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551.
Burger J Gochfeld M Jeitner C Burke S Volz CD Snigaroff R Snigaroff D Shukla T Shukla S 《Environmental monitoring and assessment》2009,152(1-4):179-194
Levels of mercury and other contaminants should be lower in birds nesting on isolated oceanic islands and at high latitudes without any local or regional sources of contamination, compared to more urban and industrialized temperate regions. We examined concentrations of arsenic, cadmium, chromium, lead, manganese, mercury and selenium in the eggs, and the feathers of fledgling and adult glaucous-winged gulls (Larus glaucescens) nesting in breeding colonies on Adak, Amchitka, and Kiska Islands in the Aleutian Chain of Alaska in the Bering Sea/North Pacific. We tested the following null hypotheses: 1) There were no differences in metal levels among eggs and feathers of adult and fledgling glaucous-winged gulls, 2) There were no differences in metal levels among gulls nesting near the three underground nuclear test sites (Long Shot 1965, Milrow 1969, Cannikin 1971) on Amchitka, 3) There were no differences in metal levels among the three islands, and 4) There were no gender-related differences in metal levels. All four null hypotheses were rejected at the 0.05 level, although there were few differences among the three test sites on Amchitka. Eggs had the lowest levels of cadmium, lead, and mercury, and the feathers of adults had the lowest levels of selenium. Comparing only adults and fledglings, adults had higher levels of cadmium, chromium, lead and mercury, and fledglings had higher levels of arsenic, manganese and selenium. There were few consistent interisland differences, although levels were generally lower for eggs and feathers from gulls on Amchitka compared to the other islands. Arsenic was higher in both adult feathers and eggs from Amchitka compared to Adak, and chromium and lead were higher in adult feathers and eggs from Adak compared to Amchitka. Mercury and arsenic, and chromium and manganese levels were significantly correlated in the feathers of both adult and fledgling gulls. The feathers of males had significantly higher levels of chromium and manganese than did females. The levels of most metals in feathers are below those known to be associated with adverse effects in the gulls or their predators. However, levels of mercury in some gull eggs are within a range suggesting that several eggs should not be eaten in one day by sensitive humans. 相似文献
552.
Isabelle J. Brisson Patrick Levallois Hélène Tremblay Jean Sérodes Christian Deblois Jeffrey Charrois Vincent Taguchi Jessica Boyd XingFang Li Manuel J. Rodriguez 《Environmental monitoring and assessment》2013,185(9):7693-7708
The spatiotemporal presence of eight N-nitrosamines in the water of seven supply systems in Quebec considered to be susceptible to these emerging disinfection by-products was evaluated. This is the first study on the presence of N-nitrosamines in drinking water utilities in Quebec. Seven sampling campaigns were carried out at several sampling points in each of the systems over a period of 1 year. The results show that N-nitrosamines, primarily N-nitrosodimethylamine (NDMA), were not commonly detected in the water of the facilities under study (10 % of samples). The concentrations measured were lower than those reported in recent North American studies. None of the 195 samples taken exceeded the Ontario standard of 9 ng/L for NDMA (maximum value observed of 3.3 ng/L). N-nitrosomethylethylamine and N-nitrosopiperidine were detected once, with concentrations of 3.7 and 6.0 ng/L, respectively. Chloramination was identified as being the main risk factor regarding the presence of N-nitrosamines, but water quality and some operating parameters, in particular disinfectant residual, also seem to be related to their presence. NDMA concentrations at the end of the distribution systems were generally higher than water leaving the plant. No seasonal trends were observed for the formation of N-nitrosamines in the investigated supply systems. Finally, an association between the presence of N-nitrosamines and the levels of trihalomethanes and haloacetic acids was observed in some facilities. 相似文献
553.
This study aimed to optimise the methodology for the use of Corophium insidiosum in a bioassay. Taking into account that it would be suitable to execute the bioassay with organisms having a good sensitivity
during the year and low mortality in control sediment, the influence of different temperatures (10–15–20 and 25°C) has been
examined. C. insidiosum was collected during August, November 2005 and January 2006, in Mar Piccolo basin (Ionian sea). The results obtained show
that this species mortality in the negative control sediment, ranged from 2.6 ± 0.6% at 10°C in August to 17 ± 2.2% at 20°C
in November, at different temperatures tested. At 20°C there were significant differences in mortality among different months
examined. Indeed no relationship among months was found at 15°C. Significant differences between August and November at 25°C,
between November and January were not found at 10°C. The 96-h LC50 values found for cadmium at all temperature experimental
conditions ranged from 2.11 mg/l (1.57–2.82) to 0.70 mg/l (0.54–0.93). The highest values were found at 10°C in November and
January. The results showed that the optimal temperature for the bioassay seems to be between 15°C and 20°C. Even if, at 20°C
the mortality differs significantly among organisms sampled. 相似文献
554.
