Environmental change as a cause of natterjack toad (Bufo calamita) declines in Britain

An investigation was made into factors which have influenced the decline of natterjack toads Bufo calamita in Britain over the last 40 years. Natterjacks are limited in Britain to two types of habitats, coastal dunes and inland heaths. By comparing the relative declines of the species on these two habitats with other changes which have occurred on them, it became clear: (1) That Bufo calamita has declined much more extensively on heaths than on dunes: (2) that this selective decline cannot be attributed to climatic changes, public pressure or direct development; (3) that large-scale changes in the flora of heathland areas have occurred concurrently with natterjack declines. These changes, which in general have not been reflected on dunes, have occurred subsequent to altered patterns of land use on the heathlands. Cessation of grazing and increased forestry activity have permitted widespread encroachment by tall vegetation, which creates shade, both changes being directly undesirable for natterjacks, and more importantly, enabling the common toad Bufo bufo to enter as a successful competitor. This latter factor is thought to have been one of the most important causes of natterjack declines on heathland.     

Environmental Degradation at a Public Park in Southern Brazil as Revealed Through a Genotoxicity Test (MN) on Peripheral Blood Cells from Poecilia vivipara (Teleostei)

The effects of anthropogenic activities on water, environment, and consequently quality of life can be evaluated using genetic, biochemical, and microbiological parameters. Regarding genetic parameters, the micronucleus test is a fast, efficient, inexpensive method for detecting alterations in genetic material induced by a variety of genotoxic agents. In the present study, blood cells from Poecilia vivipara from the Belém River in the city of Curitiba, Paraná, Brazil were evaluated for genotoxic effects stemming from human-produced pollution, as expressed by the micronucleus. The water in the river was evaluated with regard to physiochemical and microbiological parameters as well as for heavy metals. The analysis revealed the presence of copper, zinc, and nickel, with high concentrations of copper. The micronucleus analysis revealed significant differences in relation to the groups (study and control), suggesting a positive relation between the water quality of the Belém River and micronucleus expression as a result of the pollution to which this river is subjected.     

Characteristics of Perennial Wheatgrass (Thinopyrum intermedium) and Refined Wheat Flour Blends: Impact on Rheological Properties

Intermediate wheatgrass (IWG) (Thinopyrum intermedium) is a perennial grass with desirable agronomic traits and positive effects on the environment. It has high fiber and protein contents, which increase the interest in using IWG for human consumption. In this study, IWG flour was blended with refined wheat at four IWG‐to‐wheat ratios (0:100, 50:50, 75:25, and 100:0). Samples were analyzed for proximate composition, microstructure features, pasting properties (Micro Visco‐Amylo‐Graph device), protein solubility, and total and accessible thiols. Gluten aggregation properties (GlutoPeak tester) and mixing profile (Farinograph‐AT device) were also evaluated. IWG flour enrichment increased the pasting temperature and decreased the peak viscosity of blended flours. IWG proteins exhibited higher solubility than wheat, with a high amount of accessible and total thiols. The GlutoPeak tester highlighted the ability of IWG proteins to aggregate and generate torque. Higher IWG flour enrichment resulted in faster gluten aggregation with lower peak torque, suggesting weakening of wheat gluten strength. Finally, the addition of IWG to refined wheat flour resulted in a decrease in dough development time and an increase in consistency, likely because of the higher levels of fiber in IWG. The 50% IWG flour enrichment represents a good compromise between nutritional improvement and maintenance of the pasting properties, protein characteristics, and gluten aggregation kinetics.     

Assessing the effects of marine protected area (MPA) on a reef fish assemblage in a northwestern Mediterranean marine reserve: Identifying community-based indicators

