莱州湾东部海域多溴联苯醚的污染特征及生态风险评价

于2015年4月和11月,在莱州湾东部海域设置6个采样站点,采集海水和表层沉积物样品,采用气相色谱-质谱联用联用测定海水溶解相、颗粒相和沉积物中14种多溴联苯醚(PBDEs)的含量,分析了PBDEs的组成特征,采用主成分分析了其来源,并对其生态风险进行了评价.结果表明,4月份溶解相、颗粒相和表层沉积物中14种PBDEs同系物总含量(∑14PBDEs)的范围分别为0. 29—0. 76 ng·L~(-1)、1.79—3.60 ng·L~(-1)和31.37—44. 39 ng·g-1,其中BDE209的含量范围分别为0. 21—0. 65 ng·L~(-1)、0.84—2.34 ng·L~(-1)和24. 27—36.79 ng·g-1.11月份海水溶解相和沉积相中∑14PBDEs与4月份无显著差异(P 0. 05),但颗粒相中的∑14PBDEs显著低于4月份(P0.05).4、11月颗粒相中∑14PBDEs占海水中总含量(溶解相+颗粒相)的平均比例分别为83.9%和71.2%,表明PBDEs主要分配在颗粒相上.沉积物PBDEs含量与总有机碳呈极显著正相关关系(r0.9,P0.01).14种PBDEs中,BDE209是最主要的同系物,其次是BDE47.主成分分析表明,莱州湾PBDEs主要来源于商业十溴联苯醚的地表径流输入.莱州湾东部海水中五溴联苯醚和八溴联苯醚存在低生态风险,沉积物中五溴联苯醚具有中等生态风险.     

喜马拉雅山区葇籽草和棘豆样品中PCBs、PBDEs和PCDD/Fs的分析

应用同位素稀释-高分辨气相色谱/高分辨质谱(HRGC/HRMS)法分析了喜马拉雅山区海拔5000 m以上的葇籽草和棘豆样品中多氯联苯(PCBs)、多溴联苯醚(PBDEs)和二噁英(PCDD/Fs)的含量.这两种植物样品中污染物含量与世界其它偏远地区的水平基本保持一致.其中PCBs的总含量在1.94—3.62 ng.g-1干重(dw)范围内,平均值为2.60 ng.g-1dw;PCB-28和PCB-52的浓度明显较高,约占7种指示性PCBs总量的90%以上.14种PBDEs的总浓度在83.3—142 pg.g-1dw之间,平均值为116 pg.g-1dw;除BDE-85、-138、-154,以及高溴代的BDE-190和BDE-209未检出外,其它9种单体均有不同程度的检出,且以低溴代的BDE-28为主,含量占45%以上.样品中PCDD/Fs基本上未检出.由于样品采集点位于喜马拉雅山人迹罕至的珠穆朗玛峰北坡地区,周围并无工业污染源,因此植物样品中PCBs及PBDEs可能是污染物发生大气长距离传输和生物富集的结果.     

BDE-209和PCB153在致大鼠肝细胞DNA蛋白质交联(DPC)上的拮抗作用

多溴联苯醚(PBDEs)和多氯联苯(PCBs)都是为人熟知的持久性有机污染物,也同为室内半挥发性有机物(SVOcs).由于二者结构类似,通常认为PBDEs具有和PCBs相似的毒性.染毒剂BDE-209和PCB153分别是PBDEs和PCB家族的主要同系物,并且同时存在于环境和人体组织中.实验以DNA蛋白质交联(DPC)...     

渤海湾南排河海域脉红螺中多氯联苯的污染特征

本文利用气相色谱-质谱/质谱测定了渤海湾南排河海域野生脉红螺肌肉组织中多氯联苯(PCBs)的含量,并对其污染特征进行讨论.结果表明:(1)肌肉中多氯联苯(∑PCBs)总浓度在8.40—10.06 ng.g-1(lw,以脂肪质量计)之间,其中PCB-114含量最高(0.74—1.06 ng.g-1(lw));(2)五氯联苯和六氯联苯为主要检出组分,占∑PCBs的43.7%—84.8%;(3)雌性脉红螺个体中PCBs的平均浓度略高于雄性及性畸变脉红螺中PCBs的平均浓度,分别为(10.06±0.89)ng.g-1(lw)、(8.40±0.63)ng.g-1(lw)和(8.51±0.67)ng.g-1(lw),但性别间无显著性差异.     

