Subsampling program for the estimation of fish impingement

Federal regulations require operators of nuclear and coal-fired power-generating stations to estimate the number of fish impinged on intake screens. During winter months, impingement may range into the hundreds of thousands for certain species, making it impossible to count all intake screens completely. We present graphs for determinig the appropriateoptimal subsample that must be obtained to estimate the total number impinged. Since the number of fish impinged tends to change drastically within a short time period, the subsample size is determined based on the most recent data. This allows for the changing nature of the species-age composition of the impinged fish. These graphs can also be used for subsampling fish catches in an aquatic system when the size of the catch is too large to sample completely.     

Invasives, Introductions and Acidification: The Dynamics of a Stressed River Fish Community

We describe the development of the fish community in the acidified and limed river Litleåna in southern Norway, and describe how chemical restoration, compensatory introductions of exotics, and accidental invasion of exotics interact to influence the population of the naturally occurring brown trout (Salmo trutta). The river Litleåna is a tributary to the river Kvina in Vest-Agder County, southern Norway. During the years 1996–2004, annual mean pH was 4.9–5.0 and 6.1–6.4 above and below the liming facility, which was installed in 1994. Originally, brown trout was the only fish species in the river, but brook trout (Salvelinus fontinalis) have been intentionally introduced, whereas European minnow (Phoxinus phoxinus) was introduced by accident. Fish densities were recorded by means of electrofishing annually over the ten year period 1995–2004. Although close to extinction before liming was initiated, brown trout fry densities increased from 1995 to 1999, with subsequent varying densities. There has been a simultaneous major increase in the occurrence and density of European minnow since 1997. Our results show that both brown trout and European minnow increase after liming. Minnow densities are negatively affected by low pH episodes in the river. The growth rates of brown trout fry are negatively correlated to minnow densities, indicating competition between the species. Brook trout densities have decreased since liming started, and during the brown trout recovery.     

五华区近两年医源性污水排放概况

通过分析监管医源性污水排放的重要性,并结合医源性污水的处理方法,对五华区两年来医源性污水监测数据进行比较。     

实施环境标志标准对建筑、建材行业节能减排促进作用

以中国环境标志建筑、建材标准为研究对象,介绍了中国环境标志的定义及其标准遵循的原则,介绍了环境保护部发布的环境标志标准HJ/T351-2007《生态住宅(住区)》、HJ/T296-2006《卫生陶瓷》、HJ/T297-2006《陶瓷砖》和HJ/T412-2007《预拌混凝土》的主要内容,分析了实施上述标准对建筑、建材行业节能减排的促进作用。     

吹扫捕集-GC/MS法测定水中苯系物质量控制指标研究

采用吹扫捕集-气相色谱/质谱法,通过统计全国多家实验室的测定数据和实际样品测试两种方法,对水中苯、甲苯、乙苯、间/对二甲苯、邻二甲苯、苯乙烯和异丙苯8种苯系物的平行样测定相对偏差、空白加标回收率及实际样品加标回收率3个质控指标进行了研究,分别给出每种苯系物的质控指标评价标准,提出其平行样测定相对偏差为6.5％ ～13....     

非甲烷总烃样品保存时限探讨

非甲烷总烃在监测过程中,废气样品保存容器的选择和保存时间的长短对分析结果有重要影响。研究结果表明:使用玻璃注射器保存样品,应在8 h内完成分析;使用泰德拉惰性气袋保存样品,保存时间可延长至48 h,如废气中主要组分为沸点高于150℃的高沸点化合物,则应在8 h内完成非甲烷总烃的测定。     

导电高分子固相微萃取涂层及其应用

系统地介绍了导电高分子固相微萃取涂层的特点和电化学制备方法。对常见的聚吡咯、聚苯胺和聚噻吩固相微萃取涂层及其在样品前处理中的应用作了较详细的综述。展望了导电高分子固相微萃取涂层的发展趋势。     

Optimising vegetation monitoring. A case study in A French lowland forest

Biodiversity monitoring surveys are rarely optimised statistically before being initiated. Here, we optimised the monitoring of plants in a temperate forest. The total inventory cost, the number and size of quadrats were optimised to detect a 10% change in species richness over 5 years with α = β = 0.05, using data from ongoing long-term floristic monitoring programs. The procedure showed that the inventory cost would be ca 15% lower using 100-, 200-m² quadrats instead of 300- or 400-m² quadrats. Despite the cost associated with the optimisation (e.g. gathering preliminary data) and the imprecise estimates (due to the typically small sample size of the pilot studies), optimisation would often be a better option than expert opinion when designing a monitoring survey.     

Outlier detection in phosphorus dry deposition rates measured in South Florida

Dry atmospheric deposition contributes a significant amount of phosphorus to the Everglades of South Florida. Measurement of this deposition is problematic, because samples often are contaminated to varying degrees by bird droppings and other foreign materials. This study attempted to detect and remove the outliers in phosphorus (P) flux rates measured from dry deposition samples. Visual inspection of the samples, recorded in field notes, found that 30.1% of the samples contained animal droppings and frogs. Some of the samples with droppings and frogs (2.3%) had P values greater than 884 μg P m⁻² d⁻¹ (a value twice the standard deviation of the raw data mean), and were removed from further analysis. Outlier detection statistics based on a linear regression were then used for additional data screening. Eight stations in the network of 19 were removed because high contamination precluded the use of the regression model. Of the remaining samples, 15.7% were identified through the regression procedure as contaminated and were removed. The 11 station mean for P dry deposition was 85.8±79.0 μg P m⁻² d⁻¹, prior to the regression analysis, and 74.8±75.1 μg P m⁻² d⁻¹ after removal.     

小灵猫的引种驯化技术研究

本文介绍了野生小灵猫捕捉的时间、地点和方法;提出了小灵猫的引种与驯化技术.