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Результаты 1-10 из 13
Development of polyurethane-based passive samplers for ambient monitoring of urban-use insecticides in water
2017
Liao, Chunyang | Richards, Jaben | Taylor, Allison R. | Gan, Jay
Widespread use of insecticides for the control of urban pests such as ants, termites, and spiders has resulted in contamination and toxicity in urban aquatic ecosystems in different regions of the world. Passive samplers are a convenient and integrative tool for in situ monitoring of trace contaminants in surface water. However, the performance of a passive sampler depends closely on its affinity for the target analytes, making passive samplers highly specific to the types of contaminants being monitored. The goal of this study was to develop a passive sampler compatible with a wide range of insecticides, including the strongly hydrophobic pyrethroids and the weakly hydrophobic fipronil and organophosphates. Of six candidate polymeric thin films, polyurethane film (PU) was identified to be the best at enriching the test compounds. The inclusion of stable isotope labeled analogs as performance reference compounds (PRCs) further allowed the use of PU film for pyrethroids under non-equilibrium conditions. The PU sampler was tested in a large aquarium with circulatory water flow, and also deployed at multiple sites in surface streams in southern California. The concentrations of pesticides derived from the PU sampler ranged from 0.5 to 18.5 ng/L, which were generally lower than the total chemical concentration measured by grab samples, suggesting that suspended particles and dissolved organic matter in water rendered them less available. The influence of suspended particles and dissolved organic matter on bioavailability was more pronounced for pyrethroids than for fipronils. The results show that the developed PU film sampler, when coupled with PRCs, may be used for rapid and sensitive in-situ monitoring of a wide range of insecticides in surface water.
Показать больше [+] Меньше [-]Mercury flow through an Asian rice-based food web
2017
Abeysinghe, Kasun S. | Qiu, Guangle | Goodale, Eben | Anderson, Christopher W.N. | Bishop, Kevin | Evers, David C. | Goodale, Morgan W. | Hintelmann, Holger | Liu, Shengjie | Mammides, Christos | Quan, Rui-Chang | Wang, Jin | Wu, Pianpian | Xu, Xiao-Hang | Yang, Xiao-Dong | Feng, Xinbin
Mercury (Hg) is a globally-distributed pollutant, toxic to humans and animals. Emissions are particularly high in Asia, and the source of exposure for humans there may also be different from other regions, including rice as well as fish consumption, particularly in contaminated areas. Yet the threats Asian wildlife face in rice-based ecosystems are as yet unclear. We sought to understand how Hg flows through rice-based food webs in historic mining and non-mining regions of Guizhou, China. We measured total Hg (THg) and methylmercury (MeHg) in soil, rice, 38 animal species (27 for MeHg) spanning multiple trophic levels, and examined the relationship between stable isotopes and Hg concentrations. Our results confirm biomagnification of THg/MeHg, with a high trophic magnification slope. Invertivorous songbirds had concentrations of THg in their feathers that were 15x and 3x the concentration reported to significantly impair reproduction, at mining and non-mining sites, respectively. High concentrations in specialist rice consumers and in granivorous birds, the later as high as in piscivorous birds, suggest rice is a primary source of exposure. Spiders had the highest THg concentrations among invertebrates and may represent a vector through which Hg is passed to vertebrates, especially songbirds. Our findings suggest there could be significant population level health effects and consequent biodiversity loss in sensitive ecosystems, like agricultural wetlands, across Asia, and invertivorous songbirds would be good subjects for further studies investigating this possibility.
Показать больше [+] Меньше [-]Aquatic subsidies transport anthropogenic nitrogen to riparian spiders
2011
Akamatsu, Fumikazu | Toda, Hideshige
Stable nitrogen isotopic composition (δ¹⁵N) of aquatic biota increases with anthropogenic N inputs such as sewage and livestock waste downstream. Increase in δ¹⁵N of riparian spiders downstream may reflect the anthropogenic pollution exposure through predation on aquatic insects. A two-source mixing model based on stable carbon isotopic composition showed the greatest dependence on aquatic insects (84%) by horizontal web-building spiders, followed by intermediate (48%) and low (31%) dependence by cursorial and vertical web-building spiders, respectively. The spider body size was negatively correlated with the dietary proportion of aquatic insects and spider δ¹⁵N. The aquatic subsidies transported anthropogenic N to smaller riparian spiders downstream. This transport of anthropogenic N was regulated by spider’s guild designation and body size.
