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31.
Vinogradoff SI Graham MC Thornton GJ Dunn SM Bacon JR Farmer JG 《Journal of environmental monitoring : JEM》2005,7(5):431-444
As a consequence of the accumulation of anthropogenic Pb in upland catchments, there has been much recent concern about the potential mobilisation and transport of Pb from the soils to receiving waters and also the possible harmful effects that this might have on aquatic biota. This paper presents the findings of a two-year study of Pb behaviour in an organic-rich upland catchment at Glensaugh in NE Scotland. Pb inputs to the catchment were characterised by direct measurements of Pb concentration and (206)Pb/(207)Pb ratios in rain water and interception. Pb outputs from the catchment were calculated from measurements on stream water samples taken from the two main streams, the Cairn Burn and Birnie Burn. The relative contribution of Pb from groundwater and throughflow, under different flow conditions (base flow and high flow), to stream waters was investigated via analysis of springs sourced from groundwater and of waters flowing through the various soil horizons (S (surface), A, B, C, and D), respectively. The outcome of intensive sampling and analysis over the two-year time period was that, even with marked reduction in Pb inputs over the past two decades, the catchment was still acting as a net sink for the current atmospheric deposition. Although the Pb isotopic signature for stream water is very similar to that for the contemporaneous rain water ((206)Pb/(207)Pb approximately 1.15-1.16), only a small portion of the rain water is transferred directly to stream water. Instead, the Pb input is transferred to the stream waters mainly via groundwater and it was also confirmed that the latter had a similar Pb isotopic signature. From the Pb isotopic measurements on throughflow waters, however, Pb being removed via the streams contained some previously deposited Pb, i.e. mobilisation of a small portion of soil-derived anthropogenic Pb was occurring. These findings are important not only with respect to the source/sink status of the catchment but also for calculation of the extent of retention of the current atmospheric Pb inputs, which must take account of the release of previously deposited Pb from the catchment soils, a process occurring mainly under high flow conditions. 相似文献
32.
L. J. Wilson P. J. Bacon J. Bull U. Dragosits A. G. Mcdonald T. D. Blackall T. E. Dunn K. C. Hamer M. A. Sutton S. Wanless 《Water, Air, & Soil Pollution: Focus》2005,4(6):287-296
Simple bioenergetics models were used to derive annual nitrogen excretion rates of each seabird species occurring at colonies in the UK. These were combined with population distribution data and an estimated fraction of nitrogen volatilized to estimate the spatial distribution of NH3 emissions from seabird colonies at a 1 km resolution. The effect of these emissions on atmospheric NH3 concentrations and nitrogen deposition in the UK was assessed using the FRAME atmospheric chemistry and transport model. The total emission of NH3 from the UK seabird colonies is estimated at 2.7 kt yr?1. Emissions from seabirds are largely concentrated in remote parts of Britain, where agricultural and other anthropogenic emissions are minimal. Although seabirds account for less than 1% of total UK NH3 emissions (~370 kt yr?1), their occurrence in remote areas and frequently large colony sizes results in seabirds providing a major fraction of the atmospheric nitrogen deposition for many remote ecosystems. 相似文献
33.
The marine environment is being increasingly exploited by fisheries and the oil and gas industry. Conservationists urgently
need the ability to identify the processes that determine patterns of abundance of marine species. We describe a preliminary
Geographic Information System (GIS) in which spatial data on environmental variables (seabird colony locations, sea depth
and seabed sediments) are integrated with realistic energy constraints faced by marine birds during the breeding season. A
simple foraging model predicts the spatial variation in the quality of given locations as potential feeding sites under different
feeding conditions and stages of the breeding cycle. We show how the approach can be used to help managers identify key marine
areas and assess the impacts of environmental change or damage. 相似文献
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35.
The potential environmental impacts from the use of treated timber in aquatic areas is under scrutiny as a result of environmental legislation and reports of the deleterious environmental effects around treated structures. In this study leaching experiments of up to 3 weeks duration were conducted on two species of chromated copper arsenate treated timber, dried for different periods of time. Increased drying time significantly reduced leaching of Cr and As. The addition of a synthetic humic acid increased leaching of Cu and As, but reduced leaching of Cr. Putative risk assessments conducted using short-term copper leaching data suggested protocol design may influence decisions made regarding the environmental acceptability of such preservatives. 相似文献
36.
L. J. Wilson P. J. Bacon J. Bull U. Dragosits A. G. Mcdonald T. D. Blackall T. E. Dunn K. C. Hamer M. A. Sutton S. Wanless 《Water, Air, & Soil Pollution: Focus》2004,4(6):287-296
Simple bioenergetics models were used to derive annual nitrogen excretion rates of each seabird species occurring at colonies in the UK. These were combined with population distribution data and an estimated fraction of nitrogen volatilized to estimate the spatial distribution of NH3 emissions from seabird colonies at a 1 km resolution. The effect of these emissions on atmospheric NH3 concentrations and nitrogen deposition in the UK was assessed using the FRAME atmospheric chemistry and transport model. The total emission of NH3 from the UK seabird colonies is estimated at 2.7 kt yr–1. Emissions from seabirds are largely concentrated in remote parts of Britain, where agricultural and other anthropogenic emissions are minimal. Although seabirds account for less than 1% of total UK NH3 emissions (370 kt yr–1), their occurrence in remote areas and frequently large colony sizes results in seabirds providing a major fraction of the atmospheric nitrogen deposition for many remote ecosystems. 相似文献