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1.
Exploited fish and shellfish stocks in European marine waters underlie the Common Fisheries Policy (CFP). The next round of reform of the CFP is due for completion in 2012. The exploitation at maximum sustainable yield (MSY) may be confirmed as the common environmental objective for good environment status (GES) of exploited fish and shellfish stocks of the reformed CFP and the Marine Strategy Framework Directive (MSFD). The foreseen time horizon to achieve or maintain GES by 2020 appears inconsistent with the World Summit on Sustainable Development UN agreement in 2002, which stipulates that maintenance or restoring of stocks to produce MSY be realized by 2015. The MSFD requires instead that by 2015 the national programmes of measures be designed in order to become operational the following year (2016).  相似文献   

2.
One of the most important goals in current fisheries management is to maintain or restore stocks above levels that can produce the maximum sustainable yield (MSY). However, it may not be feasible to achieve MSY simultaneously for multiple species because of trade-offs that result from interactions between species, mixed fisheries and the multiple objectives of stakeholders. The premise in this study is that MSY is a concept that needs adaptation, not wholesale replacement. The approach chosen to identify trade-offs and stakeholder preferences involved a process of consulting and discussing options with stakeholders as well as scenario modelling with bio-economic and multi-species models. It is difficult to intuitively anticipate the consequences of complex trade-offs and it is also complicated to address them from a political point of view. However, scenario modelling showed that the current approach of treating each stock separately and ignoring trade-offs may result in unacceptable ecosystem, economic or social effects in North Sea fisheries. Setting FMSY as a management target without any flexibility for compromises may lead to disappointment for some of the stakeholders. To treat FMSY no longer as a point estimate but rather as a “Pretty Good Yield” within sustainable ranges was seen as a promising way forward to avoid unacceptable outcomes when trying to fish all stocks simultaneously at FMSY. This study gives insights on how inclusive governance can help to reach consensus in difficult political processes, and how science can be used to make informed decisions inside a multi-dimensional trade-off space.  相似文献   

3.
As a signatory to the World Summit on Sustainable Development (WSSD), the European Union (EU) has made a commitment to maintain or restore fish stocks to levels that can produce the maximum sustainable yield (MSY), and where possible not later than 2015. So how has the EU's Common Fisheries Policy (CFP) fared in trying to achieve this objective? The development of the status of 41 commercially exploited fish stocks from the North East Atlantic, North Sea and Baltic Sea (FAO Area 27) was analysed together with the economic performance of the fleets exploiting those stocks. The analyses indicate that the exploitation status for many of the stocks has greatly improved during the last 10 years while the economic performance of the fleets over the same period has been highly variable. The main economic indicators (gross value added (GVA) and operating cash flow (OCF)) have gradually improved at a time when the general economic situation, which has a great influence on the markets, costs and purchase power, has worsened. While recognizing that much remains to be done to achieve the objective of the WSSD, the analyses indicate that actions implemented in the last decade under the CFP have led to an improvement in the status of many commercially important fish stocks and their fleets towards levels that are closer to those producing MSY.  相似文献   

4.
Maximum sustainable yield (MSY) has been adopted as the primary management goal by several inter-government fishery organisations, and in the United States it forms the cornerstone of federal fishery management policy. MSY became a strategic goal for the management of Europe's fisheries following the resolution of the World Summit on Sustainable Development in 2002 to restore or maintain fish stocks to MSY levels by 2015. Calculation of MSY requires information on the rate at which biomass increases through growth and reproduction and the rate at which it decreases through natural mortality and fishing. Population-selection, which measures the age-specific rates of fishing mortality, is a key component for the calculation of yield as a function of fishing mortality and MSY, yet selection rarely features in either management advice or sensitivity analyses. Effective management of selection can potentially lead to increases in long-term yield, but before taking action managers need to understand what long-term increases are possible. Using a hypothetical stock, equilibrium yield curves were calculated for three scenarios in which the shape of the population-selection curve varied. The results illustrate the potential extent of variation in MSY and the corresponding fishing mortality required to achieve it (FMSY) that may result solely due to changes in population selectivity. They show that relatively subtle changes in selection can produce substantial differences in MSY and FMSY. The results are discussed with specific reference to the development of long-term management targets and the mechanisms by which managers might try to influence population-selection.  相似文献   

