长江口崇明渔港表层沉积物中丁基锡赋存特征及生态风险

在长江口及崇明岛沿岸渔港采集表层沉积物样品,通过超声萃取-乙基化衍生技术提取沉积物中的丁基锡化合物,用气相色谱-质谱联用仪分析沉积物中的丁基锡赋存特征。结果显示,在长江口的参考点沉积物中均未发现有机锡化合物,而在各调查的渔港沉积物中均检出丁基锡,总浓度在1.6~58.8 ng Sn·g-1(干重,以下同)之间变化。表层沉积物的三丁基锡(TBT)、二丁基锡(DBT)和一丁基锡(MBT)浓度范围分别为ND~28.7 ng Sn·g-1,ND~22.1 ng Sn·g-1,1.6~8 ng Sn·g-1。其中,堡镇港TBT污染水平最高;老滧港和奚家港口门处沉积物中TBT浓度与新河港差不多(平均为17.2 ng Sn·g-1),而在港口内部沉积物中均未检出TBT,仅有MBT残存。检出TBT的样点,均在大型渔船码头、客运游艇码头或船厂附近,其浓度均超过澳大利亚和新西兰推荐的TBT沉积物质量基准(ISQG)触发值,即5 ng Sn·g-1。同时各样点暴露浓度(PECsed)与预测无效应浓度(PNECsed)的商值均大于1,SQG和PECsed/PNECsed两个方面均反映了崇明岛渔业港口沉积物中的TBT存在生态风险。综上,长江口地区沉积物中有机锡化合物形态和浓度差异很大,码头或船厂附近沉积物中有机锡污染问题值得优先关注。     

水中丁基锡化合物的气相色谱分析

本文介绍了一种测定水中痕量三丁基锡和二丁基锡化合物的方法。二氯甲烷萃取和硼氢化钠氢化同时进行，用ＯＶ－１０１色谱柱分离，火焰光度检测器测定，方法最低检测浓度，三丁基锡为０．１ｐｐｂ，二丁基锡为０．４ｐｐｂ。测得青岛、上海和大连港口海水中有三丁基锡化合物存在。     

香港海域翡翠贻贝(Perna viridis L.)中多氯联苯的研究

用气相色谱 毛细管双柱 电子捕获检测器研究了香港海域翡翠贻贝中多氯联苯(PCBs)的含量及其分布特征 ,结果表明 ,翡翠贻贝体内PCBs的污染现状与香港周边污染状况相符 ,在香港某些海域中翡翠贻贝体内PCBs有较高的含量 ,特别是靠近香港陆地的海域 ,PCBs总浓度最高达 3 0 3ng·g- 1 (干样 ) .PCBs同系物的分布亦有明显的不同特征 .运用二恶英毒性当量 (TEQ)表征翡翠贻贝中PCBs的毒性 ,TEQ最高值达 4 96ng·kg- 1 ,低于美国FDA允许值     

海河流域和渤海湾沉积物和水样中五氯酚的分布

建立了水和沉积物中五氯酚(PCP)的LC-ESI-MS分析方法,并调查了海河流域以及渤海湾水体和沉积物中PCP的污染状况.海河流域中水和沉积物中PCP的浓度分别为1800ng·l-1和13700ng·g-1,最高浓度发生在万年桥.渤海湾水中PCP的平均浓度为56.8ng·l-1,高于海河流域(除万年桥)PCP的浓度水平(10.0ng·l-1),但是沉积物中PCP的平均浓度为6.58ng·g-1,远低于海河流域沉积物中PCP的浓度水平(1500ng·g-1).     