Marine protected areas (MPAs) are increasingly envisaged as a tool to manage coastal ecosystems and fisheries. Assessment of their performance with respect to management objectives is therefore important. A number of MPAs provided conservation benefits for fished species. Observed benefits do not apply to all species at all times, and responses to protection are also highly variable among fish taxa. Among the many empirical studies on marine reserves, only a few designs considered ‘before and after data’ and spatial variation. In this paper, we are interested in assessing the effect of a no-take reserve on the reef fish assemblage in a northwestern Mediterranean example. Data were obtained from a three-year survey using underwater visual censuses (UVC), before and after MPA establishment. Permutational multivariate analysis of variance (PERMANOVA) and multivariate regression trees (MRT) were used to evaluate the effects of reserve protection on the reef fish assemblage, while accounting for habitat. Modelled biological responses were abundances and diversity indices calculated at different levels of the assemblage. Significant effects were found for many of these metrics. In addition to PERMANOVA, univariate models provided more insight into the magnitude and direction of effects. The most sensitive metrics were related to large species and species targeted by fishing. These results may be used to choose the metrics that are more suitable as community-based indicators of MPA impact in the perspective of monitoring programs.     

Avian Urine: Its Potential as a Non-Invasive Biomonitor of Environmental Metal Exposure in Birds

Current non-invasive biomonitoring techniques to measure heavy metal exposure in free ranging birds using eggs, feathers and guano are problematic because essential metals copper (Cu) and zinc (Zn) deposited in eggs and feathers are under physiological control, feathers accumulate metals from surface contamination and guano may contain faecal metals of mixed bioavailability. This paper reports a new technique of measuring lead (Pb), Cu and Zn in avian urate spheres (AUS), the solid component of avian urine. These metal levels in AUS (theoretically representing the level of metal taken into the bloodstream, i.e. bioavailable to birds) were compared with levels in eggs (yolk and shell), feathers and whole guano from chickens (Gallus gallus domesticus) exposed to a heavy metal-contaminated soil (an allotment soil containing Pb 555?mg?kg^?1 dry mass (dm), Cu 273?mg?kg^?1?dm and Zn 827?mg?kg^?1?dm). The median metal levels (n?=?2) in AUS from chickens exposed to this contaminated soil were Pb 208???g?g^?1 uric acid, Cu 66???g?g^?1 uric acid and Zn: 526???g?g^?1 uric acid. Lead concentrations in egg yolk and shell samples (n?=?3) were below the limit of detection (<2?mg?kg^?1), while Cu and Zn were only consistently detected in the yolk, with median values of 3 and 70?mg?kg^?1 (dm), respectively, restricting the usefulness of eggs as a biomonitor. Feathers (n?=?4) had median Pb, Cu and Zn levels respectively of 15, 10 and 140?mg?kg^?1 (dm), while whole guano samples (n?=?6) were 140, 70 and 230?mg?kg^?1 (dm). Control samples were collected from another chicken flock; however, because they had no access to soil and their diet was significantly higher in Cu and Zn, no meaningful comparison was possible. Six months after site remediation, by top soil replacement, the exposed chickens had median Pb, Cu and Zn levels respectively in whole guano (n?=?6) of 30, 20 and 103?mg?kg^?1 (dm) and in AUS (n?=?4) of 147, 16 and 85???g?g^?1 uric acid. We suggest the persistent high Pb level in AUS was a consequence of bone mobilised for egg production, releasing chronically sequestered Pb deposits into the bloodstream. In contrast, AUS levels of Cu and Zn (metals under homeostatic control and sparingly stored) had declined, reflecting the lower current exposure. However because pre- and post-remediation samples were measured using different methods carried out at different laboratories, such comparisons should be guarded. The present study showed that metals can be measured in AUS, but no assessment could be made of availability or uptake to the birds because tissue and blood samples were not concomitantly analysed. A major short coming of the study was the inappropriate control group, having no access to uncontaminated soil and being fed a different diet to the exposed birds. Furthermore guano and urine analysis should have been carried out on samples from individual birds, so biological (rather than just technical) variation of metal levels could have been determined. Future studies into using AUS for biomonitoring environmental heavy metals must resolve such experimental design issues.     

Environmental fate and effects of Bacillus thuringiensis (Bt) proteins from transgenic crops: a review

This paper reviews the scientific literature addressing the environmental fate and nontarget effects of the Cry protein toxins from Bacillus thuringiensis (Bt), specifically resulting from their expression in transgenic crops. Published literature on analytical methodologies for the detection and quantification of the Cry proteins in environmental matrices is also reviewed, with discussion of the adequacy of the techniques for determining the persistence and mobility of the Bt proteins. In general, assessment of the nontarget effects of Bt protein toxins indicates that there is a low level of hazard to most groups of nontarget organisms, although some investigations are of limited ecological relevance. Some published reports on the persistence of the proteins in soil show short half-lives, whereas others show low-level residues lasting for many months. Improvements in analytical methods will allow a more complete understanding of the fate and significance of Bt proteins in the environment.     