5.
Korea's coastal and offshore fisheries have experienced reduction in their catch in the early 2000. The amount of catch from coastal and offshore fisheries dropped from 1.7 million tons in 1986 to 1 million tons in 2004. To address such catch reduction, fish stock enhancement programs have been constantly developed and implemented. However, as fish stocks have been estimated to decrease since 2000 in spite of various management measures, the Korean Government genuinely acknowledges the necessity to enhance fisheries productivity through the recovery of depleted fish stocks. Based on such acknowledgement, a fish stock rebuilding plan (FSRP) combined with conventional fish stock enhancement programs was established in 2005. For stocks which have shown drastic decrease, a FSRP was set up and promoted. So far, 10 FSRPs have been established and operated, and plan is being made to expand them to 20 species by 2012. The result of pilot projects shows that stocks have been increasing after the introduction of FSRPs. For instance, the catch per unit effort (CPUE) of sandfish in the East Sea has increased from 0.44 in 2005 to 0.78 in 2011. Consequently, fishing income has increased by 15%. The key lessons learned during the implementation of FSRP are: the causes for the decrease of stock vary and are complicated and it is necessary to adjust and eliminate some conventional policies that could have unforeseen negative impacts on fish stocks. The FSRP-based fisheries management policy in Korea carries great significance, for it has changed the focus of policy from simply maintaining the status quo to stock recovery and it allows relevant stakeholders to get actively involved in the procedures of establishing and promoting the plan, leading to effective implementation of the plan. The current FSRP is operated with species, but if it can be gradually expanded to encompass the whole ecosystem, it will greatly contribute to more effective management and fish stock recovery for all species in offshore and coastal waters surrounding Korea.  相似文献   

6.
剩余产量模型在不同渔业中的应用   总被引:4,自引:0,他引:4  
剩余产量模型因其简单和所需数据较少的特点为渔业资源评估广泛采用.本文应用目前常用的四种剩余产量模型对五种渔业下的渔业生物种群及北大西洋箭鱼种群xiphias gladius评估效果作了比较.四种剩余产量模型在渔业1中的评估效果较好,而在渔业2中的效果较差;Schnute模型在充分捕捞的渔业,如渔业3、4、5,尤其是在低生物量的渔业3中评估效果较好,但不适合评估未充分捕捞的渔业.Walters-Hilborn模型(W-H模型)适用于各种渔业,尤其是渔业1、4、5.在过度捕捞渔业中如渔业3、4,模型对参数q的估计较其它参数接近真值.在北大西洋箭鱼(xiphias gladius)渔业的评估中,W-H模型对MSY的估计约为14000吨,接近于Prager(1996)的结果.  相似文献   

7.
Most worldwide fish stocks are overexploited, and so exploited beyond the Maximum Sustainable Yield (MSY) and the Maximum Economic Yield (MEY). Not exploiting fisheries resources at MSY or MEY leads to the loss of production and rents from the fisheries. A large part of the EU fisheries are managed based on single species stock assessments; however, in reality, most species are caught together with other species and by different fleets. In multi-species and multi-fleet fisheries, single species assessments, and consequently MSY and MEY reference points, are often not valid, and so the catch recommendations. In this paper it is investigated the MSY and MEY estimation in multi-species and multi-fleet fisheries in comparison to single species assessments. Analyses are applied to the Bay of Biscay demersal fishery using the IAM bio-economic model. The impact of exploiting at MSY and MEY on the optimal effort allocation between fleets with different exploitation patterns and economic structures is analyzed. When accounting for the multi-species nature of the fishery, MSY landings are 0.4% to 2.7% lower than the single species simulations estimates. When accounting for the multi-fleet nature of the fishery, MSY landings are 27.2% to 30.2% higher than the single-fleet estimates. When considering the multi-fleet characteristics, MEY landings are 6.6% higher and profits are 66.5% higher than in the single-fleet simulation. Optimal effort at MEY is lower than at MSY, but when accounting for multi-fleet the optimal effort decreases for some fleets while increases for gillnetters. The results also provide an estimation of the profits at MEY (or costs of not being at MEY). Profits can be then up to 10.7 times larger than the current profits (256 million Euros compared to the current 24 million Euros).  相似文献   

