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1.
Pacific bluefin tuna (PBF) (Thunnus orientalis) is commercially important in the North Pacific Ocean. Although its stock has been relatively low for decades, international discussions on a long-term management framework, including the definition of a limit reference point (LRP), have only recently started. This paper argues that an LRP for PBF could be developed by determining a biomass level that would prevent recruitment overfishing. First, it reviews the development of LRPs for various tuna species and demonstrates that most of these limits are not necessarily based on biological information on the respective species. Then, the current management of PBF is also reviewed as background information for considering an LRP for PBF. Finally, a variety of simple analyses of the stock–recruitment relationship of PBF are conducted to find a biomass level that would prevent recruitment overfishing—i.e. an LRP below which stocks should not fall. It is concluded that, for the first time to our knowledge, defining such an LRP for a tuna species is possible (about 30 thousand tonnes or 5% of estimated unfished spawning stock biomass in our calculation). Not only is the LRP based on actual experience, but also the logic behind it would be easier for stakeholders to understand than the theoretical LRPs used elsewhere. This LRP should be useful in future in more comprehensive management framework, such as one through management strategy evaluations, in which stakeholder involvement in decision-making is crucial.  相似文献   

2.
Managing overcapacity in small-scale fisheries in Southeast Asia   总被引:3,自引:0,他引:3  
It is now almost universally accepted that most of the nearshore fisheries in Southeast Asia are overfished. It is also accepted that overcapacity is one of the leading causes of this overfishing. The problem of addressing overcapacity in small-scale fisheries in Southeast Asia is much more complex than that of reducing overcapacity in industrial fleets. In order to manage capacity, managers need to measure and understand how much capacity currently exists in the fishery and what is the desirable level of capacity that best meets the set of management objectives. The only feasible solution to overcapacity may be based on a coordinated and integrated approach involving a mixed strategy of resource management, resource restoration and conservation, livelihoods and economic and community development, and restructured governance arrangements. The reduction of overcapacity implies an increased focus on people-related solutions and on communities.  相似文献   

3.
This paper uses a quarterly, game-theoretic model of the Northeast Atlantic mackerel to study the fishing strategies of five players: the EU, Norway, the Faeroe Islands, Iceland, and the international fishery on the high seas. Data on the spatial distribution of fish catches (1977–2011) are used to model changes in the distribution of the mackerel stock. The Nash equilibrium solutions predict a severe decimation of the stock through overfishing, either by parties (Iceland, the Faeroe Islands) that refuse to cooperate or by a general absence of cooperation. There is a wide discrepancy between this prediction and reality, as the stock seems, at most, only moderately overexploited, despite non-cooperation by Iceland and the Faeroe Islands. It is conjectured that these parties, and others, may engage in a degree of quasi-cooperation that falls somewhat short of full cooperation but avoids the extreme destruction of the Nash equilibrium. This tacit cooperation can be seen as being maintained by a mutually assured destruction of the fisheries of all parties in case they go to the logical extremes of non-cooperation.  相似文献   

4.
Dag Standal  Bernt Aarset   《Marine Policy》2008,32(4):663-668
Since the introduction of quotas and licences as important management tools, Norway has insisted on an individual vessel quota regime (IVQ). The main argument has been to avoid market-based transactions of quotas and vessels and secure stability in regard to a diverse fleet structure and decentralized ownership of scarce cod resources. Thus, an individual transferable quota system (ITQ) with a high degree of transactions and the potential for a heavy concentration of quota ownership and fewer vessels has never been an alternative. However, since the late 80s, the trawler fleet has been trapped within a web of unprofitable overcapacity. Within the frame of a closed management regime and a path-dependent IVQ system, the quota regime has been forced towards a market-orientated system for transactions. In this article, we analyze the Norwegian IVQ system and discuss whether the aggregate effects of the IVQ regime are congruent with the models’ profound ideals.  相似文献   

