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1.
The authors concentrate on four aspects of environmental alteration of the Sea of Azov. First, they trace the Azov's problems back to Soviet resource-use conflicts. Second, they present several examples of anthropogenically induced environmental disruption of the Azov's ecosystem. Third, modeling is utilized to project possible future salinity conditions within the Azov. Fourth, in their attempt to evaluate the various ameliorative efforts that have been made or are being proposed, they challenge the overall ecologic-economic effectiveness of the proposed dam across the Kerch' Strait designed to regulate the salinity of the Azov. Finally, they conclude it is unlikely that the Azov ever will be returned to its previous “natural” condition. This article should be read in conjunction with Pecherin's article also in this issue of Soviet Geography. (Illustrations by Elinore Mathews, University of Washington, Seattle.)  相似文献   

2.
In an effort to stabilize the declining level of the Caspian Sea, it has been proposed that evaporation from the water surface be reduced by decreasing the size of the sea through construction of a dam in the northern portion. Data on the geology and hydrology of the Caspian Sea bed suggest that the construction of a dam might have undesirable consequences not only for the northern fisheries basin but for the sea as a whole. The findings are based on the presence of salt domes on the bottom of the northern Caspian Sea. An influx of highly mineralized subsurface waters along faults associated with the salt domes as well as leaching of salt from the structures themselves may threaten to raise the salinity of the northern fisheries basin to intolerable magnitudes. The presence of a man-made dam, in the author's view, would also interfere with the natural circulation of water, threatening contamination of deeper layers of the Caspian Sea with hydrogen sulfide, as has happened in the case of the Black Sea. [For a discussion of the Caspian Sea problem, see Soviet Geography, November 1972.]  相似文献   

3.
The increasing demand on water in the Soviet Union and the problem of assuring water quality require the construction of long-term water-management balances by drainage basins. These balances, based on predicted demand and water availability, would suggest the need for water-management projects within basins and interbasin transfers. Water needs would be evaluated both in terms of water requirements by categories of users and in terms of water quality. The most crucial regional problems involve the increasing shortage of water in Central Asia (with the prospect of interbasin transfer from Siberia) and in southern regions of the European USSR (with the problem of diverting water southward from the northern runoff slope). The Caspian Sea is expected to require a supplementary inflow of 80 to 100 cubic kilometers a year by the end of the century if the decline of its waterlevel is to be arrested. But southward diversion of northern waters is not expected to add more than 50 to 70 km3 at best, with a possible saving of an additional 10 to 20 km3 through decline of evaporation from a reduced Caspian Sea surface. The preservation of conditions in the Sea of Azov, the Aral Sea and Lake Balkhash pose additional water problems. [The senior author died in October, 1974].  相似文献   

4.
Marine fish bones are abundant components of human food remains at prehistoric sites in the eastern Tropical Pacific. Their quantification and interpretation in terms of human procurement strategies have been hampered by the use of large-meshed sieves and by the obstacles presented to faunal experts by fish taxonomic diversity. Since many important food fish families are speciose, this paper emphasizes the importance of species-level identifications. Making extensive use of Spanish-language articles on fish distribution and ecology, and the commercial and artisanal fisheries literature, it identifies groups of nearshore and littoral fish species that show greater and lesser tolerance for hard substrates (reefs and rocks), estuaries and coastal lagoons, and deeper clearer waters farther offshore. Most of the regional archaeological sites were located near estuarine habitats. The drab-colored fish they attract are generally poorly known. Hence, a particularly detailed analysis is offered of fish behavior within low salinity coastal inlets. Fourteen archaeofaunal fish samples from Costa Rica, Panama, and Ecuador are evaluated in the light of the environmental information generated by the biological and fisheries surveys. It is concluded that most sites have a broadly estuarine orientation and that the input of hard substrates is everywhere <10%. Two sites, Salango, in Ecuador, and Vidor, in Costa Rica, exploited epipelagic fish that swim in large shoals and deep water demersal predators. Sites situated more than 10 km from the coast exploited a wide variety of marine fish. In Parita Bay, Panama, a comparison of fish faunas from Cerro Mangote (6000 B.P.) and Sitio Sierra (1800 B.P.) elicits the hypothesis that regional fishing strategies shifted between these dates from a shore-based, netless strategy to a more complex one that incorporated fine-meshed gill-nets and watercraft.  相似文献   