8.
The dismal record of fisheries management worldwide is often blamed on managers' and scientists' bigoted pursuit of the flawed Maximum Sustainable Yield (MSY) objective. This paper aims at clarifying that MSY has never been a key element in the EU Common Fisheries Policy (CFP), and has not been for several decades the basis of scientific advice provided in support of that policy. The recent emergence of MSY in debates about the CFP might be a rhetoric response to international pressure rather than a willing change in policy. The major danger of assigning the notorious failure of the CFP to a wrong culprit, MSY, is to distract research efforts away from investigating the real causes that likely lay in the institutional set-up. Many objections against the reference points associated with MSY, as targets or limits, are well-founded but controversies among experts, when left unbridled, just provide the opportune climate for politicians to delay actions in the direction of reduced fishing impacts on fish stocks and marine ecosystems.  相似文献   

9.
An important component of science-based fisheries policy is the provision of habitat adequate for population renewal. In Canada, the Fisheries Act pays little attention to managing fish habitat, and was further weakened by changes enacted in 2012. Specifically, determining the role of fish habitat in contributing to fisheries and fish stock recovery is challenging when many stocks have severely declined and no longer occupy former habitats. This study compared the abundance of juvenile fish in coastal vegetated habitats before and after collapse or decline of groundfish stocks in Atlantic Canada. This comparison was done by compiling past studies that surveyed juvenile Atlantic cod (Gadus morhua) and pollock (Pollachius virens) in vegetated habitats across three provinces. Two studies were repeated, and one that already had post-collapse data was analyzed to quantify long-term changes in juvenile abundance. In all three cases substantial reduction in juvenile abundance coincided with declines in adult stocks. However, juvenile fish still occur in coastal habitats and could aid in adult stock recovery. The current version of the Canadian Fisheries Act requires presence of an ongoing fishery to trigger habitat protection. This is problematic as low fish abundance may lead to lowered habitat protection and potentially habitat degradation, with less or lesser-quality habitat for fish in the future. Thus, recommendations are made to repeal the 2012 Fisheries Act changes and enhance current fish habitat legislation. Using a precautionary approach for coastal fish habitat management, particularly in valuing its potential for fish stock recovery, would strengthen Canadian fisheries management.  相似文献   

10.
Cod and haddock are two of the “big 5” UK supermarket fish species and intrinsic to fish and chip shops nationwide. UK whitefish fleets produce a significant amount, however there is a reliance on imports to maintain supply. The UK is in a strong position to compete for raw material from Iceland and Norway given high prices paid for imports and investment by Icelandic and Norwegian companies in the UK. Regarding UK production of whitefish, the European Common Fisheries Policy landing obligation has introduced significant uncertainty. To avoid discarding of any quota stock, fishing may be stopped before all target stocks quota is reached. For demersal fleets, there is a transition period between 2016 and 18 where target stocks are introduced according to Advisory Council and EU agreement and Article 15, with all quota stocks from 2019. As the capacity of the fleets balance to the new regulations, supply will likely return and if maximum sustainable yield (MSY) is reached in 2020 then an increase in TACs from current levels is likely too. However, markets and industries can change in a short period. Particularly, most processing companies are small to medium size enterprises and those that concentrate on cod and haddock may have to adjust their business. Fleets could be resilient to such short term reductions in landings however this cannot be assumed. The competitiveness of producers will surely be affected in the short to medium term as a result.  相似文献   

11.
When the Regional Advisory Councils (RACs) were created during the last reform of the Common Fisheries Policy (CFP) in 2002, it was recognised that in addition to the five geographically orientated stakeholder lead advisory bodies, a separate RAC dedicated exclusively to pelagic fisheries was needed because of it being so distinctly different from other fisheries. Pelagic fishing is different mostly due to the fact that the targeted fish species behave in a unique manner by grouping in schools in mid-water unlike other commercially targeted fishes, which typically reside on or near the ocean floor. For this reason, as well as the fact that they are usually widely distributed, researching and managing this dynamic group of fishes across the borders of many countries requires a unique approach. Fortunately, despite these complexities, policy makers have succeeded to establish a reasonably well functioning management framework, which has lead to the situation that most pelagic fish stocks are harvested biologically sustainable. While a majority of Europe's fish stocks still need rebuilding, and the main aim accordingly is to reduce fishing mortality, the current focus for pelagic fish stocks is to improve the performance of already implemented Long Term Management plans in terms of their biological as well as social and economical objectives. This paper reflects upon experiences of the Pelagic Regional Advisory Council (PRAC) in its role as advisor to the EU institutions. Subsequently, in the context of ideas presented in the European Commission's Green paper, the authors discuss the future of the PRAC and conclude that its main development potential lies not with the current EU's CFP reform, but rather should be sought in a wider international context.  相似文献   

