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1.
Given the strategic situation of the José León de Carranza bridge, which spans the Bay of Cádiz (in the SW of Spain) and carries very heavy motor traffic, together with knowledge of the currents and tidal flows in the zone, we have used a technique of radioactive dating of sediments to study the temporal evolution presented by contamination from lead in the sediment column. This has allowed us to observe the environmental impact, in terms of the concentration of Pb in the sea bed sediments, that has been produced in the zone by the introduction of unleaded gasolines as substitutes for traditional automobile fuels that employ organic forms of tetra methyl lead as an antidetonant agent in the fuel.  相似文献   

2.
The third session of the Conference of the Parties to the UNFCCC was held in Kyoto, Japan, on 11 December 1997.  相似文献   

3.
Russian Journal of Ecology - This study has been carried out to determine water quality of Sang? Stream (West Anatolia, Turkey) and to compare the performance of indices used. Five biotic and...  相似文献   

4.
A hypothesis is considered that the establishment and maintenance of mass exchange processes in the Paramecium bursariasymbiotic complex (infusorian–alga) depends on the presence of the third component—bacteria—whose role is underestimated but essential for completing the exchange cycle. The role of this component in the symbiotic cycle of Paramecium bursariais possible to reveal using special bactericidal preparations specifically inhibiting the bacteria involved in the metabolic cycle but having no effect on the functions of the host cell and the zoochlorella population. Experiments with various preparations of this type were performed, and the response to treatment was estimated from growth rates of the symbiotic complex and its components. This allowed identification of an antibiotic (rifampicin) that had no adverse influence on free-living zoochlorella and chlorella-free paramecia (the basic components of the symbiotic cycle) but drastically inhibited the growth of the P. bursariasymbiotic complex, which could be interpreted as evidence in favor of the hypothesis concerning the existence of the third symbiotic component.  相似文献   

5.
Metallothioneins (MTs), malonedialdehyde (MDA), and glycogen concentrations were determined in order to assess the health status of Ruditapes decussatus exposed to in situ contamination, showing the effects of time, site, and metal contamination on these three biomarkers.Metallothionein was positively correlated with Cd and Zn. If introduced in a multiple model, the factors site and time were shown to decrease significantly MT concentrations. MDA was inversely correlated with size of the animals and was affected by the factor time. Glycogen was inversely correlated with zinc and was affected by both site and time.This study constitutes a field-based validation of a multiparametric approach using specific and nonspecific biomarkers.  相似文献   

6.
The significance of colloidal fractions regarding the transport of artificial radionuclides in natural water systems is underlined by using sequential ultrafiltration both in the Rh?ne freshwater and the marine area under and outside the influence of the river outflow. Indeed, the Rhodanian aquatic system represents an interesting test site as various artificial radionuclides are released into the Rh?ne river by several nuclear installations. We focused our study on (137)Cs, (106)Ru, (60)Co, (238)Pu and (239+240)Pu. Our results show that Fe, Al and Organic carbon (OC) are the main components of colloidal matter. Colloids represent about 15% of dissolved (<450 nm) OC and 25% of dissolved Fe and Al exported towards the sea. Within the dissolved (< 450 nm) phase, these colloidal compounds are shown to account for the transport of 40% for both Co and Ru, 60% for (238)Pu and (239+240)Pu and have no significance on (137)Cs flux.  相似文献   

7.
The United Nations Decadeof Education for SustainableDevelopment (DESD) was officially launched atUN Headquarters in New York on the afternoonof 1st March 2005, by UNESCO's DirectorGeneral Ko chiro Matsuura. The UN Decade ofEducation for Sustainable Development (2005-2014) aims to see Education for SustainableDevelopment implemented in thousands of localsituations on the ground, involving the integrationof the principles of Sustainable Development intoa multitude of different lea…  相似文献   

8.
Parc Natural sAlbufera de Mallorca is an internationally recognised resting area for a wide array of migratory birds, and like most wetlands it has many other ecological functions and socio-economic values. In the catchment, in which the wetland is situated, expanding tourism and intensification of agriculture place much pressure on a limited amount of freshwater. The freshwater supply to the wetland decreased due to water-extraction mainly driven by intensification of agriculture in the catchment. As a result saltwater intrusion increased since 1983–1985. This had considerable impacts on the ecological integrity of the wetland as reflected by changes in the state of the aquatic ecosystem. The distribution of submerged plants, less tolerant of salinity, declined or disappeared, while the distribution of species, known to prefer high salinity increased. As a contribution to the development of monitoring programs and management strategies that address both socio-economic and natural water demand, this article will formulate ecological criteria to assess the natural water demand by selection of (bio)indicators within the aquatic ecosystem.  相似文献   