5.
In view of the declining inflow into the Aral Sea, alternative proposals are advanced to save this inland sea by reducing its area as well as its salinity levels. The proposals involve the closing off of some portions of the sea, notably the Little Aral in the northeast and the Western Aral, from the large shallow eastern portion. Some portions of this fragmented sea would then be treated as active bodies of water with a throughflow regime, discharging surplus waters of high salinity into other portions, which would be allowed to become salt marshes. Various combinations of active water areas and residual water areas are examined, and possible trends in waterlevel and salinity are projected to the middle of the 21st century.  相似文献   

6.
Archaeological fish bones reveal increases in marine fish utilisation in Northern and Western Europe beginning in the 10th and 11th centuries AD. We use stable isotope signatures from 300 archaeological cod (Gadus morhua) bones to determine whether this sea fishing revolution resulted from increased local fishing or the introduction of preserved fish transported from distant waters such as Arctic Norway, Iceland and/or the Northern Isles of Scotland (Orkney and Shetland). Results from 12 settlements in England and Flanders (Belgium) indicate that catches were initially local. Between the 9th and 12th centuries most bones represented fish from the southern North Sea. Conversely, by the 13th to 14th centuries demand was increasingly met through long distance transport – signalling the onset of the globalisation of commercial fisheries and suggesting that cities such as London quickly outgrew the capacity of local fish supplies.  相似文献   

7.
The Neolithic site Ri??ukalns in the Lake Burtnieks/River Salaca area in northern Latvia is the only freshwater shell midden in the eastern Baltic Sea area. An excavation carried out in 2011 revealed an intact stratigraphy with alternating layers of unburnt and burnt mussel shells and yielded various kinds of archaeological finds, among them several thousand fish remains. To gain an understanding of the fish species and specimens caught by the Neolithic settlers, and to discern any temporal development in the fish species composition, we analysed fish remains from different sections and layers. Results from both the archaeozoological and stable isotope data, give evidence for a change in the relevance of fish species during the period of use, and they also provide information for reconstructing the former river and lake hydrology in the vicinity of the midden. The Stone Age landscape seems to have been very similar to the present situation, so that the study area has been an extraordinarily stable ecosystem for more than 5000 years. Comparisons with the results of recent monitoring programmes, long-term changes since Medieval times, and written sources from the 18th century, show that the fish species community is almost unchanged since the Stone Age. This underlines the importance of the region in nature conservation.  相似文献   

8.
The Roman wreck found off Grado, not far from the city of Aquileia in the north Adriatic Sea, was recovered in 1999. The ship carried various kinds of amphoras with processed fish. A lead pipe, inserted in the hull near the keel, is curious evidence which the authors try to explain. The pipe could be connected to a piston‐pump to suck water. A theoretical reconstruction demonstrates how this apparatus could work and that it could be used to feed a tank to allow trading in live fish over a long distance. © 2011 The Authors  相似文献   

9.
A set of principles for a geographical research program relating to the future impact of major interbasin water transfers is outlined. Such a program, evaluating the impact of proposed tranfers both in the European USSR and in the Midland Region of Western Siberia, Kazakhstan and Central Asia, should be based on the following considerations. Noneconomic criteria, such as the environmental impact of water transfers, must be given as much attention as economic and engineering criteria. Experience suggests that any measures designed to protect or ameliorate the environment, for example, inland fisheries, should precede actual water-project construction by at least 15 to 20 years. North-south transfers should be so designed as to benefit both the northern region, from which water is to be withdrawn, and the southern region, where water resources are to be enhanced. The problem of interbasin transfers should be accompanied by a program of intensification of water use, measured by a reduction of water input into the economy per unit of output. Water use can be intensified by such measures as shifting grain production from south to north and building irrigation reservoirs in Central Asian mountains to regulate runoff.  相似文献   

10.
Summary.   This paper will explore the role of the Isle of Man in the prehistory of the Irish Sea area through an examination of its changing islandscape from the Neolithic through the Iron Age. It was far from insular during prehistory, but the social and economic interactions of prehistoric Manx people around the Irish Sea and beyond were heavily affected by their water-bound environment. The way that the prehistoric Manx perceived their boundaries and their coastal situation is reflected in their ritual and social landscape, their preferential use of coastal areas for monumental architecture, and in the choices they made with regard to the island landscape they inhabited. This culturally constructed sense of islandness allowed the prehistoric Manx people to maintain distinctive local cultures while still playing an active role in the larger Irish Sea region.  相似文献   