Suitability of Fly Ash Vermicompost as a Component of Pine Bark Growing Media: Effects on Media Physicochemical Properties and Ornamental Marigold (Tagetes spp.) Growth and Flowering

This study evaluated the possibility of mixing fly ash vermicompost (FA) with pine bark (PB) compost to produce a horticultural growing medium for ornamental plants using ornamental marigolds (Tagetes spp.) as the test crop. Fly ash vermicompost was mixed with pine bark compost at 0, 25, 50, 75, and 100% and marigold seeds were sown with or without fertilizer in the resultant media to test their suitability as seedling growing media. FA substitution up to 50% significantly improved water-holding capacity, total porosity, and air-filled porosity. It also raised pH from 4.52 to a maximum of 8.33 when incorporated up to 75%. Incorporation of FA up to 75% resulted in significantly high germination percentages above 90% compared to only 22.5% for the 100% PB medium. However, after 4 weeks of growth, seedlings in the 25 and 50% FA substituted media had higher plant height and leaf area. The 25% FA treatment resulted in significantly higher number of flowers and buds compared to the 50 and 75%. For effective marigold seedling germination and growth, a 50% FA:50% PB growing medium is recommended while for maturity and flower production, the 25% FA:75% PB combination is preferred.     

高效液相色谱法测定土壤中的二氯喹啉酸

用50 ml甲醇︰0.05 mol/L硼砂溶液(p H=10)(9︰1,v/v)作为提取剂对20 g(或适量)土壤样品中残留的二氯喹啉酸振荡提取2 h,离心过滤后分取滤液25 ml浓缩,甲醇定容至2 ml,再用滤膜过滤后待测定;高效液相色谱仪(HPLC)以1.0 ml/min的甲醇︰1%乙酸水溶液(55︰45,V/V)为流动相,柱温45℃,在238 nm的紫外光波长下进行二氯喹啉酸的外标法定量。该方法精密度为6.0%,检出限为0.012 mg/kg,不同类型土壤的加标回收率74.9%~98.8%,能满足有机分析要求。该方法既简捷易操作,又能满足土壤中二氯喹啉酸低残留量的测定。     

上海城市绿地土壤中石油烃化合物的分布特征

对上海不同类型绿地土壤的石油烃化合物(TPH)调查表明:上海城市绿地表层土壤虽有不同程度的TPH累积,但整体污染情况并不严重;在不同类型绿地中,以外环道路周边绿地的TPH含量最高,且离道路和土壤表层越近,TPH累积越明显;汽车尾气可能是城市绿地土壤TPH的主要污染源。绿地土壤TPH含量与土壤有机质、Cu、真菌含量之间相关性不显著;但与Zn、Cd、细菌、微生物总量存在极显著相关,与Pb、放线菌含量之间存在显著相关;在低浓度TPH含量下,其可能作为绿地土壤微生物生长所需的碳源和能源,刺激微生物量的增加。上海绿地土壤C6~C9段TPH均低于检出限,以高碳段TPH为主,毒性较小;但交通流量大且以燃烧柴油车为主的外环周边绿地不但TPH总量高且检出低碳段TPH,其TPH潜在污染和毒害应引起重视。     

Environmental Impact of using actinium (228Ac)-contaminated sludge as soil conditioner and sand substitute

Low-level actinium contamination (²²⁸Ac) of petroleum sludge is reported. The sludge is earmarked for road-building and soil enrichment, hence long-term radiation in low doses is not desirable. We subsequently investigated the distribution of this radioactivity over a one-year period. Collection was conducted at different sites, and the sludge was subjected to high-resolution gamma-ray measurement with a Geenlarge this page detector. Samples of 1 kg dry weight were prepared in suitable Marinelli beakers and counted for 12 h. The approximate literature guideline for this radioistope in soil and regular sludge is about 60 Bq/kg. The levels in many of our samples were several times higher, and activities up to 600 Bq/kg were observed. The general distribution was studied; and suggestions for possible preventative remediation to deplete the activity levels in the sludge prior to its use as a building material and on sludge-farms are outlined. The study, therefore, formed an interesting contribution to research associated with radioactivity in the environment.     

