低剂量微囊藻毒素MC-LR诱导罗氏沼虾肝胰腺损伤及凋亡

微囊藻毒素(microcystins, MCs)是由水华蓝藻释放出来的一种有生物活性的环庚肽化合物,具有较强的肝毒性,MC-LR是其分布最广的和毒性最强的一个亚型。罗氏沼虾(Macrobrachium rosenbergii)是我国比较重要的一个水产养殖品种,但由于养殖水体富营养化程度比较严重,常常爆发蓝藻水华,给其健康养殖带来较大的威胁,但是关于MCs对罗氏沼虾的毒性机制研究的报道较少。因此,使用环境相关浓度的MC-LR(0.5和5μg·L~(-1))处理罗氏沼虾1、2和3周,通过组织学观察、免疫组化定位、氧化应激指标测定以及荧光定量PCR技术探究养殖水体中常见浓度MCs对罗氏沼虾的毒害效应及潜在机制。研究结果表明,较高环境相关浓度(5μg·L~(-1))的MCs会在罗氏沼虾肝胰腺中显著富集,诱导氧化应激,破坏肝胰腺的形态和结构,并且破坏作用随暴露时间延长而加剧,并发生细胞凋亡。而较低浓度的MCs(0.5μg·L~(-1))对肝胰腺的影响相对较小,但是依然会诱导罗氏沼虾肝胰腺氧化应激,并且在长时间作用下也会给肝胰腺组织带来损伤。上述研究结果证明,环境相关浓度的MCs对罗氏沼虾也有一定的毒害作用,并且毒害作用呈剂量与时间依赖效应。     

低温对日本沼虾耗氧率、排氨率和Na+/K+ ATPase比活力的影响

在低温和室温条件下，测定了两种规格日本沼虾(Macrobrachium nipponens)的耗氧率、排氨率和Na^ ／K^ ATPase比活力．结果表明，低温条件下日本沼虾的耗氧率和排氨率均低于室温，且与体重呈负相关；而Na^ ／K^ ATPase比活力高于室温，且与体重呈正相关．表4参21     

曲霉菌丝球HX对偶氮染料的吸附脱色

采用富积和驯化方法选育出的曲霉菌丝球HX对不同种类染料表现出高效吸附性能，可在12h内完全吸附200mg／L的直接染料、分散染料及活性黄X-R的颜色，并且研究了碳源质量浓度、氮源质量浓度、盐度、培养条件及优化条件组合对菌丝球HX吸附活性艳红X-3B的影响，结果表明：随碳源质量浓度的增加，吸附率相应增加，质量浓度为10．0g／L以上时，72h及以上的吸附率大于92．3％；氮源质量浓度高于0．75g／L时对吸附率影响不大；随盐度增加，染料吸附率有所下降．在温度为25～35℃、染料培养基pH为5．0～7．0、供氧充足的条件下吸附率较高．在所筛选的最佳吸附条件下，菌丝球HX对活性艳红X-3B表现出了更好的吸附效果．图6表3参9     

溴氰菊酯对鱼虾的毒性与安全评价研究

通过室内试验和野外试验研究了溴氰菊酯农药对龟类和虾类的毒性、回避性和实际危害性。结果表明，溴氰菊酯对鲤鱼的ＬＣ５０（２４ｈ）为１．０μｇ／Ｌ，对日本沼虾的ＬＣ５０（３ｈ）为０．４１μｇ／Ｌ。在稻田中按规定的剂量使用溴氰菊酯农药治虫，对稻田养鱼和邻近鱼塘无危害影响；对虾类有较大的危害性。但虾类对溴氰菊酯有十分明显的回避性，在自然水域中溴氰菊酯对虾类的实际危害程度比在实验条件下要轻些。     

2种杀虫剂对日本沼虾的急性毒性

研究了毒死蜱和硫丹对日本沼虾(Macrobrachium nipponense)的毒性作用.根据预试验确定2种杀虫剂对日本沼虾的急性毒性试验浓度,测定沼虾24和48 h的半致死浓度p(LC50),在0～48 h的ρ(LC50)值范围内设定6个浓度梯度,对日本沼虾进行24 h胁迫试验以测定耗氧量和排氨量.毒死蜱和硫丹对日本沼虾的24和48 hρ(LC50)分别为5.03、2.01和8.47、4.02 μg·L-1,其安全质量浓度分别为0.096和0.272 μg·L-1,表明日本沼虾对毒死蜱的敏感性明显高于硫丹.随着2种杀虫剂浓度的逐渐升高,日本沼虾的耗氧量和排氨量均呈现下降趋势,表明日本沼虾采用相同的适应方式来抵御2种杀虫剂对其基础代谢的胁迫,表现为被动的忍耐.     

