较大的分子体积降低了其穿过生物膜的可能性,但我们的研究结果表明,这种下降很可能是由于忽视了水体中DOM影响的结果。     

A Chemical Characterization of A Lagoon Ecosystem: The Sacca Di Goro (Po River Delta, Italy)

This work reports on the results of a preliminary estimate of the presence and distribution of common and rare elements in a typical estuarine environment of the Po River Delta. Different environmental compartments (sediment, water, macroalgae and benthic animals) were considered, and analysis conducted on samples taken at two different sites characterized by low and high hydrodynamic regime. Resulting evidence of differences between the matrices, especially in relation to their different nature and sampling site are given.     

Elemental Analysis of Water and Sediments by External Beam Pixe Part 3: Axios (Vardar) River, Greece

The Axios (Vardar) River originates from the south west part of Yugoslavia, transverses Greece, and discharges into the Thermaikos bay in the north Aegean Sea.

The proton induced X-ray emission (PIXE) method with external beam was used for the elemental analysis of water and sediment samples, while measurements of water temperature, dissolved oxygen content, conductivity, pH, and the water flow were made in situ. Water samples were also analysed for total phosphates, nitrates, chlorophyll, and BOD. The data collected for a 16-month period indicate that the Axios River is polluted as far as the metal content is concerned; its primary productivity is low and it is slightly enriched during its course into the Greek territory.     

A 50-year sedimentary record of heavy metals and their chemical speciations in the Shuangtaizi River estuary (China): implications for pollution and biodegradation

Two parallel sediment cores collected from tidal flat located in the Shuangtaizi River estuary were analyzed for heavy metal concentrations and chemical speciations. Based on the ¹³⁷Cs activity profile, mean sedimentation rate at the sampling site during the past 50 years was estimated to be 1.3 cm·a^-1. Correlation analyses show that almost all the metals are associated with each other, suggesting that these metals might be derived from same sources and/or affected by same geochemical processes. Influence of total organic carbon (TOC) content on the concentrations of Cr, Ni, Cu and Cd is evident. Silt and clay contents, instead of sand content, play an important role in the distribution of these metals. The dominant binding phases for most of the metals (except for Cd) are the residual. The relative decrease of the residual fraction of Cd and Pb in the upper 66 cm of the core is striking. The distribution of chemical fraction confirms that the residual fractions of these metals have a natural origin, while only the non-residual fractions of Cd and Pb increased upward the core due to pollution in the past five decades. Pollution assessment on these heavy metals based on Index of Geoaccumulation (I_geo) also demonstrates that most of the metals are unpolluted. The weak pollution as observed in the sediments is perhaps related to a local plant, the Suaeda heteroptera Kitag, which may have played a significant role in the biodegradation of these metals and the metal distribution in the estuary.     

短期酸化对新安江流域屯溪段水体浮游植物群落结构及多样性的影响

为了探讨酸雨引起的水体酸化对新安江流域屯溪段浮游植物群落结构、丰度以及多样性的影响,对该流域3个采样站点以及流域附近一小型人工湖泊内浮游植物(同源性不同)进行调查并模拟酸胁迫(p H值4.50、5.65)处理。经酸化处理24 h后,各采样站点浮游植物与未经模拟酸雨处理的对照组相比种类及丰度呈降低趋势;较低p H值下(4.50)金藻门、黄藻门种类消失,优势种类硅藻门和绿藻门浮游植物受到的影响较大,种属数降低范围为0%~75%和27.3%~79.2%,蓝藻门受影响较小,裸藻门、甲藻门种属数未受影响;整体上各站点辛普森多样性指数、香农-维纳指数经酸化处理后均呈降低趋势。水体酸化对浮游植物种类与丰度的抑制效应在高NH3-N和总磷水平下较小。研究结果表明,不同门类浮游植物对酸胁迫的敏感性有较大差异,群落组成不同的水体,短期酸化处理都会显著改变浮游植物群落结构、降低浮游植物丰度以及多样性。作为长期受酸雨胁迫较为严重的地区,酸雨引起的水体酸化将可能成为影响新安江流域浮游植物群落结构的重要因子。     

Effects of Cd2+ exposure on key life history traits and activities of four metabolic enzymes in Helicoverpa armigera (Lepidopteran: Noctuidae)