基于被动采样技术的水体中有机锡污染筛查取证研究

将三油酸甘油酯-醋酸纤维素复合膜(TECAM)用作被动采样器,开展水体中一甲基锡(MMT)、二甲基锡(DMT)、一丁基锡(MBT)、二丁基锡(DBT)、三丁基锡(TBT)、二苯基锡(DPhT)和三苯基锡(TPhT)等7种有机锡氯化物的富集实验,膜样品经甲醇/醋酸溶液提取、乙基化衍生和正己烷萃取等前处理后,用气相色谱-质谱法(GC-MS)进行定性和定量检测,得到水体中痕量有机锡污染的相关指纹信息。结果表明,7种目标化合物均可在TECAM膜上富集,48 h后均可达到平衡状态;有机锡富集能力差异较大,其TECAM膜/水分配系数(log KTECAM)与其辛醇-水分配系数(log Kow)呈现显著正相关性(r=0.97, n=7)。甲基锡富集能力较低,但可定性筛查;而苯基锡和丁基锡等5种目标化合物在TECAM膜上的被动采样速率在0.06～0.16 L·g~(-1)·d~(-1)范围变化,经反演所得其在水体中的时间加权平均浓度与传统的主动采样法所得浓度没有显著差异(P0.05)。因此,基于TECAM被动采样技术可以实现水体中极性范围较广的痕量有机锡污染筛查取证。     

天津市土壤多环芳烃污染特征、源解析和生态风险评价

采用气相色谱-质谱联机方法(GC-MS)分析了天津市不同功能区10个采样点表层土壤样品中16种多环芳烃(PAHs)的浓度,并对其污染特征、来源和生态风险进行了分析.结果表明:天津市土壤中16种多环芳烃的总浓度(∑PAHs)范围为142—1.49×103ng·g-1,平均浓度765 ng·g-1,Bap浓度范围7.06—118 ng·g-1,平均值37.6 ng·g-1.∑PAHs浓度均值呈工业区近郊区城区远郊区趋势.采用PAHs成分谱、污染物的特征比值和主成分分析的污染来源解析结果表明:工业区PAHs主要来源于焦化、煤和天然气的燃烧,以及机动车的污染排放;城区和郊区土壤中PAHs除来自于煤和焦炭的燃烧外,机动车污染是一个非常重要的污染源.根据荷兰土壤质量标准,所有采样点均有PAHs单体超标,其中西青、津南、北辰、汉沽、塘沽和大港采样点超过荷兰土壤标准规定的10种多环芳烃的苯并(a)芘(Bap)毒性当量浓度(TEQ Bap10)限值33 ng·g-1,说明天津近郊区和工业区土壤已受到PAHs的污染,存在潜在的生态风险.     

五种不同养殖生物中氯化二苯并二噁英和呋喃的污染水平及特征

对五种养殖生物进行二噁英类化合物污染水平和指纹特征的研究结果显示,鱼、虾、蟹、扇贝和牡蛎的平均浓度分别是0.35pg·g-1,0.57pg·g-1,0.62pg·g-1,0.11pg·g-1和1.38pg·g-1.OCDD是五种养殖生物的最主要污染物,其次是2,3,7,8-TCDF, 1,2,3,4,6,7,8-HpCDD和OCDF. 1,2,3,7,8-PeCDD和2,3,4,7,8-PeCDF是五种养殖生物中二噁英毒性最主要的贡献者.初步认为,生活习性的差异是造成五种不同养殖生物二噁英污染水平差异的重要原因.     

椒江口水体和生物体中典型有机污染物的浓度水平及来源初探

研究了椒江口海水、沉积物和生物体中苯胺、硝基苯、多氯联苯、多环芳烃的浓度水平及来源,评价了各种有机污染物在沉积物和生物体内的富集情况.结果表明,椒江口海水中苯胺、硝基苯、多氯联苯(PCBs)、多环芳烃(PAHs)的浓度范围分别为9.3-105.1μg·l-1,46.2-268.5μg·l-1,57.5-519.3ng·l-1和356.9-1021.4 ng·l-1;沉积物中苯胺、多氯联苯、多环芳烃的浓度(干重)范围分别为0.76-1.12μg·g-1,5.78-10.42 ng·g-1,77.5-165.4 ng·g-1;生物体中PCBs、PAHs的浓度(湿重)范围分别为19.51-20.62 ng·g-1,0.11-1.03 ng·g-1.生物体内PCBs的富集倍数高于PAHs,而沉积物中PAHs的富集倍数高于PCBs.海水、沉积物中的苯胺和硝基苯主要来自源于椒江口化工废水的排放,PAHs主要来源于台州火力发电厂的燃烧污染,PCBs主要来源于废旧电器拆解业污染物的排放迁移.     