Use of a greenhouse as an open chamber for canopy gas exchange measurements: Methodology and validation

Measurements of whole-canopy gas exchange - of CO₂ and H₂O - are important for agricultural and ecological reasons. The objective of this study was to investigate the use of a full-size greenhouse as an open-chamber system for measuring canopy-scale gas exchange. Measurements were validated by comparison with gas exchange scaled up from leaf- and plant-level measurements. Leaf-level measurements used a conventional hand-held cuvette gas exchange system at many points in the greenhouse. The experiments were done in a greenhouse with an area of (15 × 24) m² in which a pepper crop was grown. Within the canopy photosynthetic activity and transpiration changed with height, as expected. In addition, it was shown both theoretically and experimentally that in the absence of air mixing within the chamber, gradients of CO₂ and H₂O developed along the airflow direction. Theoretical estimates of the gradients were in good agreement with measured values. In spite of the gradients, canopy photosynthesis and transpiration could be estimated relatively accurately. For instance, the values of canopy photosynthesis and transpiration, during the course of the day, as measured with the open-chamber approach, were in good agreement with mean values obtained from measurements on individual leaves. However, transpiration values obtained both from open-chamber measurements and from individual leaves were generally a little lower than those obtained with lysimeters.     

Ceramic Aggregate Sorption and Desorption Chemistry: Implications for Use as a Component of Soilless Media

Ceramic aggregates (Turface® and Profile®) are common soilless media components, but their sorption/desorption chemistry is poorly understood. We investigated: labile (readily desorb-able or readily plant-available) ion concentrations; the effect of rinsing and soaking pretreatments on labile ions; sorption of applied nutrients; and nutrient uptake from the aggregates by plants. Variability in labile ions was extremely high among bags of aggregates. Manganese, boron, magnesium, calcium, sulfur and potassium were most likely to desorb in excess for plants. Phosphorus, iron, copper and zinc were sorbed by the aggregates; only copper was found nearly deficient in plant tissue. Rinsing and soaking pretreatments adjusted labile ions to more suitable concentrations for plants. However, growth data suggested a worst-case scenario of high levels of labile ions may not be mitigated by these pretreatments. With frequent leaching after planting or where the aggregates are a minor component of media, excessive nutrient uptake would likely be limited.     

Quick screening of cowpea (Vigna unguiculata) genotypes for aluminium tolerance in an aluminium-treated acid soil

In greenhouse experiments with small pots, seeds of cowpea (Vigna unguiculata) were planted into an acid soil (Oxic Paleudult from Onne, South-East Nigeria) which had been treated with Al₂(SO₄)₃-Cowpea genotypes showed varying seedling growth inhibition within 7 days when grown in soil containing 2.2 meq Al/100 g soil. Soil and plant analysis confirmed, that Al toxicity, and consequently differences in Al tolerance, were responsible for the genotypically different seedling growth responses. 783 genotypes showed a wide range of Al tolerance when screened using this technique. In a long-term pot experiment the effect of Al application to the soil on seed yields of 9 genotypes was studied. Although no significant correlation could be found between depression by Al of seedling growth and grain yield of the genotypes, the same genotypes were classified as most tolerant and most sensitive in both cases. The results show that the simple and quick screening method using Al-treated soil allows the identification of genotypes adapted to soils with high Al supply.     

Homogentisic acid: a phenolic acid as a marker of strawberry-tree (Arbutus unedo) honey.

Analysis of organic acids in strawberry-tree (Arbutus unedo) honey showed the presence of an unknown acid as the main constituent. This compound was isolated and identified as homogentisic acid (2, 5-dihydroxyphenylacetic acid) by MS and NMR techniques. Its average content in honey was 378 +/- 92 mg/kg. Analysis of nectar confirmed the floral origin of the compound found in honey. Since this acid was not detected in any of the different monofloral honeys, it could be used as a marker of strawberry-tree (A. unedo) honey.     