9.
The fishing and hunting performed by inhabitants of the Extractive Reserve of the Upper Juruá, Acre, Brazil was studied, and an ecological analysis on the use of fish and game, including preferences, taboos and medicinal uses, and of fish abundance was made. Research was carried out at the Upper Juruá Extractive Reserve in three visits (1993 and 1994). A total of 143 individuals (101 families) living along the banks of the rivers Juruá, Tejo, Bagé, S. João and Breu were interviewed, and 115 species of fish with set gillnets were collected. Local economic activities included rubber-tapping and small-scale agriculture. Fishing was especially important in the dry season, when cast net and hook and line were used. Hunting and game consumption were intensive in the wet season. Some local rules may be useful as starting points for local management, such as the use of fish diversity through lake management, the use of water level seasonality, hunting periods or quotas, and food taboos. The integration of academic research with indigenous knowledge and demands is important to develop management plans which protect both biological and cultural diversity.  相似文献   

10.
The effect of long-term exposure to a stress factor on the pattern of variation and intrapopulation differentiation with respect to phenotypic plasticity was studied in Crepis tectorum L. by means of family analysis of various traits in seedlings. Trends in the changes of variation patterns in populations and the possible consequences of the decrease in the proportions of genotypes determining a low sensitivity to environmental changes and in genotypic diversity with respect to phenotypic plasticity are discussed.  相似文献   

11.
This article examines the Sarawak Corridor of Renewable Energy in Malaysia, or SCORE, a US $105 billion infrastructure development plan in Sarawak on the island of Borneo, from a sustainability standpoint. SCORE aims to build 20,000 megawatts of hydroelectric dams along a 320 km corridor comprising more than 70,000 km2 by 2030. The article begins by explaining social science methods utilized for its research interviews and site visits. It then argues that sustainability consists of seven principles articulated in international law: prudence, equity, responsibility, precaution, justice, governance, and compatibility. Next, the paper introduces readers to SCORE before assessing it according to these seven sustainability criteria. The paper finds that SCORE erodes environmental prudence by emitting millions of tons of carbon dioxide and feeding industries that will pollute the land and water. It worsens intergenerational equity by exacerbating poverty and consolidating wealth for corporations and politicians. It degrades responsibility by intensifying tropical deforestation and flaunts precaution by downplaying and ignoring risks to water quality and availability. It is unjust, imposing dams on communities and forcibly relocating thousands of indigenous people, mitigates good governance by condoning bribes and kickbacks along with the violent suppression of dissent, and is incompatible with Malaysia’s own energy policy targets and international standards.  相似文献   

12.
Spring water in the city of Jinan comes from the limestone areas. Understanding the capacity of wellspring conservation is a critical point to resume the perennial spewing of the spring water. The vegetation, soil, and other natural and human aspects related to the conservation are studied by using the methods of geographic information systems (GIS), remote sensing (RS), and field investigation. In the end, suggestions for administration and planning as well as countermeasures are put forward.  相似文献   

13.
Snow cover in Spanish mountains is crucial for ensuring water availability in spring and summer months, for the success of winter tourism or for the maintenance of biodiversity in mountain ecosystems. A changing climate may affect the volume of snow cover even in high mountains, where weather conditions are usually favorable for snow accumulation. In this paper, we aim to investigate the evolution (1970–2007) of combined precipitation–temperature modes in the Spanish mountains, and the sensitivity of the snowpack to their occurrence. The climatic database “Spain02” and snow thickness data for Spanish mountains were used for this purpose. Results showed that the frequency of dry-warm and wet-warm days has increased over time in all mountain ranges, while the frequency of the “cold” modes has decreased. The thickness of the snowpack in the Pyrenees has also decreased and its evolution is negatively correlated with the frequency of dry-warm days, and positively correlated with the frequency of dry-cold and wet-cold days. This work constitutes the first approach that relates the evolution of climatic conditions favorable or unfavorable for snow accumulation and the evolution of the snowpack in Spanish mountains.  相似文献   

14.
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15.
Minor and trace elements in the shell of Patella aspera (Röding 1798)   总被引:1,自引:0,他引:1  
Specimens of the limpet Patella aspera were collected from a clean, coastal marine site and a contaminated estuary on the south coast of Portugal. The shells were analysed individually for their minor (Mg, Sr) and trace element (Fe, Mn, Zn) content. Mean concentrations of these elements in the shell of P. aspera were 4651, 1318, 35.8, 29.9 and 5.5 microg g(-1), respectively. The elemental concentrations exhibited both a marked intra- and inter-population variability. Despite the variability within individual populations, significant differences in the trace element composition were apparent between the shells taken from the two sites. Small shells (< 2 g) provided the best resolution between sites for both manganese and iron. Differences in zinc were best resolved for larger shells. The shell of P. aspera has an extraordinarily high magnesium concentration, which is insensitive to gross salinity differences, and a trace metal assemblage that can be interpreted in terms of environmental exposure. On these grounds, it is recommended that the shell of P. aspera is a tissue for potential use in environmental trace metal monitoring.  相似文献   