塑料企业周边水体中多溴联苯醚的污染特征

多溴联苯醚(PBDEs)是一种新型的持久性有机污染物(POPs)。采用固相萃取-气相色谱法测定了某塑料企业周边及当地自然水体中的PBDEs浓度,主要针对BDE~(-1)7、28、47、66、85、99、100、138、153、154、183、203及BDE-209共13个PBDE同系物的浓度水平、组成分布和污染特征进行分析。结果显示,使用企业周边水体中除BDE-203在水体中未检出外,其余12种PBDE同系物均有不同程度的检出。Σ13PBDEs质量范围处于未检出~363 ng·L~(-1),各同系物的平均质量浓度为未检出~42.6ng·L~(-1)。其中BDE-209为最大检出质量丰度同系物,但其检出率仅为25.0%,检出率较高的同系物是BDE~(-1)7、BDE-28和BDE~(-1)00,检出率分别为75.0%、75.0%、58.3%,低溴代联苯醚的检出率显著高于高溴代联苯醚。当地自然水体中13种PBDEs均有不同程度的检出,检出浓度在0.161~1.83 ng·L~(-1)。企业周边水体中PBDEs的污染水平显著高于自然水体,是自然水体浓度的5~100倍。因此,企业周边区域水体中PBDEs的污染情况应引起相关部门关注。     

典型灌区稻田多氯联苯残留特征及生态风险评估

以南方典型小灌区的两块稻田为试验小区,采用GC-ECD对其田间水体和土壤中EPA优控14种多氯联苯（PCBs）进行了检测和定量分析。结果表明,14种PCBs同系物有不同程度检出,优势残留物主要以3氯和5氯取代PCBs为主,水和土壤占PCBs总量的88.24%、90.13%。水中∑PCBs质量浓度为24.09～310.34ng·L^-1,其中地表水均值为245.84ng·L^-1,地下水均值为96.46ng·L^-1;土壤中∑PCBs质量分数为10.01～54.63ng·g^-1,均值为33.92ng·g^-1。稻田地表水中的PCBs质量浓度远高于地下水,垂向迁移明显但速度较慢;稻田地表及地下水中PCBs质量浓度有随时间衰减的趋势,可能与水稻的生育周期有关;淹灌处理稻田PCBs质量分数高于节水灌溉。研究区毒性当量TEQ在2.65×10^-2～7.54×10^-2pg·g^-1之间,生态风险处于中等水平。地表及地下水均遭到污染,再加上PCBs具有生态累积效应,危害不容忽视。     

电子废弃物拆解地水体多溴联苯醚分布特征

为了解和比较广东贵屿电子废弃物拆解地和珠三角城市地区水体中多溴联苯醚的种类、含量及分布特征,于2011年9月在广东贵屿周边地区和广州采集了20个地下水、7个地表水和4个珠江水,用反相C18萃取小柱提取净化后,利用气相色谱-质谱法测定了样品中的8种多溴联苯醚（PBDEs）。研究结果表明：贵屿地区地下水中PBDEs浓度总体上较高,总质量浓度范围为2.54~71.74 ng·L-1,平均为22.97 ng·L-1,各类PBDEs的检出率为25%~95%。三溴联苯醚（BDE28）、四溴联苯醚（BDE47）、五溴联苯醚（BDE99和BDE100之和）、六溴联苯醚（BDE153和BDE154之和）、七溴联苯醚（BDE183）和十溴联苯醚（BDE209）的质量浓度分布分别为nd~0.64、nd~18.43、nd~25.26、nd~13.92、nd~9.06和nd~15.60 ng·L-1。从物种上来看,分别源于四溴、五溴和十溴联苯醚产品的BDE47、BDE99和BDE209是贵屿地区地下水样中的优势同系物。通过比率P=（BDE47＋BDE99）/BDE209研究发现：低溴代联苯醚比高溴代联苯醚更易被地表径流迁移转换进入到地下水中。贵屿地区地表水中PBDEs的质量浓度范围为3.41~63.83 ng·L-1,平均总质量浓度为19.38 ng·L-1,稍低于当地地下水中PBDEs的平均总质量浓度,PBDEs的组成以高溴代的BDE209为特征,与世界其他水体研究结果相比,可以发现贵屿地区的地表水中PBDEs的平均总质量浓度明显偏高,说明该地区的地表水受到较严重的PBDEs污染,必须引起足够的重视。珠江水中PBDEs的总质量浓度范围为3.48~20.84 ng·L-1,平均为10.39 ng·L-1,表明近年来珠江水体中PBDEs污染有逐渐恶化的趋势。     

气相色谱-负化学离子源-质谱法分析母乳中多溴联苯醚

多溴联苯醚(PBDEs)是一种广泛使用的含溴阻燃剂.它和多氯联苯(PCBs)是一类具亲脂性、生物难降解性和高富集性的有机污染物,对人体健康具有一定的危害.     