12.
基于渔业统计数据的南海区渔业资源可捕量评估   总被引:6,自引:1,他引:5  
科学确定海洋渔业可捕量是开展捕捞限额管理的前提和关键。南海区渔业资源种类繁多,无明显大宗经济鱼种,且产量统计不够完善,使得可捕量的量化评估较为困难。根据渔业产量统计数据,利用一种简化的产量模型对南海区渔业资源总可捕量以及11个重要经济类群的可捕量进行了评估。结果表明,南海区渔业资源最大可持续产量为308.6万t,总可捕量为246.9万~277.8万t。从11个重要经济类群的评估结果来看,这些类群在20世纪90年代后均遭受过不同程度的过度捕捞。目前状态较好,未处于过度捕捞状态的有蓝圆鲹和竹荚鱼、沙丁鱼类、马面鲀类、鲷类、鳓类和鲐类等6个恢复力较高的类群;而其他5个恢复力较低的类群,尤其是海鳗类和石斑鱼类,目前处于过度捕捞状态。  相似文献   

13.
Although overexploitation of commercial fish stocks in European waters has been in the public debate now for more than 20 years, the European Union has so far failed to implement sustainable fisheries management. Millions in subsidies paid to the fishing industry have led to significant excess capacity in the fishing fleet. Various feeble attempts to stop overexploitation of marine resources have failed. The cause is that fishing policy is highly dominated by short-term socioeconomic interests. There is an urgent need for a new fisheries management system in Europe that supports reductions in the fishing fleet, increases responsibility among fishers and guarantees long-term conservation of natural marine resources.Transferable rights to fish have proved a reliable and effective means of creating incentives to conserve marine resources. By strengthening individual fishing rights under flexible quota management systems, the EU Member States could, within the Common Fisheries Policy, make a significant contribution to conserving fish stocks, to reducing excess capacity and to raising the profitability of the fisheries industry. A closer look at existing reservations against a flexible management system shows most of the objections to be overstated or capable of resolution.  相似文献   

14.
Extensive criticisms of the management of marine fisheries periodically arise for a variety of reasons. While the complexity of the US fisheries management process is partially to blame, these reasons manifest themselves in statements that include a perceived decline in living marine resource abundance levels, a proposed change in the regulatory infrastructure, or improvements in stock abundance that some feel should allow for new entrants. Following these criticisms are calls to end the federal management process or at the very least the replacement of the fishery management agency leadership. These demands driven by rent seeking behavior use short-term declines in abundance as justification when the long-run abundance measures would have indicated improvements in stock abundance and achievement of management objectives. Empirical, long-run, stock abundance indices are estimated using synthetic demand methodology, based on bioeconomic fishery theory, applied in a general and partial equilibrium theory framework to determine if maximum sustainable yield (MSY) management targets have been achieved and maintained for four fisheries considered to be successfully managed and one characterized as a socio-economic disaster. The abundance of a fish stock is more influence by extra-market and extra-fishery forces than by fisheries managers who base allocation decisions solely on single species stock assessments.  相似文献   

15.
Ten European fish stocks recognised by the European Union as “outside safe biological limits” are considered in light of widespread reforms to fisheries legislation in 2013, particularly the legal responsibility to exploit these resources sustainably. Given that some of these stocks are – as of 2013 – fished at over 150% the recommended intensity and many have been outside of these limits for the entirety of their assessment history, the utilisation of traditional fisheries management measures of sustainability are questioned and tougher approaches such as “zero-catch” and long-term, expansive spatial closure scenarios are considered. Finally, the pervasive issue of data-deficiency (the status of 54% of European stocks) is briefly considered, with specific reference to the understudied West of Scotland and North Sea stock of European seabass (Dicentrarchus labrax).  相似文献   