太湖沉积物柱状样中有机氯农药的垂直分布特征

采用气相色谱质谱法测定了太湖沉积物柱状样品中有机氯农药(OCPs)含量,探讨了沉积柱中有机氯农药的垂直变化特征及可能的来源.研究结果表明:沉积柱中OCPs浓度为0.88—4.73 ng·g-1(干重),平均值为2.17 ng·g-1;DDTs、HCHs、六氯苯的残留量均较高,其中DDTs为0.10—1.32 ng·g-1,平均值为0.57 ng·g-1;HCHs的浓度为0.25—1.99 ng·g-1,平均值为0.65 ng·g-1;六氯苯为0.50—1.35 ng·g-1,平均值为0.92 ng·g-1.3个湖湾的沉积柱表层DDTs含量最高,有明显的表面富集现象,成分分析表明,太湖可能着存在着DDTs类物质的输入.     

大型钢铁厂及其周边土壤多环芳烃污染现状调查、评价与源解析

采用气相色谱-质谱联机方法(GC-MS)分析了东北某钢铁厂及周边居住区、风景区共11个采样点表层土壤样品16种多环芳烃(PAHs),结果表明,钢铁工业区16种PAHs(∑PAHs)浓度范围为3.39×103—1.54×105ng·g-1,平均浓度3.21×104ng·g-1;居住区∑PAHs浓度范围为587—6.70×103ng·g-1,平均浓度3.82×103ng·g-1;风景区千山∑PAHs浓度385 ng·g-1.∑PAHs和Bap浓度均呈工业区>居住区>风景区趋势.与国内外其他研究结果相比,该钢铁工业区及其周边居住区土壤PAHs污染相对较为严重,11个采样点中有9个采样点土壤∑PAHs为严重污染,4个采样点苯并(a)芘(Bap)浓度超过加拿大土壤质量基准.利用特征比值法(Diagnostic Rate)和主成分分析法(Principal component analysis,PCA)对钢铁工业区及其周边地区土壤进行了源解析,结果表明,钢铁工业区土壤中PAHs主要来源于焦炉、燃煤、柴油燃烧等污染源,周边地区土壤除受工业污染源排放影响外,机动车汽油、柴油污染排放也有重要影响.     

Achieving Open Access to Conservation Science

Conservation science is a crisis discipline in which the results of scientific enquiry must be made available quickly to those implementing management. We assessed the extent to which scientific research published since the year 2000 in 20 conservation science journals is publicly available. Of the 19,207 papers published, 1,667 (8.68%) are freely downloadable from an official repository. Moreover, only 938 papers (4.88%) meet the standard definition of open access in which material can be freely reused providing attribution to the authors is given. This compares poorly with a comparable set of 20 evolutionary biology journals, where 31.93% of papers are freely downloadable and 7.49% are open access. Seventeen of the 20 conservation journals offer an open access option, but fewer than 5% of the papers are available through open access. The cost of accessing the full body of conservation science runs into tens of thousands of dollars per year for institutional subscribers, and many conservation practitioners cannot access pay‐per‐view science through their workplace. However, important initiatives such as Research4Life are making science available to organizations in developing countries. We urge authors of conservation science to pay for open access on a per‐article basis or to choose publication in open access journals, taking care to ensure the license allows reuse for any purpose providing attribution is given. Currently, it would cost $51 million to make all conservation science published since 2000 freely available by paying the open access fees currently levied to authors. Publishers of conservation journals might consider more cost effective models for open access and conservation‐oriented organizations running journals could consider a broader range of options for open access to nonmembers such as sponsorship of open access via membership fees. Obtención de Acceso Abierto a la Ciencia de la Conservación     