中国主要沿海地区鱼/贝类中PBDEs暴露水平现状、特征和发展趋势

多溴联苯醚(polybrominated diphenyl ethers,PBDEs)是一种溴代阻燃剂,稳定性强,并具有生物蓄积性和长距离迁移特性.海洋环境是疏水性PBDEs的全球汇集点,自本世纪初研究者在海洋生物中陆续发现了PBDEs.本文分析了近16年来我国环渤海,东部沿海及南海北部三个沿海地区鱼/贝类中PBDEs的暴露水平现状及分布特征.现有的研究结果表明:环渤海、东部沿海以及南海北部地区鱼类中PBDEs总体暴露含量差异显著,分别为0.56—215.81 ng·g~(-1)lw(脂重)、ND—77.0 ng·g~(-1)lw和ND—167 ng·g~(-1)lw;贝类样品PBDEs含量最高为渤海莱州湾地区230—720 ng·g~(-1)lw,其次是浙江台州地区58.33—78.98 ng·g~(-1)dw(干重);渤海沿岸鱼类中PBDEs浓度呈现上升的趋势,南海北部鱼类中的PBDEs浓度呈下降趋势,东部沿海地区鱼类体内PBDEs浓度没有明显变化;3个沿海区鱼类中PBDEs的同系物暴露特征总体表现为低溴代的PBDE-47检出率最高、对总量贡献率最大.高溴代的PBDE-209近年来在某些鱼/贝类中的检出率和检出浓度有上升趋势.     

北江沉积物中多溴联苯醚的含量水平和分布特征

多溴联苯醚(PBDEs)具有与多氯联苯(PCBs)相似的化学结构和环境行为,是一种典型的持久性有机污染物(POPs).本文研究了珠江第二大水系北江流域沉积物中PBDEs的含量水平、空间分布特征和可能来源.     

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.     

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.     

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.     

Parasitic wasps orient to green leaf volatiles

Summary Undamaged plants emit low levels of green leaf volatiles (GLVs), while caterpillar-damaged and artificially damaged plants emit relatively higher levels of certain GLVs. Female braconid parasitoids,Microplitis croceipes, oriented to both damaged plants and to individual GLVs in no-choice tests in a wind tunnel, but seldom oriented to undamaged plants. Female ichneumonid parasitoids,Netelia heroica, also oriented to individual GLVs in a wind tunnel. Males of both wasp species failed to orient to the GLVs. These data show that leaf-feeding caterpillars can cause the release of GLVs, and that parasitic wasps can respond to these odors by flying upwind (chemoanemotactic response), which brings the wasps to their caterpillar hosts. This supports the hypothesis that plants communicate with members of the third trophic level,i.e., plants under herbivore attack emit chemical signals that guide natural enemies of herbivores to sites of plant damage. In this interaction, the GLVs serve as tritrophic plant-to-parasitoid synomones. That parasitoids from two different wasp families oriented to GLVs suggests that the response may be widespread among the Hymenoptera.Mention of a commercial or proprietary product does not constitute an endorsement by the U.S. Department of Agriculture     

Potential for Electropositive Metal to Reduce the Interactions of Atlantic Sturgeon with Fishing Gear

Atlantic sturgeon (Acipenser oxyrhynchus) populations have been declared either endangered or threatened under the U.S. Endangered Species Act. Effective measures to repel sturgeon from fishing gear would be beneficial to both fish and fishers because they could reduce both fishery‐associated mortality and the need for seasonal and area closures of specific fisheries. Some chondrostean fishes (e.g., sturgeons and paddlefishes) can detect weak electric field gradients (possibly as low as 5 Μv/cm) due to arrays of electroreceptors (ampullae of Lorenzini) on their snout and gill covers. Weak electric fields, such as those produced by electropositive metals (typically mixtures of the lanthanide elements), could therefore potentially be used as a deterrent. To test this idea, we recorded the behavioral responses of juvenile Atlantic sturgeon (31–43 cm fork length) to electropositive metal (primarily a mixture of the lanthanide elements neodymium and praseodymium) both in the presence and absence of food stimuli. Trials were conducted in an approximately 2.5 m diameter × 0.3 m deep tank, and fish behaviors were recorded with an overhead digital video camera. Video records were subsequently digitized (x, y coordinate system), the distance between the fish and the electropositive metal calculated, and data summarized by compiling frequency distributions with 5‐cm bins. Juvenile sturgeon showed clear avoidance of electropositive metal but only when food was present. On the basis of our results, we conclude that the electropositive metals, or other sources of weak electric fields, may eventually be used to reduce the interactions of Atlantic sturgeon with fishing gear, but further investigation is needed. El Potencial del Metal Electropositivo para Reducir las Interacciones del Esturión Atlántico con Instrumentos de Pesca Bouyoucos, Bushnell & Brill 13–003     

The role of time and species identities in spatial patterns of species richness and conservation