Barbara A. Caspers Frank C. Schroeder Stephan Franke W. Jürgen Streich Christian C. Voigt 《Behavioral ecology and sociobiology》2009,63(5):741-749
Combining chemical analysis and odour preference tests, we asked whether two closely related sympatric species of sac-winged
bats use odour for species recognition. Males of the two sister species Saccopteryx bilineata and Saccopteryx leptura have pouches containing an odoriferous liquid in their antebrachial wing membrane, which is used in S. bilineata during courtship displays. Although both species occasionally share the same daytime roosts and are morphologically similar,
there is no evidence for interbreeding. We compared the production and composition of the wing sac odorant in male S. leptura and S. bilineata and performed odour preference tests with female S. bilineata. Similar to male S. bilineata, male S. leptura cleansed and refilled their wing sacs with secretions, but they spent more time each day in doing so than male S. bilineata. Chemical analysis by gas chromatography and mass spectrometry revealed that male Saccopteryx carried species-specific scents in their wing sacs. Binary choice tests confirmed that female S. bilineata preferred the wing sac scents of male S. bilineata to those of the sister species, suggesting that the species specificity of male wing sac scents maintain the pre-mating isolation
barrier between these closely related species. 相似文献
555.
Ecological network analyses and their use for establishing reference domain in functional assessment of an estuary 总被引:1,自引:0,他引:1
Robert R. Christian Mark M. Brinson James K. Dame Galen Johnson Charles H. Peterson Daniel Baird 《Ecological modelling》2009,220(22):3113
We developed a framework to use ecological network analysis for functional assessment of large aquatic ecosystems in the context of ecosystem-based management. We established a reference domain for the Neuse River Estuary, North Carolina, USA, from changes over time. Four reference network models of the trophic structure of the estuary during early and late summers of 1997 and 1998 were constructed and analyzed. The estuary has experienced various symptoms of eutrophication during the past 20 years, including summer-time hypoxia and fish kills. The networks were used to quantify indices of nominal trophic dynamics and their variation. The ratio of biomass of nekton to that of macrobenthos, derived from network construction, was used to index severity of eutrophication and to promote accessibility of ecological network analysis to environmental management. The ratio increased from early to late summer, and network metrics demonstrated a variety of responses in association with that change. Some variables from network analysis, especially related to consumers, reflected some but not all of this change. Others reflected the most severe increase in the ratio in late summer 1997 when hypoxia was most extensive. We evaluated uncertainty and the modulating effects of hierarchy by comparing variation of input biomasses with integrative response variables. Relative variation in input variables was generally greater than that of the integrative response variables as predicted by hierarchy theory. Ecological network analysis has previously served as support for ecosystem-based management of large aquatic systems with some success. However, its use can be enhanced by making it more accessible to environmental managers and policy makers. Ways to do this include promoting simple metrics from network construction and explicitly associating network analysis to concepts familiar to the management community, such as functional assessment and reference. 相似文献
556.
Volker Huckstorf Wolf-Christian Lewin Thomas Mehner Christian Wolter 《Behavioral ecology and sociobiology》2009,63(12):1735-1742
Animal prey has developed a variety of behavioural strategies to avoid predation. Many fish species form shoals in the open
water or seek refuge in structurally complex habitats. Since anti-predator strategies bear costs and are energy-demanding,
we hypothesised that the nutritional state of prey should modify the performance level and efficiency of such strategies.
In aquaria either containing or lacking a structured refuge habitat, well-fed or food-deprived juvenile roach (Rutilus rutilus) were exposed to an open-water predator (pikeperch, Sander lucioperca). Controls were run without predators. In the presence of the predator, roach enhanced the performance of the anti-predator
strategy and increased the use of the refuge habitat whereby food-deprived roach were encountered more often in the structure
than well-fed roach. Nonetheless more starved than well-fed roach were fed upon by the predator. In the treatments offering
only open-water areas, roach always formed dense shoals in the presence of the predator. The shoal density, however, was lower
in starved roach. Starving fish in shoals experienced the highest predation mortality across all experimental treatments.
The experiment confirmed the plasticity of the anti-predator behaviour in roach and demonstrated that food deprivation diminished
the efficiency of shoaling more strongly than the efficiency of hiding. The findings may be relevant to spatial distribution
of prey and predator–prey interactions under natural conditions because when prey are confronted with phases of reduced resource
availability, flexible anti-predator strategies may lead to dynamic habitat use patterns. 相似文献
557.
Jann Peyrat Małgorzata Braun Christian Dolnik Maike Isermann Hartmut Roweck 《Journal of Coastal Conservation》2009,13(4):235-246
Coastal dune ecosystems are among the most dynamic habitats with high conservation value in Europe but are also under strong
anthropogenic pressure regarding coastal protection and recreation. Hence, it is of high importance to know about long-term
natural and anthropogenic changes and development of protected dune habitats for nature conservation, as well as for coastal
management. This paper aims to identify the vegetation dynamics on the Łeba Bar/Poland over a period of 74 years by cartometric
comparison using modern Geographical Information System (GIS). To quantify the rate of vegetation dynamics two aerial photographs
dating from 1932 and 2006 were digitalized and analyzed with GIS to produce digital vegetation maps. Information about decrease,
increase and stability of vegetation types of this area are discussed. The results show that there has been a clear reduction
in the total area of bare sand and a considerable increase of woodlands and dense grass communities. Nevertheless, the remaining
extensive drift sand areas and deflation hollows on the Łeba Bar offer one of the most important habitats for pioneer vegetation
on bare sand of migrating dunes and dunes at the Southern Baltic coast. The present work proved the need to observe the future
development of the vegetation communities and to implement management measures to maintain the dynamic of this unique dune
landscape. 相似文献
558.