Rapid,recurring, structured survey versus bioblitz for generating biodiversity data and analysis with a multispecies abundance model

A bioblitz inexpensively and quickly generates biodiversity data, but bioblitzes are often conducted with haphazard, unreplicated sampling. Results tend to be taxonomically, geographically, or temporally biased, lack metadata, and consist of lists of observed taxa that do not enable further analyses or correction for imperfect detection. A rapid, recurring, structured survey (RRSS) uses a structured sampling design and temporal and spatial replication to survey randomly selected sites on a conservation property. We participated in a loosely structured bioblitz and a subsequent RRSS at Big Canoe Creek Nature Preserve in Springville (St. Clair County), Alabama (USA) to compare observed richness derived from the 2 survey approaches. The RRSS data structure enabled us to fit models that accounted for imperfect detection to estimate abundances, occupancy probabilities, and habitat associations. The loosely structured bioblitz data could not be used in such models. We present a new integrated multispecies abundance model that we applied to avian RRSS data. Our model extension enables estimation for the community, employs data augmentation to estimate the number of undetected species, and incorporates covariates. The RRSS generated a more comprehensive and less biased list of observed taxonomic richness than the loosely structured bioblitz (e.g., 73 vs. 45 bird species and 104 vs. 63 insect families from the RRSS vs. loosely structured bioblitz, respectively). Models fit to the RRSS data identified seasonal patterns in avian community composition and allowed for estimation of habitat–occupancy relationships for insect taxa. The RRSS protocol has potential for broad transferability as a standardized, quick, and inexpensive way to inventory biodiversity and estimate ecological parameters while providing an outreach opportunity.     

Compliance with and ecosystem function of biodiversity offsets in North American and European freshwaters

Land-use change via human development is a major driver of biodiversity loss. To reduce these impacts, billions of dollars are spent on biodiversity offsets. However, studies evaluating offset project effectiveness that examine components such as the overall compliance and function of projects remain rare. We reviewed 577 offsetting projects in freshwater ecosystems that included the metrics project size, type of aquatic system (e.g., wetland and creek), offsetting measure (e.g., enhancement, restoration, and creation), and an assessment of the projects’ compliance and functional success. Project information was obtained from scientific and government databases and gray literature. Despite considerable investment in offsetting projects, crucial problems persisted. Although compliance and function were related to each other, a high level of compliance did not guarantee a high degree of function. However, large projects relative to area had better function than small projects. Function improved when projects targeted productivity or specific ecosystem features and when multiple complementary management targets were in place. Restorative measures were more likely to achieve targets than creating entirely new ecosystems. Altogether the relationships we found highlight specific ecological processes that may help improve offsetting outcomes.     

Some polyphagous Homoptera gain protection from their natural enemies by feeding on the toxic plantsSpartium junceum andErythrina corallodendrum (Leguminosae)

