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Abstract

Despite rapid evolution in international fisheries law and establishment of the exclusive economic zone (EEZ), straddling stocks still remain susceptible to heavy harvesting in high seas areas by distant‐water fishing states there by undermining coastal state management. The notion mar presencial (presential sea) has recently been proposed by Chile as a solution for the problem of straddling stocks. The presential sea concept was nationally designed and promoted to curtail such foreign fishing in areas adjacent to Chile's EEZ. This article examines the presential sea as a geostrategic concept, its justification for being, and the question of its permissibility under contemporary international fisheries law. Attention is also given to recent international developments that challenge the legal viability of the presential sea concept. The authors conclude that if this concept were to be widely adopted by coastal states, the traditional freedom to fish on the high seas might be severely compromised. The preferable legal solution is to work within the parameters set out by the 1982 UN Convention on the Law of the Sea, more particularly through bilateral negotiations between coastal states and fishing states, as well as regional fishery commissions that could manage activities in the region.  相似文献   

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Thomas A. Clingan. The Law of the Sea: Ocean Law and Policy. 1994. San Francisco: Austin and Winfield. 638 pp. ISBN 1–880921–37–5 (hardcover), $89.95. ISBN 1–880921–28–6 (softcover), $69.95  相似文献   

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Abstract

The consequences of the inevitable acceptance of extended jurisdiction and its impact on fisheries policy in the South Pacific are considered within the framework of the principles outlined at the Third Session of the United Nations Law of the Sea Conference. It is pointed out that the fisheries resources of the region considered are dominated by highly migratory species, particularly tunas, and that the management of the fisheries on these species and the conservation of the species themselves will require comprehensive regional cooperation. Considering the common interests of the developing countries of the region and their comparative lack of experience in fisheries management and in surveillance and enforcement capabilities, it is argued that a regional fisheries agency is required. A wide range of possible functions for such a body is discussed and a three‐phase approach to the development of the agency is proposed.  相似文献   

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The shift in marine resource management from a compartmentalized approach of dealing with resources on a species basis to an approach based on management of spatially defined ecosystems requires an accurate accounting of energy flow. The flow of energy from primary production through the food web will ultimately limit upper trophic-level fishery yields. In this work, we examine the relationship between yield and several metrics including net primary production, chlorophyll concentration, particle-export ratio, and the ratio of secondary to primary production. We also evaluate the relationship between yield and two additional rate measures that describe the export of energy from the pelagic food web, particle export flux and mesozooplankton productivity. We found primary production is a poor predictor of global fishery yields for a sample of 52 large marine ecosystems. However, chlorophyll concentration, particle-export ratio, and the ratio of secondary to primary production were positively associated with yields. The latter two measures provide greater mechanistic insight into factors controlling fishery production than chlorophyll concentration alone. Particle export flux and mesozooplankton productivity were also significantly related to yield on a global basis. Collectively, our analyses suggest that factors related to the export of energy from pelagic food webs are critical to defining patterns of fishery yields. Such trophic patterns are associated with temperature and latitude and hence greater yields are associated with colder, high latitude ecosystems.  相似文献   

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Abstract

This paper will set the international background for the evolution of the Exclusive Economic Zone (EEZ) concept in international law and in state practice. It will review the relevant provisions of the UNCLOS III and will discuss the extent to which they have or are likely to guide national practice in the future. The paper will also examine the Reagan Proclamation from an international legal perspective, as well as the possible impact of action taken by the United States in fashioning its EEZ on the stability of the EEZ concept internationally.  相似文献   

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1. Freshwater resource managers are increasingly obligated to consider the impacts of large river engineering projects on ecosystem services. We evaluated the effect of altered water regime from the operation of a large dam on the production of the downstream tropical floodplain fishery of the Kafue River, Zambia. We compared the benefits of increased hydropower relative to potentially lost fishery production. 2. We compiled a long‐term data set consisting of experimental gillnet catches, artisanal harvesting effort and monthly river flows for 25 years prior to and 29 years after the 1977 completion of the upstream Itezhi‐Tezhi Dam. As a metric of the flood regime, we calculated a canonical correlation score for each hydrological year before and after dam closure. For the period following dam construction, we used the Muskingum method of flood routing to estimate ‘no‐dam’ flows through the fishery area and downstream hydroelectric turbines at the Kafue Gorge Dam. 3. We compared 16 alternative models of catch per unit effort (CPUE) with and without an effect of water regime on fish population growth rate. Using the two best fitting models, we estimated the total observed fishery harvest and simulated ‘no‐dam’ fisheries harvest and found no significant effect of altered water regime on fishery production. 4. We estimate that the large upstream dam increases downstream hydropower production by about $18 million USD per annum. The reduction in fishery production caused by the altered water regime is not significantly different than zero, although the average reduction amounts to about $2.3 million annually. The total estimated value of harvest ranges from $1.3 million to $56 million annually. 5. Large observed declines in fish abundance over the 54‐year study period are attributed primarily with similarly large increases in total fishing effort in this mostly open‐access artisanal fishery. 6. These results contrast with other examples of the effects of flow alteration on fish, probably because levels of fisheries exploitation on the Kafue River are very high relative to better studied regions on other continents; our focus on the whole fish community; and the unprecedented length of the time series we considered. If the goal is to sustain fishery production, investments in altering flow regime are likely to be less effective than investments to decrease fishing effort.  相似文献   