Many conservation actions are justified on the basis of managing biodiversity. Biodiversity, in terms of species richness, is largely the product of rare species. This is problematic because the intensity of sampling needed to characterize communities and patterns of rarity or to justify the use of surrogates has biased sampling in favor of space over time. However, environmental fluctuations interacting with community dynamics lead to temporal variations in where and when species occur, potentially affecting conservation planning by generating uncertainty about results of species distribution modeling (including range determinations), selection of surrogates for biodiversity, and the proportion of biodiversity composed of rare species. To have confidence in the evidence base for conservation actions, one must consider whether temporal replication is necessary to produce broad inferences. Using approximately 20 years of macrofaunal data from tidal flats in 2 harbors, we explored variation in the identity of rare, common, restricted range, and widespread species over time and space. Over time, rare taxa were more likely to increase in abundance or occurrence than to remain rare or disappear and to exhibit temporal patterns in their occurrence. Space–time congruency in ranges (i.e., spatially widespread taxa were also temporally widespread) was observed only where samples were collected across an environmental gradient. Fifteen percent of the taxa in both harbors changed over time from having spatially restricted ranges to having widespread ranges. Our findings suggest that rare species can provide stability against environmental change, because the majority of species were not random transients, but that selection of biodiversity surrogates requires temporal validation. Rarity needs to be considered both spatially and temporally, as species that occur randomly over time are likely to play a different role in ecosystem functioning than those exhibiting temporal structure (e.g., seasonality). Moreover, temporal structure offers the opportunity to place management and conservation activities within windows of maximum opportunity.     

Main nutrient compounds in food bodies of Mexican <Emphasis Type="Italic">Acacia</Emphasis> ant-plants

Summary. Myrmecophytic plants use obligate ant mutualists as a constitutive indirect defence mechanism. These plants often produce cellular food bodies (FBs) to nourish their resident ants. Lipids, proteins, and even highly specialised compounds such as glycogen have been reported from FBs, but detailed chemical analyses of FB composition have so far been presented only for Southeast Asian Macaranga and Central American Piper myrmecophytes. Here we report the chemical composition of FBs of five myrmecophytic Acacia (Fabaceae) species from Mexico using HPLC (carbohydrates and proteins) and GC-MS (lipids). Feeding experiments revealed no hints on any use of external food sources by the inhabiting Pseudomyrmex ants. These ants obviously rely completely on FBs and extrafloral nectar provided by their hosts. The total content of nutrients in Acacia FBs was 15-25% of FB dry mass, being much lower than in Macaranga or Piper FBs. Proteins were dominating (8-14 % dm) in Acacia FBs and thus were present in higher amounts than in Macaranga FBs, yet in lower amounts than in Piper. Lipids contributed 1-9 % of dry mass, showing a lower proportion than in FBs of Macaranga or Piper. Carbohydrates made up 3-11 % dm, reaching in most Acacia species the same range as observed in Macaranga and in Piper FBs. Water content was 18-24 % of FB fresh mass, and structural tissue obviously made up a much higher proportion in Acacia FBs than in Macaranga or Piper FBs. Both characters might represent an adaptation to producing FBs unprotected at the leaf tips under dry conditions. Acacia FBs contain all amino acids and all fatty acids that are considered essential for insects, and their contents of lipids and proteins are higher than in the leaves from which they are ontogenetically derived. This indicates a putatively adaptive enrichment of nutritionally valuable compounds in structures functioning as ant-food.     

Examining the uncertain origin and management role of martens on Prince of Wales Island,Alaska

Conservation biologists are generally united in efforts to curtail the spread of non‐native species globally. However, the colonization history of a species is not always certain, and whether a species is considered non‐native or native depends on the conservation benchmark. Such ambiguities have led to inconsistent management. Within the Tongass National Forest of Alaska, the status of American marten (Martes americana) on the largest, most biologically diverse and deforested island, Prince of Wales (POW), is unclear. Ten martens were released to POW in the early 1930s, and it was generally believed to be the founding event, although this has been questioned. The uncertainty surrounding when and how martens colonized POW complicates management, especially because martens were selected as a design species for the Tongass. To explore the history of martens of POW we reviewed other plausible routes of colonization; genetically and isotopically analyzed putative marten fossils deposited in the late Pleistocene and early Holocene to verify marten occupancy of POW; and used contemporary genetic data from martens on POW and the mainland in coalescent simulations to identify the probable source of the present‐day marten population on POW. We found evidence for multiple routes of colonization by forest‐associated mammals beginning in the Holocene, which were likely used by American martens to naturally colonize POW. Although we cannot rule out human‐assisted movement of martens by Alaskan Natives or fur trappers, we suggest that martens be managed for persistence on POW. More generally, our findings illustrate the difficulty of labeling species as non‐native or native, even when genetic and paleo‐ecological data are available, and support the notion that community resilience or species invasiveness should be prioritized when making management decisions rather than more subjective and less certain conservation benchmarks.