人为活动对冈曲河大型底栖动物空间分布的影响

为监测人为活动对高海拔山区河流的影响,以香格里拉冈曲河为例,应用多维统计分析与排序分析,探讨大型底栖动物群落对人为活动的响应. 研究表明,冈曲河受到低浓度重金属污染,农业活动和水体富营养化程度相对较轻,总体水质状况符合国家地表水环境质量标准(GB3838—2002)Ⅰ,Ⅱ类水质标准. 聚类分析显示,大型底栖动物群落可分为4组:组Ⅰ(北支翁水河)与组Ⅱ(南支格咱河)采样点受人为活动的影响最轻;组Ⅲ采样点主要受开矿和农业活动影响;组Ⅳ采样点受重金属污染相对较重. 4组采样点在无度量多维标定法(NMS)排序轴上的分布差异明显,组Ⅰ与组Ⅱ采样点体现出空间分布差异,而人为活动主要影响组Ⅲ与组Ⅳ采样点. 随河级增加,底栖动物的群落结构除受到水深、河宽、水温、浊度和海拔高度等环境因子的影响外,组Ⅲ与组Ⅳ采样点影响底栖动物群落退化的主要因素为Cu,Pb和NO-₃-N. 石蛭科和毛缘蛾蚋为组Ⅰ采样点的指示种;叉襀和倍叉襀等敏感类群为组Ⅱ采样点的主要指示种;组Ⅲ的指示种为中耐污种短石蛾和蜉蝣,以及强耐污种寡毛类;涡虫为组Ⅳ采样点的指示种,表明涡虫具有较高的重金属污染耐受性.      

石油污染滩涂生物体内TPH分布及健康风险评估

通过研究溢油事故污染区域中典型生物体内TPH（Total Petroleum Hydrocarbons）分布特征,对其进行暴露人体健康风险评估,从而为污染区域的生态系统修复与恢复工作提供指导依据。在研究区域受溢油污染并采取应急处置10个月后,采集了位于4个污染滩涂集中填放区和1个不受污染的对照区内的生物体和沉积物样品,采用紫外分光光度法和荧光分光光度法测得 TPH 含量。结果表明,污染区域中无齿螳臂相手蟹 Chiromantes dehaani）肌肉组织中的 TPH 含量分布范围为2.94~39.63 mg·kg-1,内脏中的TPH含量分布范围为8.62~155.41 mg·kg-1,内脏组织中的TPH含量高于肌肉组织,两者呈显著的相关性（Pearson相关系数r=0.9456）。受潮汐水动力等环境因素的影响,整个研究区域生物体内TPH的累积呈现不连续非均质特征。生物体肌肉和内脏组织中的TPH含量与沉积物中TPH含量具有明显的线性关系（y=283.3 x+100,r2=0.9901;y=60.701 x+100,r2=9038）,溢油事故造成的沉积物污染是影响生物体内TPH累积的一个重要因素。同时,采用US EPA人体暴露风险评价方法进行人体健康风险评估,结果显示,污染区域生物体内TPH经口摄入的暴露风险指数ERI均值均大于1,分别为1.13、1.05、2.58、2.73,暴露风险处于不可接受水平。根据人体健康风险的可接受水平计算得出可接受的无齿螳臂相手蟹体内TPH安全值为34.4 mg·kg-1,进一步计算得出污染区域沉积物中TPH的修复目标值为2513 mg·kg-1。     

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。     

BENTHIC INVERTEBRATES IN A NORTH-FLOWING STREAM AND A SOUTH-FLOWING STREAM,BROOKS RANGE,ALASKA1

ABSTRACT: Benthic invertebrate faunas were compared to two fifth-order streams, the Atigun River flowing northward and the Dietrich River flowing southward. Sixty-eight taxa were collected, forty-nine from each stream. Aquatic insects comprised 88% of the taxa and 97% of the individuals from the Dietrich River and 73% of the taxa and 97% of the individuals from the Atigun River. Diptera, especially Chironomidae, were most abundant. Plecoptera, Ephemeroptera, Oligochaeta, Acarina, and Collembola were significant. In both streams the headwaters were dominated by the subfamily Diamesinae which was replaced by Orthocladiinae downstream. Diversity seemed to increase with stream order. Cluster analysis showed a high degree of resemblance between the benthic faunas of the rivers. Faunal resemblance decreased with increasing distance between stations, both within and between the streams. Although some taxa may occur in only one stream, the evidence for faunal resemblance is stronger than for faunal differences. Other studies have shown that differences in total radiation associated with valley aspect affect local climate, hydrology, and distribution of terrestrial plants and animals. However, the benthic faunas of Atigun and Dietrich Rivers were remarkably similar. Factors which operate independently of aspect, possibly freezing solid in winter, may control the occurrence of species in these streams.     

A BASKET SAMPLING TECHNIQUE FOR QUANTIFYING RIVERINE MACROBENTHOS1

ABSTRACT: A colonization basket sampling technique for quantifying macroinvertebrates in rubble bottom rivers is described. Basket samplers were compared to collections made using the Surber square foot sampler. Procedure for processing samples is described. Macrobenthos were more accurately quantified by basket samplers because both surface and subsurface habitats were sampled, no organisms were lost when samplers were removed from the river, substrata and associated fauna were retained for analysis, and the samplers were used efficiently in both pool and riffle areas. At the end of the colonization period the basket samplers contained one-half cubic foot of river bottom and macroinvertebrates spatially arranged within.     