Cadmium (Cd) is a toxic non-essential element accumulated easily in living organisms due to its non-biodegradable nature. A slight increase in Cd levels will threaten the health of terrestrial and aquatic organisms. Therefore, Cd contamination and its effects on the ecosystems and organisms have become a major topic of eco-toxicological research. The present study investigated the eco-toxicological effects of Cd-supplemented diet on some life history traits and specific enzyme activities of carboxylesterase (CarE), glutathione S-transferase (GST), acetylcholinesterase (AChE) and cytochrome P450 monooxygenases (P450s) in the cotton bollworm, Helicoverpa armigera. The results showed that Cd significantly decreased larval survival, pupation and emergence, and reduced body mass of the sixth instar larvae, pupae, adult moths and female fecundity. Cd-supplemented diet also delayed the development of larvae and pupae and shortened the life span of the cotton bollworm moth. In addition, dietary Cd inhibited the activities of GST, CarE and P450, but increased AChE activity of the sixth instar larvae. We concluded that life history traits and metabolic enzymes are sensitive to Cd stress in the cotton bollworm. These parameters are potential biomarkers for monitoring environmental stress in Lepidopteran insect pests.     

Seasonal variation and partition of trace metals (Fe, Zn, Cu, Mn, Cr, Cd and Pb) in surface sediments: relationship with physico-chemical variables of water from the Calabar River, South Eastern Nigeria

The seasonal variation and partition of trace metals (Fe, Cu, Zn, Mn, Cd, Cr and Pb) in the surface sediments of the Calabar River are reported. Chemical partition of the metals in the sediments reveals that 2–30% of the total metal load was contributed by the non-detrital (acid-soluble) fraction, while fine-grained host minerals/compounds are the main carriers of the detrital (acid-insoluble) fraction (70–98%). Using multivariate statistical analysis, the seasonal fluctuations in the distribution of some of the metals show significant influence by physio-chemical changes (dissolved oxygen, pH, salinity and conductivity) in the water column. Fe–Mn oxide grain coatings and sulphide materials have been identified as scavengers of some of the non-detrital and detrital trace metals in the sediments. On the basis of index of geoaccumulation (I-geo) and comparison with previous studies, the Calabar River surface sediments have been classified as unpolluted.     

湖南省境内长江中上游防护林体系建设第一期工程的进展

长江中上游防护林建设第一期工程1990年在湖南省境内启动实施以来,先后在全省33个县(市、区)开展了工作,共完成投资22 284.8万元,重点造林工程项目主要采取人工植苗造林、低效林改造、封山育林和幼林抚育等 4种方式,在整个长江防护林建设工程过程中始终坚持良种壮苗技术的推广和造林树种选择及其造林技术的研究。长江防护林建设重点工程占43.84%,一般营造林占56.16%;该建设工程获得的生态效益总计达到51 980.87万元,直接经济效益共计706 283.63万元,为社会提供了43.6万个劳动力一年就业岗位,文末还指出了该建设工程中存在的5个方面问题及3项对策。     

贫营养型水库中罗非鱼对浮游植物的影响:围隔实验

于2009年9～11月在贫营养型的大型深水水库(流溪河水库)中进行了围隔(体积约为85 m3)实验,分析了罗非鱼对浮游植物的影响.根据水库中现有鱼类的生物量,设置加鱼处理组(2 g/m3)和无鱼对照组两组.每组有3个重复,实验开始后每周采样一次,测定水质与采集浮游生物定性和定量样品.实验结果表明,加鱼处理组和对照组的总氮、可溶性无机氮没有明显差别,实验后期的总磷与正磷有一定差别,处理组略高于对照组.加鱼处理组浮游植物丰度及生物量、叶绿素a的含量显著高于对照组(P<0.05),且透明度低于对照组,个体小于30μm的浮游植物种类的丰度与生物量较明显增加,浮游动物丰度显著低于对照组(P<0.05),但是生物量差异不显著(P>0.05).总的来说,在贫营养条件下,低生物量的罗非鱼对水库浮游植物群落结构仍有着明显的影响,罗非鱼排泄产生的上行效应大于摄食产生的下行效应.     

A patch use model to separate effects of foraging costs on giving-up densities: an experiment with white-tailed deer (<Emphasis Type="Italic">Odocoileus virginianus</Emphasis>)

The giving-up density of food (GUD), the amount of food remaining in a patch when a forager ceases foraging there, can be used to compare the costs of foraging in different food patches. But, to draw inferences from GUDs, specific effects of foraging costs (predation risk, metabolic and missed opportunities costs) on GUDs have to be identified. As high predation risk, high metabolic costs and abundant food all should produce high GUDs, this does not allow us to infer directly the quality of a habitat. In order to separate the effect of each foraging cost, we developed an optimal foraging model based on food supplementation. We illustrate the use of our model in a study where we assessed the impact of a power line right-of-way in a white-tailed deer (Odocoileus virginianus) winter yard by determining whether the negative effects of cover loss outweigh the positive effects of browse regeneration.