Chemically chlorinated organic matter as well as natural background humic acids contain significant amounts of organically bound halogens that must be determined for assessment of environmental pollution. In this work the use of ion chromatography (IC) and inductively coupled plasma mass spectrometry (ICP-MS) is proposed for the determination of total organic Cl, Br and I concentration in humic acids extracted from various forest soil horizons after a single digestion by microwave-induced combustion (MIC). Samples were pressed as pellets and combusted using 20 bar of oxygen and ammonium nitrate solution as igniter. Analytes were absorbed in diluted alkaline solution (50 mM (NH4)2CO3) and a reflux step was applied after combustion to improve analyte recoveries (5 min, microwave power of 1400 W). The accuracy was evaluated using certified reference materials (CRM) and spiked samples. Using MIC the agreement with CRM values and spike recoveries was higher than 97% for all analytes. As an advantage over conventional procedures, using MIC it was possible to digest up to eight samples in only 25 min, obtaining a single solution suitable for all halogens determination in humic acids samples by different techniques (IC and ICP-MS). The limit of detection (3σ) for Cl, Br and I obtained by IC was 1.2, 2.5 and 4.3 μg g−1 and by ICP-MS it was 1.4, 0.03 and 0.002 μg g−1, respectively. 相似文献
559.
Aschberger K Micheletti C Sokull-Klüttgen B Christensen FM 《Environment international》2011,37(6):1143-1156
Production volumes and the use of engineered nanomaterials in many innovative products are continuously increasing, however little is known about their potential risk for the environment and human health. We have reviewed publicly available hazard and exposure data for both, the environment and human health and attempted to carry out a basic risk assessment appraisal for four types of nanomaterials: fullerenes, carbon nanotubes, metals, and metal oxides (ENRHES project 2009(1)). This paper presents a summary of the results of the basic environmental and human health risk assessments of these case studies, highlighting the cross cutting issues and conclusions about fate and behaviour, exposure, hazard and methodological considerations. The risk assessment methodology being the basis for our case studies was that of a regulatory risk assessment under REACH (ECHA, 2008(2)), with modifications to adapt to the limited available data. If possible, environmental no-effect concentrations and human no-effect levels were established from relevant studies by applying assessment factors in line with the REACH guidance and compared to available exposure data to discuss possible risks. When the data did not allow a quantitative assessment, the risk was assessed qualitatively, e.g. for the environment by evaluating the information in the literature to describe the potential to enter the environment and to reach the potential ecological targets. Results indicate that the main risk for the environment is expected from metals and metal oxides, especially for algae and Daphnia, due to exposure to both, particles and ions. The main risks for human health may arise from chronic occupational inhalation exposure, especially during the activities of high particle release and uncontrolled exposure. The information on consumer and environmental exposure of humans is too scarce to attempt a quantitative risk characterisation. It is recognised that the currently available database for both, hazard and exposure is limited and there are high uncertainties in any conclusion on a possible risk. The results should therefore not be used for any regulatory decision making. Likewise, it is recognised that the REACH guidance was developed without considering the specific behaviour and the mode of action of nanomaterials and further work in the generation of data but also in the development of methodologies is required. 相似文献
560.
Eulaers I Covaci A Herzke D Eens M Sonne C Moum T Schnug L Hanssen SA Johnsen TV Bustnes JO Jaspers VL 《Environment international》2011,37(3):622-630
In previous studies, feathers of adult predatory birds have been evaluated as valid non-destructive biomonitor matrices for persistent organic pollutants (POPs). In this study, we assessed for the first time the usefulness of nestling raptor feathers for non-destructive biomonitoring of POPs. For this purpose, we collected body feathers and blood of nestlings from three avian top predators from northern Norway: northern goshawks (Accipiter gentilis), white-tailed eagles (Haliaeetus albicilla) and golden eagles (Aquila chrysaetos). We were able to detect a broad spectrum of legacy POPs in the nestling feathers of all three species (Σ PCBs: 6.78-140ng g(-1); DDE: 3.15-145ng g(-1); Σ PBDEs: 0.538-7.56ng g(-1)). However, these concentrations were lower compared to other studies on raptor species, probably due to the aspect of monitoring of nestlings instead of adults. Besides their analytical suitability, nestling feathers also appear to be biologically informative: concentrations of most POPs in nestling feathers showed strong and significant correlations with blood plasma concentrations in all species (p<0.050; 0.775相似文献