Показать больше [+] Меньше [-]Floodplain methylmercury biomagnification factor higher than that of the contiguous river (South River, Virginia USA)
2011
Newman, Michael C. | Xu, Xiaoyu | Condon, Anne | Liang, Lian
Mercury biomagnification on the South River floodplain (Virginia, USA) was modeled at two locations along a river reach previously modeled for methylmercury movement through the aquatic trophic web. This provided an opportunity to compare biomagnification in adjoining trophic webs. Like the aquatic modeling results, methylmercury-based models provided better prediction than those for total mercury. Total mercury Food Web Magnification Factors (FWMF, fold per trophic level) for the two locations were 4.9 and 9.5. Methylmercury FWMF for the floodplain locations were higher (9.3 and 25.1) than that of the adjacent river (4.6). Previous speculation was not resolved regarding whether the high mercury concentrations observed in floodplain birds was materially influenced by river prey consumption by riparian spiders and subsequent spider movement into the trophic web of the adjacent floodplains. Results were consistent with a gradual methylmercury concentration increase from contaminated floodplain soil, to arthropod prey, and finally, to avian predators.
Показать больше [+] Меньше [-]The effects of simulated acid rain on growth and susceptibility to predation of Phratora polaris (Col., Chrysomelidae)
1995
Palokangas, P. | Neuvonen, S. | Haapala, S. (Kevo Subarctic Research Institute, University of Turku, A777 Kevo, FIN-99800 Ivalo (Finland))
Walking behaviour and population density of adult linyphiid spiders in relation to minimizing the plot size in short term pesticide studies with pyrethroid insecticides
1993
Jagers op Akkerhuis, G.A.J.M. (Department of Toxicology, Wageningen Agricultural University, PO Box 8129, 6700 EV Wageningen (Netherlands))
Assessment of heavy metals in surface water, sediment and macrozoobenthos in inland rivers: a case study of the Heihe River, Northwest China
2022
Wang, Yu | Li, Bao-long | Zhu, Jia-le | Feng, Qi | Liu, Wei | He, Yu-hua | Wang, Xu
Long-term retention and accumulation of heavy metals in surface water and sediment pose a great threat to the sustainable development of aquatic ecosystems and human health. In this research, macrozoobenthos, and surface water and sediment heavy metal (Mn, Cr, Cu, Ni, Pb, Zn, Cd, and As) samples were collected from 23 sites in the upper and middle reaches of the Heihe River in the summers of 2019–2020. The interrelationships between heavy metals and macrozoobenthos were analyzed by Pearson correlation analysis and redundancy analysis (RDA), and the contamination level and potential ecological risk of the heavy metals in surface water and sediments were assessed by comprehensive pollution index (WQI), single potential ecological risk index ([Formula: see text]), and sediment quality guideline-quotient (SQG-Q), respectively. The results showed that the level of heavy metal pollution in the surface water of the Heihe River was extremely low, but the contents of Mn and Pb exceeded the third class of surface water environmental quality standards (GB 3838–2002). The spatial distribution of heavy metals in surface sediments were significantly different, and the average concentration of 8 heavy metals exceeded the background values of Gansu Province. Meanwhile, the pollution level of heavy metals in surface sediments was high pollution, and the ecological risk level was moderate risk. Combining [Formula: see text] and SQG-Q evaluations showed that Cd, Ni, and Cr were the main ecological risk factors. In addition, the distribution coefficients of Cr and Cd were low, indicating that Cr and Cd were easily released from the surface sediments, causing secondary pollution. In terms of the source of the heavy metals, Cu, As, Zn, Cr, and Ni mainly came from industrial and agricultural wastewaters, Pb was from the mining industry and natural sources, and Mn and Cd mainly came from tailings and their landfill leachate. Basommatophora and Araneae can be used as potential indicator organisms for heavy metal pollution in surface water, and Basommatophora, Coleoptera, Hemiptera, and Araneae can be used as indicator species for heavy metal pollution in surface sediments. The study showed that macroinvertebrate community characteristics had a sensitive response to heavy metals in the surface waters and sediments of the Heihe River, which can be used to evaluate the pollution status of heavy metals in inland rivers.