11.
A specialist in loess geomorphology and arid-zone hydrology distinguishes three categories of factors accounting for waterlevel changes in the Aral Sea. She judges the most significant to be changes in inflow resulting from changes in the course of the Amudarya, the more important of the two tributary streams. The Amudarya at various times emptied into the Sarykamysh depression, southwest of the Aral Sea, giving rise to a flow of water through the now dry Uzboy channel to the Caspian Sea. Climatic change, involving alternations of wet and dry cycles, is said to have accounted for only minor water level fluctuations, of the order of 4 to 6 m, against the background of the major fluctuations produced by the Amudarya course migrations. Human activity, notably irrigation, is regarded as having become significant only in modern times as a result of an expansion of irrigation works. The present abrupt decline in the Aral waterlevel (6 m from 1960 to 1977, including 2 m in the last three years) is attributed to the combination of a dry climatic cycle and greatly increased use of water for irrigation.  相似文献   

12.
Chris Sneddon 《对极》2007,39(1):167-193
This paper examines recent conflicts over freshwater fisheries in Cambodia using the notion of accumulation through dispossession as a conceptual starting point. Despite a recent material turn, theoretical literature on the political economy of the environment has only partially incorporated an ecologically nuanced view of nature into analyses of its transformation under processes of capital accumulation. The biophysical characteristics of riverine fisheries are predicated on the ecohydrologic dynamics of water flows, and these characteristics dictate strategies of appropriation for both subsistence and commercial use. The complexity of these material characteristics is compounded in the case of Cambodian fisheries, where an array of state‐ and market‐driven processes promote the dispossession of resources and constrain the livelihood opportunities of rural communities dependent on fishing. Theories of capital accumulation and how accumulation induces socioecological conflicts can be very useful, firstly, for explaining the origins of environmental conflicts and, secondly, for grounding the analysis of such conflicts in the politics of accumulation as mediated by state actors. Conversely, theoretical framings of primitive accumulation must examine the “things” being accumulated (eg riverine fisheries) in far more biophysically specific ways, and must recognize the circuitous pathways, particularly in cases involving developmental states, that strategies of accumulation follow.  相似文献   

13.
Canada cannot manage Straddling fish Stocks, which extend beyond Canadian waters into the high seas, without an effective foreign fisheriespolicy. This article examines the politics andfate of two such Stocks in the Northwest Atlantic; cod and Greenland halibut. More successful management of Straddling Stocks, I argue, can be achieved if enforcement policies eure conducted within theframework of multilateral ftsheries organizations. By appealing to the rules and Information provided by these Institutions, Canadian governments canpursue more aggressive and proactive fisheries policies while maintaining a high level ofpolitical support at hörne and abroad.  相似文献   

14.
Although both the Caspian and Aral Sea basins are affected by fluctuations in the general moisture conditions affecting the Northern Hemisphere, the two drainage basins react differently to identical moisture changes both over the long term and over the short term. Over the short term, a shift in wet periods has been observed between the European part of the USSR, which contains the Volga basin draining into the Caspian, and western Asia, which contains the Aral Sea drainage basin. Since there is a direct relationship between general moisture conditions and level changes, the short-term level fluctuations would be heterochronous (out of phase) in the two seas. Over the long term, the comparison is complicated by the fact that Caspian drainage derives mainly from snow meltwater in the Russian plain while Aral Sea drainage derives from a combination of snow and glacier meltwater. Glacier runoff tends to increase in dry, warm periods and to decrease in wet, cold periods of glacier growth, while snow is related directly to general moisture conditions.  相似文献   

15.
The fish remains are described that were found at the bottom of an Early Roman ceramic jar from Aila Aqaba, Jordan. The bones, representing the gill apparatuses of at least 33 medium-sized tunas (Auxis; Scombridae) and a single individual of a lizardfish (Trachinocephalus myops; Synodontidae), are believed to correspond to haimation. This highly prized fish sauce, documented previously only from ancient textual evidence, was typically made from the gills and the entrails of tunnids to which salt was added. The sauce was not imported from the Mediterranean or the Black Sea, but made from local Red Sea fish as shown by the zoogeographical distribution of the lizardfish that is considered as stomach content of the tunas. Because the fish bones were found in a locally produced jar and because the calculated volume of the haimation that the bones represent corresponds more or less to the volume of the jar, it is concluded that this high-quality garum was produced in this container at Aila itself.  相似文献   