Toxicity Evaluation with the Microtox Test to Assess the Impact of In Situ Oiled Shoreline Treatment Options: Natural Attenuation and Sediment Relocation

Changes in the toxicity levels of beach sediment, nearshore water, and bottom sediment samples were monitored with the Microtox^® Test to evaluate the two in situ oil spill treatment options of natural attenuation (natural recovery--no treatment) and sediment relocation (surf washing). During a series of field trials, IF-30 fuel oil was intentionally sprayed onto the surface of three mixed sediment (pebble and sand) beaches on the island of Spitsbergen, Svalbard, Norway (78°56^′ N, 16°45^′ E). At a low wave-energy site (Site 1 with a 3-km wind fetch), where oil was stranded within the zone of normal wave action, residual oil concentrations and beach sediment toxicity levels were significantly reduced by both options in less than five days. At Site 3, a higher wave-energy site with a 40-km wind fetch, oil was intentionally stranded on the beach face in the upper intertidal/supratidal zones, above the level of normal wave activity. At this site under these experimental conditions, sediment relocation was effective in accelerating the removal of the oil from the sediments and reducing the Microtox^® Test toxicity response to background levels. In the untreated (natural attenuation) plot at this site, the fraction of residual oil remaining within the beach sediments after one year (70%) continued to generate a toxic response. Chemical and toxicological analyses of nearshore sediment and sediment-trap samples at both sites confirmed that oil and suspended mineral fines were effectively dispersed into the surrounding environment by the in situ treatments. In terms of secondary potential detrimental effects from the release of stranded oil from the beaches, the toxicity level (Microtox^® Test) of adjacent nearshore sediment samples did not exceed the Canadian regulatory limit for dredged spoils destined for ocean disposal.     

环境治理与保护中工程菌研究进展

介绍了目前环境治理与保护中工程菌，特别是基因工程菌的研制方法、应用情况以及各国生物安全管理办法。     

Assessment of the Ecological Integrity of Traunsee (Austria) Via Analysis of Sediments and Benthic Microbial Communities

Since nearly one hundred years Traunsee experiences the import of tons of liquid and solid waste originating from salt and soda production. Today, the lake exhibits chloride concentrations of up to 170 mg L^-1 and 19% of the lake floor are directly or indirectly influenced by industrial deposits (ID). Based on the comparison of several microbial parameters in unaffected, directly affected and intermediate lake bottom sediments, the ecological integrity of the lake was evaluated. The highly alkaline ID, which were exclusively colonized by microorganisms, harbored a bacterial community reduced by a factor of 10 in abundance and biomass compared to undisturbed sediment areas within the lake. The bacterial community of ID was furthermore characterized by a reduced content of actively respiring cells (INT-formazan reduction), a lower frequency of dividing cells (FDC) and a significantly reduced cell and biomass production. A 80 to 90% reduction in carbon recycling is estimated for the area exclusively covered by ID. Protists, although occasionally absent from the industrial sediments, were in general found to be less sensitive to the contaminant stress. Differences in alkalinity and dissolved organic carbon (DOC) concentrations of sediment porewaters as well as the total organic content and C/N ratios of sediments partly explain the microbial pattern observed at the various sampling sites. Possible consequences of the continuous industrial tailings for the whole lake ecosystem and the validation of the ecological integrity are discussed.     

A biological assessment of best management practice effectiveness during intensive silviculture and forest chemical application

A multi-year study was conducted to evaluate the effectiveness of Florida's Best Management Practices (BMPs) for protecting aquatic ecosystems during intensive forestry operations and forest chemical applications. Five silviculture sites adjacent to stream systems were selected for study from major eco-regions of the state. Replicate stream bioassessments, using a multimetric approach (the Stream Condition Index), were conducted as part of a `before-after, control-impact' (BACI) study design. Bioassessment stations were established above and below the treatment area to determine pre-treatment reference and test conditions. Silviculture treatments of clearcut harvesting, intensive mechanical site preparation and machine planting were then completed, during which all applicable BMPs were adhered to. In addition, two sites received an herbicide application and one site was fertilized. Following the treatments, the sites were re-sampled at the same points both one year, and two years after the first bioassessment. No significant differences in the SCI were observed between the reference and test portions of the streams that could be attributed to the silviculture operations using BMPs. Hence, the study showed that BMPs provided protection to adjacent stream ecosystems, even during intensive silviculture and forest chemical applications.     

STREAM DEPTH SIGNIFICANCE DURING IN‐SITU SEDIMENT OXYGEN DEMAND MEASUREMENTS IN SHALLOW STREAMS1

ABSTRACT: Ninety‐one sediment oxygen demand (SOD) samples from six designated sites along the stretch of Lower Rapid Creek, South Dakota, were conducted using an in‐situ SOD chamber. Inside the chamber, readings of dissolved oxygen (DO), water temperature, pH, and specific conductance were recorded every minute for more than one hour using the Datasonde 3 Hydrolab. Initial readings of such parameters were recorded for the overlaying water before the deployment of the SOD chamber. Characteristics of the stream conditions, air temperature, barometric pressure, average flow velocity of the stream, depth of the stream, and the flow velocity by the chamber were recorded. Single and multiple linear regression analyses on all parameters indicated that the velocity of the stream is the least critical parameter for SOD in shallow streams.