The Interplay Between the Alfeios (Greece) River Basin Components and the Exerted Environmental Stresses: a Critical Review

The characteristics (natural, socioeconomic and administrative/institutional) of Alfeios River basin, in Greece, are identified and presented, incorporating and critically reviewing all possibly found literature. The Alfeios River is a water resources system of great natural, ecological, social and economic importance for Western Greece, since it has the longest and highest flow rate watercourse in the Peloponnisos region. Moreover, the river basin was exposed in the last decades to a plethora of environmental stresses (such as hydrogeological alterations, intensively irrigated agriculture, surface and groundwater overexploitation and infrastructure developments), resulting in the degradation of its quantitative and qualitative characteristics. It is therefore necessary for the development of an integrated river basin management plan for this basin, to study and analyse the interplay between the river components and the exerted environmental stresses, taking into account the puzzle of various and conflicting water uses, including water supply, irrigation, hydropower generation, lignite thermal power production and recreation. Mitigative, preventive and control measures for the analysed environmental stresses are epigrammatically depicted. Focusing on the problematic features, the present work provides a concrete foundation for the determination and conceptualisation of management objectives and possible sustainable alternatives.     

南湖水体多相介质中PAHs的分布特征及其来源分析

以南湖水体中的水、表层沉积物、生物膜和悬浮物为研究对象,对美国EPA规定的16种优控PAHs中13种PAHs的分布与富集特征进行了研究。结果表明,表层沉积物中检出12种PAHs,生物膜和水相中均检出11种PAHs,而悬浮物中只检出7种PAHs;生物膜和悬浮物富集PAHs的能力相近,比表层沉积物的富集能力大一个数量级;相关分析表明,生物膜和悬浮物富集PAHs的能力归因于其有机质（TOC）的含量高于表层沉积物中有机质的含量。根据菲/蒽比值和PAHs环数相对丰度对南湖表层沉积物中PAHs的来源进行了分析,发现南湖沉积物中的PAHs主要来自于化石燃料燃烧释放的污染。     

Evaluation of Compost Maturity,Hydrophysical and Physicochemical Properties: Indicators for Use as a Component of Growing Media

The cocomposting of agricultural waste is a new management priority in Tunisia. In this study, four composts were evaluated by comparing the changes in measured hydrophysical and physicochemical properties and phytotoxicity. The organic wastes used were almond shell (AS), sesame bark (SB), olive husk (OH), and green and wood wastes (GW and WW, respectively). Composts CI and CII were composed of AS/SB and OH/SB, respectively, at a ratio of 75/25 (wet weight basis). CIII consisted of OH, SB and CAS (coarsely-ground almond shell used as a bulking agent) at a ratio of 55/25/20. Finally, CIV was composed of 25%SB+9%CAS+18%GW+48%WW. The composts studied were characterized by basic pH and an electric conductivity (EC) value ranging from 1.6 to 2.4 mS/cm. The organic matter contents (OM) and C/N ratios of composts ranged from 20 to 46% and from 10 to 21%, respectively. Based on hydrophysical analyses, composts CI, CIII and CIV, containing AS, were shown to have a porosity and a water content of 10-26% and 10-20%, respectively. The phytotoxicity of composts was studied on the basis of cress seed germination. Results revealed that differences in properties are mainly related to the nature of composted waste and that some of these composts are compatible for use as constituents in growing media for horticultural soilless cultures.     

Sublittoral Chironomids as Indicators of Acidity (Diptera: Chironomidae)

The sublittoral chironomid fauna of 22 lakes in Killarney Park, Ontario, Canada were examined for their response to different levels of acidification. Included in the analysis were naturally acidic lakes, lakes acidified by atmospheric deposition but now recovering, and unacidified circumneutral lakes. pH in the study lakes ranged from 4.6 to 7.7. No correlation was found between species richness and pH, nor between abundance and pH. Acid neutralizing capacity (ANC), the temperature at the sampling depth, pH, and dissolved organic carbon were the variables contributing significantly in a canonical correspondence analysis of the abundance data. ANC was the most important variable in describing the chironomid community, accounting for about 9% of the variance in the species data. This study is the first step in an effort to model the changes in the chironomid community of recovering acidified lakes and the results suggest that ANC may be an important predictor variable.