Summary Interactions were studied among alkaloid-containing legumes (Erythrina corallodendrum andSpartium junceum) and non-toxic plants (Citrus sinensis, Cucurbita moschata andEuphorbia tirucalli), several polyphagous homopterans,Aphis craccivora (Aphididae),Icerya purchasi, I. aegyptiaca (Margarodidae),Lepidosaphes ulmi (Diaspididae) andPlanococcus citri (Pseudococcidae), and some major natural enemies of these homopterans. Significant reductions in survival due to negative effects of alkaloid containing as compared with non-alkaloidal plants were recorded for the predatorsRodolia cardinalis andChilocorus bipustulatus, but not forCryptolaemus montrouzieri (Coleoptera: Coccinellidae),Chrysoperla carnea (Neuroptera: Chrysopidae) andSympherobius sanctus (Neuroptera: Sympherobiidae). The development time of the larvae or pupae ofR. cardinalis, C. carnea andS. sanctus was longer on the toxic plants than on the non-toxic ones. The percentage of parasitism ofA. craccivora collected from the non-alkaloidal plantsVicia palaestina andMelilotus albus was much higher than that onS. junceum. The parasitoid complexes ofA. craccivora differed between both plant groups. The nutritive value of honeydew ofI. purchasi andA. craccivora, as expressed by the life span ofEncyrtus infelix (Hymenoptera: Encyrtidae) adults, was also investigated. Life spans were significantly longer when the wasps fed on honeydew produced on non-alkaloidal plants (C. sinensis andPittosporum tobira) than on alkaloid containing plants whenI. purchasi — but notA. craccivora — was the producer. It is suggested that the chemical defense ofE. corallodendrum andS. junceum is exploited by polyphagous phytophages to reduce predation. In nature, population growth and density of four of the investigated homopterans are conspicuously high when they developed on the alkaloid containing plant species, and very low on non-alkaloid plants. The efficiency of their natural enemies may be reduced by sequestration of alkaloids (or other toxic plant compounds) or their transfer into excreted honeydew. Therefore it is assumed that a generalist phytophagous homopteran may be protected from its natural enemies, although at different rates of efficiency, if it can safely sequester the host allelochemical when it develops on toxic species within its host range.     

A palaeo-hydrogeological model for arsenic contamination in southern and south-east Asia

An argument is presented in which areas of natural arsenic contamination of modern groundwaters throughout Asia have a common origin. Arsenic originally accumulated in oceanic ferro-manganoan sediments of the eastern Palaeo-Tethys. This was further concentrated through oceanic crustal extinction in what later became the south-east Chinese accreted mineralised terrain. Proto-Himalayan uplift of this area created the palaeo-drainage systems of the Ganges – Brahmaputra, Irrawaddy, Mekong, and Red Rivers, with consequent headwater erosion of arsenic-rich sediments. Their downstream deposition as immature and easily redistributed Neogene sandstones, silts, and iron-rich clays has created secondary and tertiary reservoirs of adsorbed and authigenic arsenic, from which the current arsenic-rich groundwaters have evolved. Considering river basins within the above palaeo-hydrogeological framework provides a basis for assessing the risk of arsenic in groundwater basins of south and south-eastern Asia.     

Sequestration of cucurbitacin analogs by New and Old World chrysomelid leaf beetles in the tribe Luperini

Summary Two South American polyphagous leaf beetles,Diabrotica speciosa andCerotoma arcuata, selectively accumulated the bitter tasting compound 23,24-dihydrocucurbitacin D in their body after ingesting root tissues of cucurbit plants. Similarly, three Asian Cucurbitaceae-feeding specialists in the genusAulacophora were found to sequester the same compound. Cucurbitacin analogs were shown to deter feeding by a bird predator, indicating an allomonal role for these compounds in cucurbitacin-associated chrysomelid leaf beetles both of New and Old Worlds. The strong affinity to cucurbitacins, selective sequestration of the analogs and consequent protection from predators suggested an ecological adaptation mechanism developed in common among these two geographically isolated subtribes in the Luperini.     

Threats to intact tropical peatlands and opportunities for their conservation

Large, intact areas of tropical peatland are highly threatened at a global scale by the expansion of commercial agriculture and other forms of economic development. Conserving peatlands on a landscape scale, with their hydrology intact, is of international conservation importance to preserve their distinctive biodiversity and ecosystem services and maintain their resilience to future environmental change. We explored threats to and opportunities for conserving remaining intact tropical peatlands; thus, we excluded peatlands of Indonesia and Malaysia, where extensive deforestation, drainage, and conversion to plantations means conservation in this region can protect only small fragments of the original ecosystem. We focused on a case study, the Pastaza‐Marañón Foreland Basin (PMFB) in Peru, which is among the largest known intact tropical peatland landscapes in the world and is representative of peatland vulnerability. Maintenance of the hydrological conditions critical for carbon storage and ecosystem function of peatlands is, in the PMFB, primarily threatened by expansion of commercial agriculture linked to new transport infrastructure that is facilitating access to remote areas. There remain opportunities in the PMFB and elsewhere to develop alternative, more sustainable land‐use practices. Although some of the peatlands in the PMFB fall within existing legally protected areas, this protection does not include the most carbon‐dense (domed pole forest) areas. New carbon‐based conservation instruments (e.g., REDD+, Green Climate Fund), developing markets for sustainable peatland products, transferring land title to local communities, and expanding protected areas offer pathways to increased protection for intact tropical peatlands in Amazonia and elsewhere, such as those in New Guinea and Central Africa which remain, for the moment, broadly beyond the frontier of commercial development.     

