Protective properties of filamentous blue–green alga Spirulina against the oxidative stress induced by cadmium in freshwater mussel Unio ravoisieri

ABSTRACT

Cadmium (Cd) is a toxic-heavy metal that induces a wide range of behavioural, biochemical and physiological effects in aquatic organisms. Oxidative damage has been proposed as a possible mechanism involved in cadmium toxicity. The current study was carried out to evaluate the antioxidant activity of Spirulina as feed additive (1?mg/L) against the toxicity of cadmium (Cd) 0.5?mg/L in freshwater mussel Unio ravoisieri. At the end of the exposed period of 4 days, digestive gland antioxidant status Superoxide dismutase, Catalase, Glutathione-S-transferase and damage markers such as Malondialdehyde and Protein carbonyl were determined. Associations between biomarkers were assessed by a multivariate analysis technique, principal component analysis (PCA). The results of this study revealed that digestive gland antioxidant status showed a significant decrease when mussels were exposed to Cd. Superoxide dismutase, Catalase and Glutathione-S-transferase activities in the Cd?+?SP group were significantly higher than the Cd group (p P?相似文献   

太子河着生藻类群落结构空间分布特征

以辽宁省太子河流域为研究范例,调查了全流域内69个采样点的着生藻类群落和水环境理化特征,并且以着生藻类的群落结构为基础,对太子河流域的水生态系统类型区进行了划分. 结果表明,太子河流域着生藻类群落结构具有明显的空间异质性. CCA(典范对应分析)结果显示,驱动全流域着生藻类群落结构形成的水环境因子为电导率、ρ(TDS)(TDS为总溶解固体)和ρ(TN). 基于着生藻类的群落结构特征,将太子河流域划分为3个着生藻类类型区:第1分区为太子河上游的森林多水区,第2分区为中游低山丘陵森林区,第3分区为下游平原农业区. CCA结果还显示,显著影响第1分区、第2分区及第3分区的着生藻类群落结构的环境因子分别为ρ(NO₃--N)、ρ(TN)及ρ(总溶解固体)和硬度.      

物种敏感度分布的非参数核密度估计模型

针对目前物种敏感度分布参数方法建模所存在的缺点,首次提出基于非参数核密度估计方法的物种敏感度分布模型,并提出相应的最优窗宽和检验方法。选用无机汞作为案例研究对象,利用非参数核密度估计方法和3种传统参数模型分别推导了保护我国水生生物的无机汞的急性水质基准值。结果表明,非参数核密度估计方法在推导无机汞水质基准中的稳健性和精确度都大大优于传统参数模型,能够更好地构建物种敏感度分布曲线。该方法的提出丰富了水质基准的理论方法学,为更好地保护水生生物提供了有力的支撑。     

A roadmap for the conservation of freshwater mussels in Europe

Europe has a long history of human pressure on freshwater ecosystems. As pressure continues to grow and new threats emerge, there is an urgent need for conservation of freshwater biodiversity and its ecosystem services. However, whilst some taxonomic groups, mainly vertebrates, have received a disproportionate amount of attention and funds, other groups remain largely off the public and scientific radar. Freshwater mussels (Bivalvia, Unionida) are an alarming example of this conservation bias and here we point out six conceptual areas that need immediate and long-term attention: knowledge, threats, socioeconomics, conservation, governance and education. The proposed roadmap aims to advance research, policy and education by identifying the most pressing priorities for the short- and long-term conservation of freshwater mussels across Europe.     

Chemometric approach to evaluate element distribution in muscle,liver and fish bone of roach (Rutilus rutilus), silver bream (Blicca bjoerkna) and crucian carp (Carassius carassius) from Swarzędzkie Lake (Poland) using ICP-MS and FIAS-CVAAS techniques

The content of elements in fish tissues and organs from Swarz?dzkie Lake was investigated in order to evaluate the possible risk associated with their consumption by animals as well as humans. Samples of muscle, liver and fish bone of three fish species; roach (Rutilus rutilus), silver bream (Blicca bjoerkna) and crucian carp (Carassius carassius) were collected from seine catches undertaken as part of the biomanipulation of Swarz?dzkie Lake. Element concentration (Al, As, Cd, Co, Cr, Cu, Hg, Ni, Pb, Zn) was determined by inductively coupled plasma mass spectrometry (ICP-MS), with the exception of Hg where the flow injection analysis system cold vapour atomic absorption spectrometry (FIAS-CVAAS) was applied. The study indicated a large variation in the occurrence of the investigated elements in different parts of the fish body. The highest content of Al and Zn was stated in all fish organs for each fish species. The majority of the applied statistical and chemometric methods (e.g., PCA, CA) refer to roach since we had a large number of data for this species. The obtained results were assessed in terms of their accuracy and precision using certified reference material of Fish Muscle ERM BB422.     