5.
In this paper, the authors analyze a wide range of recreational management strategies for their impacts on red snapper yield, economic surplus and the fish stock. Simulating a wide range of policies, the authors find Data Envelopment Analysis (DEA) inspired policy efficiency frontiers that lead to finding those management strategies that offer the greatest level of economic surplus for any biological target, looking at both the east and west Gulf of Mexico fisheries. Red snapper has been declared overfished since 1988 and the 2005 SEDAR 7 stock assessment declared red snapper were overfished and undergoing overfishing. In November 2009, the update of the assessment declared that overfishing was no longer occurring but that the red snapper stocks needed to be rebuilt. In this analysis, it was found that red snapper are neither overfished or undergoing overfishing. The main difference between the present model and the SEDAR 7 model is that the latest model uses a higher mortality rate for juveniles and a density dependent model. The authors also suggest that the east and west should be managed as separate units.  相似文献   

6.
Up to one-third of commercial fishery stocks may be overfished at present. By analyzing catch trends and applying an empirical relationship derived from stock assessments, this article tracks the geographic spread of overfishing at the country level in terms of lost catch and lost revenue, from the start of industrialized fishing in 1950-2004. The results tell a cautionary tale of serial depletion to meet the ever-rising demand for fish. Examining country losses with respect to fishery management reveals that overcapacity and excess fishing effort are widespread, but also that recent trends towards sustainability can stabilize or reverse losses (e.g. for Norway, Iceland, the US, Canada, Australia, and New Zealand). Global trade effectively masks the successive depletion of stocks, so that without decisive action to reduce fishing effort, many more stocks will suffer and undernourishment impacts for the major exporting, food-deficit nations will only magnify.  相似文献   

7.
An age-structured population model was used to examine the variability of yield created by randomly fluctuating recruitment success in the South African anchovy Engraulis capensis stock. Three different harvesting strategies were examined: (1) constant age-specific pattern of fishing mortality, (2) constant quota with effort limitation and (3) annual quota adjustments by means of an F msy procedure. Variable recruitment was generated by a stochastic stock-recruit relationship, and mean yields, mean spawner biomasses and probability distributions of yield were calculated at each exploitation level after 150 projections from the population structure of anchovy in 1981. Under conditions of constant fishing mortality, the variability of yield increased continuously as the exploitation rate was increased. The maximum average yield (MAY) is the stochastic equivalent of the maximum sustainable yield (MSY) of deterministic models, but an attempt to sustain this MAY by a constant quota resulted in a very high risk of stock collapse. An Fmsy policy based on pre-season adult biomass resulted in more variable yields than were obtained at the equivalent constant fishing mortality at age. Stability of yield therefore demanded the acceptance of lower average yields than could be attained in the long term by quota adjustment. It was considered that the South African purse-seine industry could not cope with the wide fluctuations of yield necessary to attain MAY. Specific management policies sufficiently robust to withstand both fluctuating recruitment success and the uncertainties in the parameters of working population models would be required.  相似文献   

8.
《Ocean & Coastal Management》2006,49(5-6):332-341
Jamaica's industrial fishery for queen conch (Strombus gigas) has produced a substantial amount of much-needed foreign exchange and for at least 10 years has been the most valuable component of all commercial marine fisheries activities. Since its inception in 1990 it has grown tremendously and may now be at some risk of collapse, due to problems including, among other factors, overfishing, poor enforcement, foreign poaching and under-reporting of catches. This paper examines and analyzes the problems relating to management of the conch fishery and speculates on its future. The main problems are overfishing by licensed fishers who take more than permitted, and serious poaching by industrial vessels mainly from Honduras, which exploit poor high seas enforcement by Jamaican authorities. For nearly two years the official fishery was closed due to legal issues. During closures, considerable foreign poaching occurred. The paper suggests that increased roles for the coast guard, continued quota reductions, and the Convention on International Trade in Endangered Species of Flora and Fauna (CITES), could be the best options for sustainability.  相似文献   

9.
Identifying competing interests and potential claims to a new marine resource, the plankton redfeed, which may be central as a solution to diminishing supplies of marine oils world wide, is critical prior to a commercial harvest thereof. The competing interests are found to be between those Norwegian fisheries organization taking an encompassing view of fisheries interests and those wanting more focus on the well-being of the coastal fishermen. Working within a corporatist setting, it is found, that interest organizations in Norway are included comprehensively by the national government in the decision-making process, but that the main group having the most power is Norges Fiskarlag, which will draw the quota distribution of a future redfeed harvest off shore and away from the coastal fishermen.  相似文献   