伊乐藻在冬季低温条件下对污染水体的净化效果

研究了耐寒沉水植物伊乐藻(Elodea nuttallii)在冬季低温条件下的生长状况，以及不同生物量的伊乐藻对污染水体的净化效果。在冬季水温3—7℃的低温条件下，大多数水生植物处于生长停滞期，然而实验结果表明，伊乐藻在此条件下却具有明显的生长能力，并且单位生物量的增长量最大可达0．34g；实验结果同样显示了伊乐藻在低温条件下对TN、TP和CODCr具有一定的净化效果，对TP的去除效果要比对TN和CODCr的去除效果好；从实验结果还可看出，伊乐藻在水温高于4℃时对藻类具有抑制作用，从这一点就可说明伊乐藻具有一定的克藻效应，且其抑制能力与水温有很大的关系。     

溴氰菊酯对鱼虾的毒性与安全评价研究

通过室内试验和野外试验研究了溴氰菊酯农药对鱼类和虾类的毒性，回避性和实际危害性。结果表明，溴氰菊酯对鲤鱼的ＬＣ５０（２４ｈ）为１．０μｇ／Ｌ，对日本沼虾的ＬＣ５０（３ｈ）为０．４１μｇ／Ｌ。在稻田中按规定的剂量使用溴氰菊酯农药治虫，对稻田养鱼和邻近鱼塘无危害影响，对虾类有较大的危害性。但虾类对溴氰菊酯有十分明显的回避性，在自然水域中溴氰菊酯对虾类的实际危害程度比在实验条件下要轻些。     

催化湿式氧化法处理对硝基酚钠废水的试验

以Mn-Ce-Zr-Cu复合型氧化物作为多相催化剂，采用催化湿式氧化法处理高浓度对硝基酚钠废水，考察了各种反应条件对废水处理效果的影响。结果表明：在温度220℃、压力2．5MPa、反应时间60min、催化剂加入量3g／L的条件下，COD去除率可达63．7％。经处理后的废水，BOD5／COD的比值由原来的0．016提高到0．33，从而为后续的生物降解创造了良好条件。     

罗氏沼虾养殖塘叶绿素a与水质因子的灰色关联分析

为研究罗氏沼虾养殖塘中影响叶绿素a的主要水质因子,于2011年6—10月对地处上海市金山区的某罗氏沼虾养殖场的3个养殖塘及水源的水温(T)、溶解氧(DO)、pH值、透明度、亚硝酸盐氮(NO2-N)、总氨氮(TAN)、总氮(TN)、活性磷(PO4-P)、总磷(TP)、叶绿素a和化学需氧量(CODMn)等因子进行监测,运用灰色关联分析方法分析了叶绿素a与水质因子的相互关系。结果发现,水质因子与叶绿素a的关联度由大到小依次为TN、TP、CODMn、DO、pH值、NO2-N、T、TAN、PO4-P和透明度,在罗氏沼虾养殖塘中影响叶绿素a的优势因子依次为TN、TP、CODMn、DO和pH值,通过进一步讨论分析发现,TN和TP是影响池塘叶绿素a最重要的水质因子。     