Linking Soil Erosion to Instream Dissolved Phosphorus Cycling and Periphyton Growth

Phosphorus (P) is a limiting nutrient in freshwater systems and when present in runoff from agricultural lands or urban centers may contribute to excessive periphyton growth. In this study, we examined the link between soil erosion and delivery of eroded soil to streams during flow events, and the impact of that freshly deposited soil on dissolved reactive P (DRP) concentrations and periphyton growth under baseflow conditions when the risk of stream eutrophication is greatest. A microcosm experiment was designed to simulate the release of P from soil which had been amended with different amounts of P fertilizer to overlying water during baseflow conditions. Unglazed tiles, inoculated for five days in a second order stream, were incubated for seven days in microcosms containing soil with eight levels of soil Mehlich‐3 plant available phosphorus (M3P) ranging from 20 to 679 mg/kg M3P. Microcosm DRP was monitored. Following incubation tiles were scraped and the periphyton analyzed for chlorophyll a. Microcosm DRP concentrations increased with increasing soil M3P and equilibrium phosphorus concentration (EPC₀). Relationships between M3P, EPC₀, and DRP were nonlinear and increases in soil M3P and/or DRP had a greater impact on biomass accumulation when these parameters were above threshold values of 30 mg/kg M3P and 0.125 mg/L DRP. Significantly, this ecological threshold corresponds to the agronomic thresholds above which increased soil M3P does not increase plant response.     

淡水鱼脑AChE的动力学特性及抗抑制性

用PEG2000双水相萃取、DEAE-Sephadex A-50和SephadexG-200方法分离提纯麦穗鱼(Pseudorasbora parva)、金鱼(Carassius auratus)和虹鳟鱼(Salmo gairdneri)脑乙酰胆碱酯酶(AChE),比较这3种淡水鱼脑AChE纯酶液与粗酶液的动力学特性、抗抑制性及其种类之间的差异.结果表明,这3种鱼脑AChE的性质在种类间的差异要远远小于其在粗酶状态时酶活性的差异,由此得出AChE性质在种类间的差异并非影响这3种淡水鱼脑AChE活性差异的主要因素;由AChE抗抑制试验结果可知,这3种鱼脑AChE粗酶液对经溴水氧化后的马拉硫磷和三唑硫磷的敏感性及种间的差异都远大于纯酶液.     

基于淡水资源账户和污染账户的生态足迹改进模型

论文通过增加淡水资源账户和污染账户,对通用的生态足迹模型进行改进,弥补了生态足迹模型中对淡水资源和对生态系统消纳污染物描述的不足,增强了生态足迹模型计测的准确性;同时以实际土地平均生产力法对东江流域涉及地市赣州、 梅州、 河源、 韶关、 惠州、 广州、 东莞和深圳等城市2008年的产量因子进行调整,计算了东江流域涉及8市2008年的生态足迹。结果表明:①2008年东江流域涉及各市的生态足迹和生态承载力差异较大,意味着各市之间的社会经济状况和资源禀赋大不相同。总的人均生态足迹的空间分布为除惠州和深圳外,有由上游至中下游增加的趋势;除淡水外的可利用人均生态承载力的空间分布,则呈现由上游至中下游减少的趋势。②生态足迹的空间变化随人均GDP和/或城镇人口比例的增加呈先增加后减少的趋势,这一结论或许能给流域内外的其他城市就如何减少乃至消除区域生态赤字提供一点启示,指出其经济社会发展的道路和下一步应该努力的方向。③各市除淡水外的总生态足迹均大于其生态承载力,因而整个流域不同程度地均存在生态赤字,即按照当前状况,这些地区都需要继续从区域以外的地方输入自然产品和资源及能源才能维持正常的发展。     

北京市场常见淡水食用鱼体内农药残留水平调查及健康风险评价

利用超声波提取-气质联用法调查了北京市不同水产品市场4种常见淡水食用鱼体内25种农药的残留水平,并利用商值法评价了农药的潜在健康风险.在采集的48个样品中,除七氯、o,p’-DDT、敌敌畏、对硫磷、毒死蜱、仲丁威和久效磷以外,其余18种农药均有不同程度检出.其中,检出率最高的为乙草胺(97.9%)和β-六六六(93.8%);检出农药含量最高的为百菌清(1 779.4μg·kg-1),其次为溴氰菊酯(620.3μg·kg-1).鱼体中有2～10种农药共存,其总浓度为2.7～1 932μg·kg-1.潜在健康风险评价结果表明,按照北京市民的平均水产品消费量,北京水产品市场上的4种主要食用鱼中的农药风险商值为0.043 43,处于较低水平.     

模拟氮沉降对闽江口淡水感潮沼泽湿地CO2、CH4排放通量的短期影响

为了评价氮沉降对我国亚热带河口区淡水感潮沼泽湿地CO_2、CH_4排放通量的影响,在福建闽江口道庆洲淡水感潮短叶茳芏沼泽湿地,设置对照CK[0 g·(m~2·a)~(-1)]及3个梯度的氮沉降处理:N1[24 g·(m~2·a)~(-1)]、N2[48 g·(m~2·a)~(-1)]和N3[96 g·(m~2·a)~(-1)],采用静态箱-气相色谱法测定短叶茳芏湿地CO_2、CH_4排放通量,并同步观测相关环境因子.结果表明,(1)与对照相比,N1处理CO_2排放通量增加20.30%,N2处理CO_2排放通量减少10.05%,N3处理CO_2排放通量增加4.06%,除了12月的N2、N3处理CO_2排放通量与对照间有显著差异外(P0.05),其它时间各处理间CO_2排放通量差异性不显著(P0.05).(2)与对照相比,N1处理CH_4排放通量提高64.51%,N2处理CH_4排放通量提高30.23%,N3处理CH_4排放通量提高80.57%,但是各处理间CH_4排放通量的差异性未达到显著水平(P0.05).(3)CO_2、CH_4排放通量与土壤温度具有显著的正线性相关关系(P0.05),与土壤EC、土壤p H的相关性不显著(P0.05).