16.
The growth increments of otoliths and vertebrae of plaice (Pleuronectes platessa) derived from a 15th century single depositional event at Raversijde (Belgium) are analysed with the aim of reconstructing (a) the age distribution of the population, (b) the season of capture, and (c) the growth rate. Otoliths and vertebrae give slightly different age distributions but it is possible to arrive at similar seasonality estimations in both structures when information from the literature and our own data from monthly captures of plaice from the North Sea are taken into account. These modern data show that the timing of annulus formation in otoliths and vertebrae is more or less similar. Back‐calculations on vertebrae and otoliths yield similar growth curves. The age distribution, the edge condition of both vertebrae and otoliths, and the growth rate obtained on the material from Raversijde all show that the plaice from the studied assemblage were captured during spring in the southern part of the North Sea. Vertebrae are commonly preserved in archaeological sites whereas otoliths rarely survive. Although they are more difficult to read than otoliths, vertebrae of plaice can be used for growth increment analyses, and the growth rates obtained from vertebrae from archaeological sites can, therefore, be compared in the future to growth data from modern otoliths studied in sea fisheries research. Archaeozoological material predating industrialized fishing since the 19th century can hence serve as a reference in the study of the compensatory response of commercially important species to heavy exploitation. Copyright © 1999 John Wiley & Sons, Ltd.  相似文献   

17.
This rich collection analyzes science in the archives over the past several thousand years. The chapters work together to tell stories of ambitious attempts to provide timeless data for science, which will be used for generations to come—ranging from ancient astronomy to geology to life‐logging and the development of web search. They also demonstrate convincingly that archives are powerful forces across the sciences—every science discussed has an archival base—which partly determine what kind of general knowledge claims can be made by future generations: it is hard to read an archive askance. The collection works best as a series of individual chapters, though some work is done to indicate where they speak to one another. It is a pity that there was not more input from archivists themselves in the project: their noninclusion means that some archival issues (especially what goes on with data after it gets into the archive—how it gets cleaned up, changed, reorganized) are treated somewhat lightly. The collection does provide a very useful set of tools for thinking about scientific archives. It is also an excellent introduction to the peculiarities of scientific archives—one that reflects back on the use of archives in history in general.  相似文献   

18.
The Lacy-Shellard index of driving rain is found too rough because it ignores wind direction and relies on annual means of precipitation and wind speed. A more refined driving-rain index is proposed as the product of total precipitation and the frequency of wind speeds of more than 5 meters per second. A study based on stations in the European USSR suggests that 30 to 40 percent of total precipitation strikes walls and other vertical surfaces north of Lat. 55°N, but that the percentage rises to about 70 percent along the coasts of the Barents Sea, the Baltic Sea and the Gulf of Finland. A technique is proposed for measuring the amount of precipitation striking walls of varying exposure. The amount is obtained by multiplying the total precipitation by the frequency of wind directions on rainy days.  相似文献   

19.
This article examines the fish trade between Denmark and Britain, focusing on the 1933 bilateral trade agreement. Britain was the main export market for Danish fish, achieving a significant market share. Import penetration exacerbated British concerns about competitiveness that had emerged during the 1920s. While British protectionism saw the introduction of tariffs and quotas, which nominally reduced Danish imports by 10%, the Danes accommodated restrictions through exporting semi-processed fish. This article details trends in fish imports from Denmark, examines the national positions in negotiating the trade agreement, and considers how each country's fishing industry responded to its implementation. It draws two principal conclusions. First, that the significance of trade in the development of the interwar fisheries requires greater consideration in historical accounts. Second, that the Danish industry more effectively accommodated the new trade regime than the nominally protected British fishing industry.  相似文献   

20.
This paper explores the potential of stable isotope analysis to identify the approximate region of catch of cod by analysing bones from medieval settlements in northern and western Europe. It measures the δ13C and δ15N values of cod bone collagen from medieval control samples collected from sites around Arctic Norway, the North Sea, the Kattegat and the Baltic Sea. These data were considered likely to differ by region due to, for example, variation in the length of the food chain, water temperature and salinity. We find that geographical structuring is indeed evident, making it possible to identify bones from cod caught in distant waters. These results provide a new methodology for studying the growth of long-range trade in dried cod and the related expansion of fishing effort—important aspects of the development of commercialisation in medieval Europe. As a first test of the method, we analyse three collections of cod bones tentatively interpreted as imported dried fish based on a priori zooarchaeological criteria. The results tentatively suggest that cod were being transported or traded over very long distances since the end of the first millennium AD.  相似文献   

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