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Abstract

This paper discusses the roles of ecological and economic information in the political and legal matrix of international fisheries. An argument is made for vesting exclusive management authority in a monopoly subject to a constraint that stocks not be depleted beyond the point of economic restitution. It is suggested that an appropriate authority be chosen by the criterion of the closest merging of ecological, economic, sociological, and political self‐interests. The reallocation of fishing effort by market dealings rather than by governmental negotiations is visualized as a means to reduce international conflicts over fishing rights. Precedents for the various elements of this model and the dangers inherent in it are discussed.  相似文献   

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Abstract

This paper examines the nature of the relationship between management, conservation, and cooperation in respect to EEZ fishing. The analysis is demonstrated through a discussion of the developments leading up to the creation of the South Pacific Forum Fisheries Agency (FFA). The paper examines and dismisses the criticism that the Agency does not fully meet the requirements of emerging international law. In addition to laying the foundations of the substantive argument, the conceptual and legal analysis presented here is also seen as a contribution to the wider debate about the scope and substance of the rights and duties of states in respect to EEZ fishing, especially in relation to highly migratory species.  相似文献   

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Summary A single locus model of the interaction between natural selection and artificial selection for a quantitative character in a finite population, assuming heterozygote superiority in natural fitness but additive action on the character, has been studied using transition probability matrices.If natural selection is strong enough to create a selection plateau in which genetic variance declines relatively slowly, then the total response to artificial selection prior to the plateau will be much less than that expected in the absence of natural selection, and the half-life of response will be shorter. Such a plateau is likely to have a large proportion, if not all, of the original genetic variance still present. In selection programmes using laboratory animals, it seems likely that the homozygote favoured by artificial selection must be very unfit before such a plateau will occur. A significant decrease in population fitness as a result of artificial selection does not necessarily imply that the metric character is an important adaptive character.These implications of this model of natural selection are very similar to those derived by James (1962) for the optimum model of natural selection. In fact, there seems to be no aspect of the observable response to artificial selection that would enable anyone to distinguish between these two models of natural selection.  相似文献   

15.
Electronic monitoring (EM) consisting of on-board video imagery and on-shore analysis, offers an alternative or supplement to at-sea observer programs in commercial fisheries. In the western and central Pacific Ocean (WCPO), where observer coverage in most tuna longline fisheries has historically been?<?5%, the advent of EM has been perceived as a tool for meeting international data collection and exchange obligations. However, the capability of EM to collect and support interpretation of records into data for all fields currently collected by at-sea observers is still under assessment. We use the Western and Central Pacific Fisheries Commission (WCPFC) as a case-study to evaluate the longline WCPFC regional observer programme minimum standard data fields, their current scientific application, the proportion of member countries exchanging data and the capability of EM technology to collect these fields. We identify that 78% of the longline fields can be collected with current EM technology, with 84% of these used in scientific analyses. For the 16% of fields not routinely used in scientific analyses, the introduction of EM may facilitate a sufficient increase in data availability to support their future use. Alternative tools would be required to collect fields that EM could not record to ensure data continuity and scientific rigour are not compromised. In examining the capability of EM in the context of WCPFC member state requirements under international law, we advocate for a holistic and integrated approach to the use of EM in future research and monitoring programs in both the WCPO and global longline fisheries.  相似文献   