Показать больше [+] Меньше [-]Species Diversity and Community Structure of Ground-Dwelling Spiders in Unpolluted and Moderately Heavy Metal-Polluted Habitats
2008
Jung, Myung-Pyo | Kim, Sŭng-tʻae | Kim, Hunsung | Yi, Chun-ho
This study was conducted to investigate the relationship between ground-dwelling spider communities and the degree of soil contamination of heavy metals, Cd and Pb. Six sites were selected according to expected differences in Cd and Pb contamination levels in soil and similarity in vegetation composition. Ground-dwelling spiders were collected monthly in 2003 and 2004 by pitfall trapping. Species diversity of ground-dwelling spiders between unpolluted and moderately polluted sites was not significantly different although the value was higher in the unpolluted site. Species diversity tended to decrease with increasing Pb levels in soil although no statistical significance was obtained. No trend was shown between species diversity and Cd levels in soil. The community structure of ground-dwelling spiders was similar for the two types of sites. Overall ground-dwelling spider communities may be not sensitive enough to discriminate moderate heavy metal contamination levels in soil. However, among the dominant spider families, the composition and structure of Linyphiidae separated unpolluted and moderately polluted sites. Pardosa astrigera and P. laura (Lycosidae) have a potential as heavy metal accumulator indicator species and Oedothorax insulanus (Linyphiidae) has a potential as a heavy metal sentinel indicator species.
Показать больше [+] Меньше [-]Additional disturbances as a beneficial tool for restoration of post-mining sites: a multi-taxa approach
2016
Řehounková, Klára | Čížek, Lukáš | Řehounek, Jiří | Šebelíková, Lenka | Tropek, Robert | Lencová, Kamila | Bogusch, Petr | Marhoul, Pavel | Máca, Jan
Open interior sands represent a highly threatened habitat in Europe. In recent times, their associated organisms have often found secondary refuges outside their natural habitats, mainly in sand pits. We investigated the effects of different restoration approaches, i.e. spontaneous succession without additional disturbances, spontaneous succession with additional disturbances caused by recreational activities, and forestry reclamation, on the diversity and conservation values of spiders, beetles, flies, bees and wasps, orthopterans and vascular plants in a large sand pit in the Czech Republic, Central Europe. Out of 406 species recorded in total, 112 were classified as open sand specialists and 71 as threatened. The sites restored through spontaneous succession with additional disturbances hosted the largest proportion of open sand specialists and threatened species. The forestry reclamations, in contrast, hosted few such species. The sites with spontaneous succession without disturbances represent a transition between these two approaches. While restoration through spontaneous succession favours biodiversity in contrast to forestry reclamation, additional disturbances are necessary to maintain early successional habitats essential for threatened species and open sand specialists. Therefore, recreational activities seem to be an economically efficient restoration tool that will also benefit biodiversity in sand pits.
Показать больше [+] Меньше [-]A multidiversity approach to investigate the impact of mining exploitation on spider diversity in the abandoned mine district of Montevecchio-Ingurtosu (Sardinia, Italy)
2020
Mannu, Roberto | Pantini, Paolo | Sassu, Antonio | Verdinelli, Marcello
The impact of mining activities on spider (Araneae) diversity and assemblages was studied in two abandoned mine sites in Sardinia (Italy), where mining activities started in the middle of the nineteenth century and closed down over a century later. Spider community composition was analysed in dumps, undisturbed forests and scrublands which represent the natural chronosequence following the abandonment of the mining district. The identification of spiders was performed at the lowest taxonomic level possible and differences in abundance, species richness (SR), and functional diversity (FD) were analysed. Nonmetric multidimensional scaling (NMDS) and a permutated multivariate analysis of variance (PERMANOVA) routine were conducted to evaluate the relationships of spider assemblages with land cover, and the indicator species analysis was performed to identify the typifying species. During the entire sampling period, 2312 spiders were captured, and approximately 80% of the total were identified at the species level (79 spider species belonging to 28 different families). No differences in abundance and SR were found, whereas FD, which showed the highest values in forests, significantly differed among sites. A distinct separation among assemblages and a significant effect of the land use on spider assemblages were found (PERMANOVA, R² = 0.59, p < 0.001). Twelve species were selected as indicator species. Our results underlined the possibility to consider ground-dwelling spiders as a valuable target group for biomonitoring programmes supporting projects of near-natural restoration and/or technical reclamation of mining sites.
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