Evidence of reproductive disturbance in Astyanax lacustris (Teleostei: Characiformes) from the Doce River after the collapse of the Fundão Dam in Mariana,Brazil

Environmental Science and Pollution Research - The Fundão Dam collapsed, on November 5th, 2015, dumping more than 50 million/m3 of iron ore tailings, enriched with metals, into the Doce River...     

基于卫星图像的村庄真实形态评价:一种识别欧洲完整文化景观的方法

土地由中心到边缘呈现不同分布利用方式的村庄,构成了欧洲文化景观的基本单元.然而在许多的乡村景观中,那些拥有细致结构的耕地和有树木的草场的真正前工业时代的村庄正在不断失去其原有的结构,这种遗失威胁着文化的继承和生物多样性.因此,监测景观中这样的村庄真实形态的变化范围和速度是非常重要的.随着废弃时间的增加,村庄的真实形态不断丢失,我们所要研究的是怎样的丢失程度才能够通过卫星图像定量分析和目视解译进行评价.1999年,我们在波兰东南部的Bieszczady山脉开展本研究.使用1998年的陆地卫星TM数据,利用景观元素的粒度(田地大小)和土地覆盖组成(灌木和森林的扩侵)对代表真实村庄结构形态退化不同阶段的6种类型村庄进行定量描述.我们利用历史地图勾勒出村庄的边界,并测量从前森林和空地的范围.利用卫星数据,将当前的土地利用和表示成粒度及森林的扩侵状况的土地废弃程度绘制成图.退化沿着2条变化路径发生:被废弃并且最终变成森林,或者形成集约农业.为了验证这样的结果,我们通过对原始卫星影像的目视解译,将1000km2范围内的22个其他村庄分成了4类.而后,我们收集了过去60年人口变化的历史数据.村庄真实形态的分类与人口下降速度明显相关.我们希望验证和应用这种快速评估文化景观真实形态的方法能够得到重视,尤其是在随着欧盟的扩大正在经历或者将要发生巨大变化的欧洲区域.最后,我们论证了村庄具有成为一个融合自然与社会科学的景观尺度的可能性.     

Supportive Breeding and Variance Effective Population Size

The practice of supporting weak, wild populations through release of individuals bred in captivity is becoming an increasingly important conservation measure. A frequently recommended form of such breeding-release activity refers to supportive breeding: a fraction of the target population is brought into captivity for reproduction, and the resulting progeny are released to mix with the wild segment of the population. We derived an expression for the variance effective size of a population managed through supportive breeding and discuss its relationship to previously published equations that are based on the assumption of random mating. We show that the effect of supportive breeding may be quite different on the inbreeding and the variance effective sizes. Whereas supportive breeding always results in a reduction of the inbreeding effective number, the variance effective number may either decrease, increase, or remain unchanged. We discuss these observations in relation to conservation management and suggest some general guidelines for supportive breeding situations. Our recommendations include making a distinction between inbreeding and variance effective numbers; taking particular care when dealing with organisms with high reproductive potential; assuring that the amount of drift be no larger than it would be without supportive breeding; and focusing primarily on the variance effective size of a population-that is, on the effective number directly related to the rate of loss of gene diversity.     

Speciation of arsenic using solid phase extraction cartridges

Various solid phase extraction (SPE) cartridges were investigated for speciation of arsenite [As(III)], arsenate [As(v)], monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA). Cartridges containing different types of sorbent materials were tested for arsenic retention and elution characteristics. Alumina cartridges were found to completely retain all the four target arsenic species, and are suitable for removal and preconcentration purposes. For speciation analysis, different arsenic species were separated on the basis of their selective retention on and elution from specific cartridges. DMA was retained on a resin-based strong cation exchange cartridge and eluted with 1.0 M HCl. MMA and As(v) were both retained on a silica-based strong anion exchange cartridge and sequentially eluted with 60 mM acetic acid (for MMA) and 1.0 M HCl [for As(v)]. As(III) was not retained on either cartridge and remained in solution. Arsenic species in solution and those eluted from the cartridges were subsequently quantified by using flow injection with hydride generation atomic fluorescence spectrometry (FI-HGAFS) and hydride generation atomic absorption spectrometry (FI-HGAAS). A detection limit of 0.05 microg L(-1) arsenic in water sample was achieved using HGAFS. An application of the method was demonstrated at a drinking water treatment facility. As(III) and As(v) species were determined in water at various stages of treatment. The method is suitable for routine determination of trace levels of arsenic in drinking water to comply with more stringent environmental regulations.     