16.
Most fisheries in China do not have maximum sustainable yield(MSY) estimates due to limited and poor data.Therefore, finding a common method to estimate MSY or total allowable catch(TAC) for fishery management is necessary. MSYs of three important fisheries in the East China Sea were evaluated through a catch-based model.Estimates for intrinsic rate of increase(r) and five levels of process error were considered. Results showed hairtail Trichiurus japonicas(Temminck and Schlegel) and small yellow croaker Larimichthys polyactis(Bleeker) fisheries experienced overfishing from the mid-1990 s to the early 2000 s, and the suggested TACs were 55.8×10~4 t and9.06×10~4 t, respectively. Decades of overfishing in wintering and spawning grounds of large yellow croaker Larimichthys crocea(Richardson) caused the fishery's collapse in the 1980 s, and it has not recovered until today.The Catch–MSY model generated similar estimated MSYs with other methods and may be a useful choice for the assessment of regional stocks in China.  相似文献   

17.
《Journal of Sea Research》2007,57(2-3):114-125
Many flatfish species are caught in mixed demersal trawl fisheries and managed by Total Allowable Catch (TAC). Despite decades of fisheries management, several major stocks are severely depleted. Using the Common Fisheries Policy (CFP) as an example, the failure of mixed-fisheries management is analysed by focussing on: the management system; the role of science; the role of managers and politicians; the response of fisheries to management. Failure of the CFP management could be ascribed to: incorrect management advice owing to bias in stock assessments; the tendency of politicians to set the TAC well above the recommended level; and non-compliance of the fisheries with the management regulations. We conclude that TAC management, although apparently successful in some single-species fisheries, inevitably leads to unsustainable exploitation of stocks caught in mixed demersal fisheries as it promotes discarding of over-quota catch and misreporting of catches, thereby corrupting the basis of the scientific advice and increasing the risk of stock collapse. This failure in mixed demersal fisheries has resulted in the loss of credibility of both scientists and managers, and has undermined the support of fishermen for management regulations. An approach is developed to convert the TAC system into a system that controls the total allowable effort (TAE). The approach takes account of the differences in catch efficiency between fleets as well as seasonal changes in the distribution of the target species and can also be applied in the recovery plans for rebuilding specific components of the demersal fish community, such as plaice, cod and hake.  相似文献   

18.
Long-term investment to drive the adoption of precautionary, adaptive and resilience-building fisheries management measures is urgently required, especially given the financially difficult transition period to reach sustainable fisheries. In this paper a case for investing in the recovery of large marine ecosystems is provided based on the future value of recovered fish stocks. It is argued that the current market-based sustainable seafood movement alone will not affect the scale of change needed and must be complemented by investment in fundamental conservation measures that will lead to the recovery of marine ecosystems and promote long-term sustainable use. A rationale for addressing the economically challenging transition period is provided and the basis of a new financial institution to finance the measures necessary for realising the economic, social and environmental benefits of large-scale fisheries reform is proposed.  相似文献   

19.
In Europe, 88% of fish stocks are being fished beyond Maximum Sustainable Yield and 30% of stocks are outside of biological limits. The blue whiting fishery is also following a consistent trend of a declining, and the EU recently adopted a 93% quota decrease for this species. Despite the abundant literature related to genetic aspects of population structure of aquatic resources, few studies have specifically addressed the link between fisheries management and population genetics. Given potential differences in the behavior of different subpopulations, population genetics has great relevance in the correct interpretation of the evolution of stocks. Ignoring the congruence of spatial scales between the population structure of fish species and management units can result in reduced productivity and local reduction of populations.  相似文献   

20.
The failure of the command and control approach to fisheries management has encouraged governments to look for new ways of balancing the requirement to conserve fish stocks and yet maintain a flow of benefits that will meet economic and social targets. In the quest to establish a system for sustaining production in the Common Pond, the European Union (EU) has begun to investigate alternatives to the current management system. This research paper examines the problems associated with the current management regime operating in the EU in the light of alternatives for managing the fisheries. The research seeks to establish whether, given the serious problems confronting the EU's fishing industries, fishermen would be prepared to accept change and offer their ideas and support to develop an alternative management system. The research draws on the opinions of fishermen from Shetland and discusses the findings gained from interviewing key informants in conjunction with the results of an opinion survey of skippers and boat owners.  相似文献   

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