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81.
Evidence for the effects of metal contamination on the intertidal macrobenthic assemblages of the Fal Estuary 总被引:3,自引:0,他引:3
Warwick RM 《Marine pollution bulletin》2001,42(2):145-148
The intertidal invertebrate macrofauna of five creeks in the Fal estuarine system, Cornwall, UK, is compared with data from 40 locations in six other estuaries in south-west Britain. Multivariate analysis shows that the community composition in the Fal is distinct from all the other estuaries. The differences are principally due to the absence of two crustacean species, Corophium voluntator and Cyathura carinata, and the high abundance of small opportunistic annelid species. The Fal Estuary is heavily contaminated with heavy metals as a result of mining in the catchment, and the faunistic features are commensurate with what is known of the relative sensitivities of marine invertebrate taxa to pollution. 相似文献
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地质热事件—有机质—金属成矿作用的联系 总被引:7,自引:0,他引:7
地质热事件引起有机质发生种种变化,也导致金属矿床的形成。地质热事件的性质不同,有机质变化的特点及成矿作用的类型也不尽相同。地质热事件与有机质的变化、金属成矿作用在发生时间、共生空间和形成原因诸方面均存在着密切的联系。 相似文献
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Khraif RM 《GeoJournal》1992,26(3):363-370
"The aim of this paper is to investigate the factors affecting intentions of rural-migrants to return to their rural origins. Several socioeconomic, demographic, spatial, and temporal variables will be introduced to explore their explanatory power and interrelationship with the migrants' intentions. These variables are: Years lived in Riyadh, the current place of parents' residency, land ownership in the village, home ownership in the urban area, income, household size, and the area of origin. The data, which come from a sample survey of migrants conducted in Riyadh in 1983, will be analyzed by the means of binary logit model." 相似文献
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Although the degree of metal contamination is expected to be a primary determinant of metallothionein (MT) induction in marine mussels, at least at polluted sites, variability caused by temperature, and biotic factors such as size, may need to be considered when interpreting field data. To test the effects of these variables, mussels, Mytilus galloprovincialis, of different sizes (small: 3.5 +/- 0.5 cm and large: 5.2 +/- 0.7 cm) were exposed to Cd (100 microg l(-1)) at different water temperatures (5, 18 and 25 degrees C) for 34 days. Resultant Cd and MT concentrations in gills were shown to be size dependent and increased significantly with temperature. At the highest temperature tested (25 degrees C) there appears to be a disproportionate effect on Cd accumulation, which raises MT synthesis to exceptionally high levels. The effect of size on MT concentrations was also temperature-dependent: at 18 and 25 degrees C, large mussels exhibited higher MT levels than smaller individuals, whilst at 5 degrees C there were no significant differences between contaminated and control mussels, in either size-group, as a result of the reduced level of MT production at this temperature. When considering the use of MT levels in mussels as a biochemical indicator of metal contamination, the potential influence of factors such as size and temperature on MT-metal relationships needs to be considered. Samples should be of uniform size as far as possible, and collection should be limited to a fixed season (avoiding climatic extremes) to ensure that the effects of these factors on baseline levels of MT is minimised. 相似文献
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