Assessing protected area effectiveness using surrounding (buffer) areas environmentally similar to the target area

Many studies are based on the assumption that an area and its surrounding (buffer) area present similar environmental conditions and can be compared. For example, in order to assess the effectiveness of a protected area, the land use/cover changes are compared inside the park with its surroundings. However, the heterogeneity in spatial variables can bias this assessment: we have shown that most of the protected areas in Mexico present significant environmental differences between their interior and their surroundings. Therefore, a comparison that aims at assessing the effectiveness of conservation strategies, must be cautioned. In this paper, a simple method which allows the generation of a buffer area that presents similar conditions with respect to a set of environmental variables is presented. The method was used in order to assess the effectiveness of the Calakmul Biosphere Reserve, a protected area located in the south-eastern part of Mexico. The annual rate of deforestation inside the protected area, the standard buffer area (based upon distance from the protected area only) and the similar buffer area (taking into account distance along with some environmental variables) were 0.3, 1.3 and 0.6%, respectively. These results showed that the protected area was effective in preventing land clearing, but that the comparison with the standard buffer area gave an over-optimistic vision of its effectiveness.     

One-year monitoring survey of organic compounds (PAHs, PCBs, TBT), heavy metals and biomarkers in blue mussels from the Arcachon Bay, France

Marine mussels Mytilus sp. were transplanted on a monthly basis in cages over one year to oyster farms and harbours in the Arcachon Bay (France) in order to assess the water quality of the bay. Contaminant levels (organotin compounds, trace metals, PCBs and PAHs) were measured in tissues of transplanted mussels and mussels from a reference station, along with physiological parameters of the mussels (condition indexes, lipid content and dry weight). Four biomarkers (AChE: acetylcholinesterase activity, GST: gluthathione S-transferase activity, CAT: catalase activity and TBARS: thiobarbituric acid-reactive substance content) were also monitored. The remote stations monitored (oyster parks) exhibited no accumulation pattern of pollutants. Their respective concentrations therefore constitute a background level of the contamination in the bay ([TBT]= 30 ng Sn g(-1) dw, [SigmaHAPs]= 100 ng g(-1) dw, [SigmaPCBs]= 35 ng g(-1) dw). The elevated chemical contamination of the largest harbour of the bay, the Arcachon harbour, can be interpreted in terms of persistence of organotin compounds ([SigmaOTs]= 1500-2000 ng Sn g(-1) dw) and PAHs ([SigmaHAPs]= 4500-5000 ng g(-1) dw) in sediments and, to a lesser extent, of direct inputs of copper ([Cu]= 20 microg g(-1) dw in harbours versus 7 in oyster parks) and petrogenic PAHs ([methylphenanthrenes]= 1600 ng g(-1) dw in the dockyard versus 170 at the gas stations), related to the use of copper-based antifouling paints and to dockyard activity, respectively. However, the Arcachon Bay presents a low contamination level by PCBs and metals, including harbour stations. Furthermore, higher levels of other PAHs (particularly alkyl PAHs such as methylphenanthrenes/1600 ng g(-1) dw) not included in the 16 PAHs from the EPA priority list (usually studied in biomonitoring programmes/1500 ng g(-1) dw) in the Arcachon harbour underline the need to integrate these compounds in biomonitoring of highly PAH-polluted areas such as harbours in order to avoid misinterpretation of the biological responses observed. Biomarker responses were not able to discriminate the different chemical contamination levels recorded in the Arcachon Bay and rather reflected changes in environmental factors. Furthermore, the strong intraspecies variability of biological responses could be due to genetic differences of mussels from the Arcachon Bay. It is the first time that such an integrated monitoring is performed in the Arcachon Bay, also taking into account seasonal variations of chemical contents and biomarkers levels in mussel tissues.     

Interlaboratory evaluation of endotoxin analyses in agricultural dusts--comparison of LAL assay and mass spectrometry

Endotoxin exposure is associated with wheeze and asthma morbidity, while early life exposure may reduce risk of allergy and asthma. Unfortunately, it is difficult to compare endotoxin results from different laboratories and environments. We undertook this study to determine if lipopolysaccharide (LPS) extraction efficiency could account for differences among laboratories. We generated and collected aerosols from chicken and swine barns, and corn processing. We randomly allocated side-by-side filter samples to five laboratories for Limulus assay of endotoxin. Lyophilized aliquots of filter extracts were analyzed for 3-hydroxy fatty acids (3-OHFAs) as a marker of LPS using gas chromatography-mass spectrometry. There were significant differences in endotoxin assay and GC-MS (LPS) results between laboratories for all dust types (p < 0.01). Patterns of differences between labs varied by dust type. Relationships between assay and GC/MS results also depended on dust type. The percentages of individual 3-OHFA chain lengths varied across labs (p < 0.0001) suggesting that each lab recovered a different fraction of the LPS available. The presence of large amounts of particle associated LPS and absence of a freezing thawing cycle were associated with lower correlations between LPS and bioactivity, consistent with an absence of Limulus response to cell-bound endotoxin. These data suggest that extraction methods affect endotoxin measurements. The LAL methods may be most suitable when comparing exposures within similar environments; GC-MS offers additional information helpful in optimizing sample treatment and extraction. GC-MS may be of use when comparing across heterogeneous environments and should be considered for inclusion in future studies of human health outcomes.