16.
目的:本文探讨Flanker与Simon冲突间的交互作用,以及提示线索位置对其的影响。方法:实验通过将Flanker与Simon两种冲突融合于同一范式,采用斜线任务提高冲突难度,设计上下、左右和斜线三种位置提示线索,并根据其类型的不同将被试分为三组。统计分析冲突下的正确率与反应时数据,用重复测量方差分析得出两种冲突的交互作用,以及不同位置线索对其的影响。结果:总的来说,Flanker冲突和Simon冲突在反应时和正确率上都有显著效应。从正确率来看,上下位置线索时,Flanker和Simon冲突之间的交互作用显著;左右位置线索时交互作用不显著;而斜线位置线索时交互作用边缘显著。从反应时来看,对于三种位置线索,两种冲突间的交互作用都不显著。结论:融合在同一任务中的Flanker冲突与Simon冲突之间是否存在交互作用与提示线索的位置有关。  相似文献   

17.
Forty‐seven property owners in Entebbe, Uganda were questioned about vervet monkey activities on their property. Our main objective was to investigate the interactions between humans and vervet monkeys in an agricultural area adjacent to a forest zone. Other studies have reported that farms located within 300 m of a forested boundary probably incur the greatest risk of crop‐raiding. Two other factors that may influence susceptibility to vervet crop‐raiding were also examined: the types of crops grown and the types of direct preventative measures used. The effect of these two factors on vervet crop‐raiding is not straightforward. However, the distance a property is located from the forest edge is an important factor influencing vervet crop‐raiding. Surveyed gardens 200 m from the forest edge received significantly less crop‐raiding than farms located 100 m or 50 m (P = 0.040, < α = 0.05). We suggest that the development of nonagricultural activities on land directly adjacent to forested areas may reduce vervet crop‐raiding by deterring vervets from travelling greater distances from the forest edge due to increased obstacles or risks.  相似文献   

18.
The best known of the conflicts occurring in eusocial Hymenoptera is queen-worker conflict over sex ratio. So far, sex ratio theory has mostly focused on optimal investment in the production of male versus female sexuals, neglecting the investment in workers. Increased investment in workers decreases immediate sexual productivity but increases expected future colony productivity. Thus, an important issue is to determine the queen's and workers' optimal investment in each of the three castes (workers, female sexuals, and male sexuals), taking into account a possible trade-off between production of female sexuals and workers (both castes developing from diploid female eggs). Here, we construct a simple and general kin selection model that allows us to calculate the evolutionarily stable investments in the three castes, while varying the identity of the party controlling resource allocation (relative investment in workers, female sexuals, and male sexuals). Our model shows that queens and workers favor the investment in workers that maximizes lifetime colony productivity of sexual males and females, whatever the colony kin structure. However, worker production is predicted to be at this optimum only if one of the two parties has complete control over resource allocation, a situation that is evolutionarily unstable because it strongly selects the other party to manipulate sex allocation in its favor. Queens are selected to force workers to raise all the males by limiting the number of eggs they lay, whereas workers should respond to egg limitation by raising a greater proportion of the female eggs into sexual females rather than workers as a means to attain a more female-biased sex allocation. This tug-of-war between queens and workers leads to a stable equilibrium where sex allocation is between the queen and worker optima and the investment in workers is below both parties' optimum. Our model further shows that, under most conditions, female larvae are in strong conflict with queens and workers over their developmental fate because they value their own reproduction more than that of siblings. With the help of our model, we also investigate how variation in queen number and number of matings per queen affect the level of conflict between queens, workers, and larvae and ultimately the allocation of resource in the three castes. Finally, we make predictions that allow us to test which party is in control of sex allocation and caste determination.  相似文献   

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The conflict between humans and elephants in the central African forests   总被引:2,自引:0,他引:2  
Elephants and humans each suffer from the presence of the other when they occupy the same forests. Farmers risk losing their crops to elephants, while elephants are displaced by settlements, agriculture, roads and development projects. Elephants have also been hunted for ivory. The ivory trade in the equatorial forests expanded in the nineteenth century as Europe prospered, and then again in the twentieth century as the Far East prospered. Forest elephant numbers were depleted each time.
Elephants are unpopular in the forest zone, and increasing human populations combined with the spread of democracy in central Africa pose a major threat to their future. If elephants are to be tolerated by villagers living in the equatorial forests, the costs they impose must be reduced and the benefits to the rural populace must be increased. A three-pronged strategy is suggested, involving land-use planning, measures to mitigate crop damage, and programmes to enhance the value of elephants. Elephants could be viewed as assets if their importance in the forest ecosystem were recognized, if they were domesticated for logging or transport, or if their presence was one of the factors which attracted tourists to the forest zone. However, management strategies based on hunting have the best chance of conserving elephants because of the importance of hunting in the culture of the forest people. Sport hunting for trophies may bring the greatest revenues. Community wildlife-management programmes, where village councils make the decisions, could prevent overexploitation. There are no simple answers, however, because one form of management may conflict with the goals of another.  相似文献   

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