Effects of Controlled Fire and Livestock Grazing on Bird Communities in East African Savannas

Abstract: In East Africa fire and grazing by wild and domestic ungulates maintain savannas, and pastoralists historically set fires and herded livestock through the use of temporary corrals called bomas. In recent decades traditional pastoral practices have declined, and this may be affecting biodiversity. We investigated the effects of prescribed fires and bomas on savanna bird communities in East Africa during the first and second dry seasons of the year (respectively before and after the rains that mark the onset of breeding for most birds). We compared abundance, richness, and community composition on 9‐ha burned plots, recently abandoned bomas, and control plots in the undisturbed matrix habitat over a 3‐year period. Generally, recently burned areas and abandoned bomas attracted greater densities of birds and had different community assemblages than the surrounding matrix. The effects of disturbances were influenced by interactions between primary productivity, represented by the normalized difference vegetation index, and time. Bird densities were highest and a greater proportion of species was observed on burned plots in the months following the fires. Drought conditions equalized bird densities across treatments within 1 year, and individuals from a greater proportion of species were more commonly observed on abandoned bomas. Yearly fluctuations in abundance were less pronounced on bomas than on burns, which indicate that although fire may benefit birds in the short term, bomas may have a more‐lasting positive effect and provide resources during droughts. Several Palearctic migrants were attracted to burned plots regardless of rainfall, which indicates continued fire suppression may threaten their already‐declining populations. Most notably, the paucity of birds observed on the controls suggests that the current structure of the matrix developed as a result of fire suppression. Traditional pastoralism appears critical to the maintenance of avian diversity in these savannas.     

Cost‐effective conservation of an endangered frog under uncertainty

How should managers choose among conservation options when resources are scarce and there is uncertainty regarding the effectiveness of actions? Well‐developed tools exist for prioritizing areas for one‐time and binary actions (e.g., protect vs. not protect), but methods for prioritizing incremental or ongoing actions (such as habitat creation and maintenance) remain uncommon. We devised an approach that combines metapopulation viability and cost‐effectiveness analyses to select among alternative conservation actions while accounting for uncertainty. In our study, cost‐effectiveness is the ratio between the benefit of an action and its economic cost, where benefit is the change in metapopulation viability. We applied the approach to the case of the endangered growling grass frog (Litoria raniformis), which is threatened by urban development. We extended a Bayesian model to predict metapopulation viability under 9 urbanization and management scenarios and incorporated the full probability distribution of possible outcomes for each scenario into the cost‐effectiveness analysis. This allowed us to discern between cost‐effective alternatives that were robust to uncertainty and those with a relatively high risk of failure. We found a relatively high risk of extinction following urbanization if the only action was reservation of core habitat; habitat creation actions performed better than enhancement actions; and cost‐effectiveness ranking changed depending on the consideration of uncertainty. Our results suggest that creation and maintenance of wetlands dedicated to L. raniformis is the only cost‐effective action likely to result in a sufficiently low risk of extinction. To our knowledge we are the first study to use Bayesian metapopulation viability analysis to explicitly incorporate parametric and demographic uncertainty into a cost‐effective evaluation of conservation actions. The approach offers guidance to decision makers aiming to achieve cost‐effective conservation under uncertainty.