16.
Within an extensive multinational and multidisciplinary project carried out in Do?ana National Park (Spain) to investigate its preservation and regeneration, the filling velocity of the salt marshes has been evaluated through the calculation of their average sediment accumulation rates. (239+240)Pu and (137)Cs from weapons testing fallout and total (210)Pb distribution profiles and inventories have been determined in some of the most characteristic zones of the park, namely, the ponds (or "lucios") and the waterjets (or "ca?os"). Plutonium inventories range from 16 to 101 Bq m(-2), (137)Cs values fluctuate between 514 and 3,758 Bq m(-2) and unsupported (210)Pb values comprise between 124 and 9398 Bq m(-2). Average sedimentation rates range from 3 to 5 mm y(-1) (1952-2002). These data are higher than those obtained by carbon dating for the period 6,500 AD-present, estimated as 1.5-2 mm y(-1), suggesting an increase in the accumulation of sediments and the alteration of the park's hydrodynamics caused by the re-channeling of the major rivers feeding the salt marshes.  相似文献   

17.
Nowadays, the disparity of the basic pension in local regions of China can be described as follows: the low level of the unification of the basic pension systems, the large disparity of the level of the basic pension, and unfairness of the enterprises’ payment for the basic pension in different local regions in China. These have already brought many negative influences, which have greatly held back the development of the society and national economy. We should build the basic pension system in all local regions of China as a whole, which can cover all people and decrease the disparity in different local regions in China.  相似文献   

18.
Relying on remote sensor technology, GIS and Land-sat TM digital images, the authors use spatial and statistical analysis to examine the temporal-spatial characteristics of the change caused by urban Construction in Xinjiang's rural areas from the end of the 1980s to the end of the 1990s. The primary findings show the following: 1) The urban construction in rural areas has increased drastically. The expansion speed of urban land use has accelerated over the past decade. The sub-land use changes caused by the urbanization of rural are characterized by salient regional differentiation among the three main regions and among the 85 counties of Xinjiang. 2) The shift of land use is mostly characterized by cultivated land and grassland being used for urban and industrial projects. Moreover, this change of land use is characteristic of regional differences. 3) Factors of rural-urban construction land use changes in Xinjiang, are undoubtedly affected by natural environment, social, economic conditions, and to a larger degree by population growth, GDP development and industrial development.  相似文献   

19.
Legacy organochlorine contaminants were determined in adipose tissues from 294 polar bears (Ursus maritimus) sampled in East Greenland in 23 of the 28 years between 1983 and 2010. Of 19 major legacy contaminants and congeners (ΣPCB, 4 PCB congeners (CB153, 180, 170/190), ΣDDT, p,p′-DDE, p,p′ -DDD and p,p′-DDT, α- and β-hexachlorocyclohexane (HCH), HCB, octachlorostyrene, dieldrin, oxychlordane, cis- and trans-chlordane, cis- and trans-nonachlor, heptachlor epoxide and BB-153), 18 showed statistically significant average yearly declines of − 4.4% (range: − 2.0 to − 10.8%/year) among subadult polar bears (i.e. females < 5 years, males < 6 years). For example, the ∑ PCB concentrations declined 2.7 fold from 22 730 ng/g lw (95% C.I.: 12 470–32 990 ng/g lw) in 1983–1986 to 8473 ng/g lw (95% C.I.: 6369–9776 ng/g lw) in 2006–2010. Similar but fewer statistically significant trends were found for adult females and adult males likely due to smaller sample size and years. Despite declines as a result of international regulations, relatively high levels of these historic pollutants persist in East Greenland polar bear tissues.  相似文献   

20.
Climate change is expected to be a major driving force of landscape in the coming decades. It will have a multitude of potential impacts that vary in intensity and effect according to region and sector. In the context of global warming, the climate of China has changed significantly in the recent 100 years. The reason for climate change in China is mainly due to irrational land use caused by human activities, which chiefly results in the rapid industrialization and urbanization process. Based on an assessment model, this research represents a picture of the impacts of climate change in six districts of Hangzhou region. The aim of this paper is to conclude, on the one hand, some of Hangzhou sensitivities in relation to the primary effects of climate change. On the other hand, a reflection is made on a methodology to formulate preconditions on a scientific basis for further research by design of integrated adaptation options for the future spatial developments in function to upgrade Hangzhou resilience in relation to climate change challenges.  相似文献   

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