内河螺蛳（Margaryamelanioides）对水环境中邻苯二甲酸酯类的富集

为探索内河底栖生物对水环境中PAEs的富集规律,采用气相色谱质谱法定量测定宁波城市内河回龙段水体、底泥、螺蛳肉与壳中DMP、DEP、DIPP、DPP、DBP、BBP、DEHP和DOP的浓度。结果表明研究河域底泥、水样、螺蛳（Margaryamelanioides）肉和螺壳样品主要存在DMP、DBP、DEHP3种PAEs,DMP的平均浓度分别为3．435μg／g、0．023μg／g、1．239μg／g和0．712μg／g,DBP为2．613μg／g、0．484μg／g、6．984μg／g和0．282μg／g;DEHP为13．891μg/g、0．030μg／g、4．938μg／g和0．156μg／g,∑PAEs表现为底泥〉螺蛳肉〉螺壳〉水样。螺蛳肉及螺蛳壳对酯类富集能力分别表现为DEHP〉DBP〉DMP,DMP〉DEHP〉DBP,且螺蛳肉的富集能力明显强于螺蛳壳。螺蛳肉与水样DMP浓度呈显著的正相关,DBP和DEHP不相关;螺蛳壳中3种PAEs均与采样位点水样的PAEs呈显著的相关性;螺蛳肉、螺蛳壳与底泥的PAEs浓度均呈显著的相关性;各位点的螺蛳肉与螺蛳壳富集的3种PAEs浓度均呈显著的正相关。     

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.     

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.     

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     

Human Influence and Classical Biogeographic Predictors of Rare Species Occurrence

Biogeographic theory predicts that rare species occur more often in larger, less‐isolated habitat patches and suggests that patch size and connectivity are positive predictors of patch quality for conservation. However, in areas substantially modified by humans, rare species may be relegated to the most isolated patches. We used data from plant surveys of 81 meadow patches in the Georgia Basin of Canada and the United States to show that presence of threatened and endangered plants was positively predicted for patches that were isolated on small islands surrounded by ocean and for patches that were isolated by surrounding forest. Neither patch size nor connectivity were positive predictors of rare species occurrence. Thus, in our study area, human influence, presumably due to disturbance or introduction of competitive non‐native species, appears to have overwhelmed classical predictors of rare species distribution, such that greater patch isolation appeared to favor presence of rare species. We suggest conservation planners consider the potential advantages of protecting geographically isolated patches in human‐modified landscapes because such patches may represent the only habitats in which rare species are likely to persist. Influencia Humana y Predictores Biogeográficos Clásicos de la Ocurrencia de Especies Raras     

Seasonal dynamics of macro-algae in the South Lake of Tunis

The macro-algae communities observed in the south lake of Tunis are characterized by the predominance of nitrophilous algae which are in the order of biomass importance:Ulva, Cladophora andEnteromorpha. We have noted seasonal changes of alga distribution. The wind appears to be one of the most important factors influencing this distribution. The total biomass reaches a maximum in the spring. Rapid decomposition of the biomass leads to a severe ecological imbalance, resulting in crises of anoxia and fish death. A restoration project has already started. It aims at removal of contaminated muds and the introduction of a new circulation system. The main objectives of this work were to collect information on the distribution and biomass of the phytobenthic communities as a first step in the constitution of a database for further comparison.     

Patterns and biases of climate change threats in the IUCN Red List

International Union for Conservation of Nature (IUCN) Red List assessments rely on published data and expert inputs, and biases can be introduced where underlying definitions and concepts are ambiguous. Consideration of climate change threat is no exception, and recently numerous approaches to assessing the threat of climate change to species have been developed. We explored IUCN Red List assessments of amphibians and birds to determine whether species listed as threatened by climate change display distinct patterns in terms of habitat occupied and additional nonclimatic threats faced. We compared IUCN Red List data with a published data set of species’ biological and ecological traits believed to infer high vulnerability to climate change and determined whether distributions of climate change‐threatened species on the IUCN Red List concur with those of climate change‐threatened species identified with the trait‐based approach and whether species possessing these traits are more likely to have climate change listed as a threat on the IUCN Red List. Species in some ecosystems (e.g., grassland, shrubland) and subject to particular threats (e.g., invasive species) were more likely to have climate change as a listed threat. Geographical patterns of climate change‐threatened amphibians and birds on the IUCN Red List were incongruent with patterns of global species richness and patterns identified using trait‐based approaches. Certain traits were linked to increases or decreases in the likelihood of a species being threatened by climate change. Broad temperature tolerance of a species was consistently related to an increased likelihood of climate change threat, indicating counterintuitive relationships in IUCN assessments. To improve the robustness of species assessments of the vulnerability or extinction risk associated with climate change, we suggest IUCN adopt a more cohesive approach whereby specific traits highlighted by our results are considered in Red List assessments. To achieve this and to strengthen the climate change‐vulnerability assessments approach, it is necessary to identify and implement logical avenues for further research into traits that make species vulnerable to climate change (including population‐level threats).