10.
New Zealand's quota management system (QMS) was introduced in 1986 to enhance the sustainability of New Zealand's fishery. This paper examines trends in quota and catch share concentration across a range of important fish stocks. It demonstrates that continuing concentration is occurring in the ownership of quota for deepwater species. At the same time there has been an increase in participation by small scale fishers in the inshore fishery. This appears to be driven by the introduction of the Annual Catch Entitlement (ACE) regime, allowing annual catch shares to be accessed at reduced transaction cost.  相似文献   

11.
Despite the increasingly positive reviews of individual transferable quotas (ITQs), few studies have considered how quota leasing activities can reduce the economic benefits to society and to fishermen operating under the ITQ fisheries system. This analysis reveals negative economic impacts of ITQs previously overlooked by examining the extent of quota leasing and the relationship between the catch value, the cost of fishing, and the quota lease price in the BC halibut fishery, long considered a poster child for ITQs. Findings challenge assumptions of economic theory used to promote the benefits of ITQs.  相似文献   

12.
A feasibility study was conducted on the impacts of the new Common Fisheries Policy (CFP) rules requiring catches in regulated fisheries to be landed and counted against quotas of each Member State - the landing obligation (LO), and that catch of species subject to the LO below a minimum conservation reference size (MCRS) be restricted to purposes other than direct human consumption. The aim was to estimate the level of discarded fish likely to be covered by the new rules, the impact of the rules on EU fisheries and the regulatory challenges and responses to them. Data from EU's Scientific, Technical and Economic Committee on Fisheries (STECF) database were analysed to estimate the volume of unwanted catches produced by EU fisheries. Views were sought from policy officials and fisheries scientists through a questionnaire on the implications of the LO and the control of fisheries across Member States, and the potential adjustments that might be needed. Findings show that 11% (44,000 t) of the total catches of EU countries from which data were available are of fish under MCRS. The species with the highest volume of undersized discards associated with the lowest quota, which would potentially restrict the fishing opportunities for other quota species (i.e. choke species), are plaice and haddock with 18,000 and 14,000 t of undersized fish respectively, followed by whiting and cod with 5000 and 6000 t of undersized fish respectively. Discards data shows that the Netherlands, United Kingdom, France and Belgium will be most affected by landings for non-human markets. Findings also show that existing infrastructure at landing ports in all Member States is limited because there are currently limited facilities in place to handle animal by-products produced by the catching sector. Policy officials maintained that while they could support the fishing industry through funding programmes, it is the responsibility of fishers to ensure they have the right infrastructure to handle unwanted catches. The expectation is that the LO combined with the restriction to non-human consumption purposes will encourage fishers to internalise the costs of catching unwanted fish and motivate them to avoid unwanted catch. This will be realised if sufficient flexibility is given to fishers to find their own solutions to reducing unwanted catches. It is concluded that gear technology measures exist to enable the regulated fisheries to increase gear selectivity.  相似文献   

13.
Why do fishers break rules? And why do they follow them? The answers to these pertinent questions could contribute to reducing overfishing, stock decimation, environmental degradation, economic losses and community failures. This explorative paper presents findings from a nationwide survey among Swedish fishers, who were asked what, in their opinion, would justify non-compliance, why fisheries management regulations are not being respected, and what might help improve the situation. The survey was conducted to test four inducements often suggested in the literature: Fishers’ compliance/non-compliance is based on (a) their own benefit, (b) whether they feel morally compelled to do one way or another, (c) whether compliance is believed to create a negative impression among peers and (d) whether they accept the justification given for introducing the rules. Among other things, the study finds that the moral motives of law-abidingness and peer group solidarity rank the highest among the reasons for compliance, that large-scale fishers are more concerned about deterrence than small- and medium-scale fishers and also that co-management experience makes fishers less inclined to accept non-compliance by fishers who seek to boost their income.  相似文献   

14.
This paper analyses effects of a shift from input to output controls in Australia's Southern Shark Fishery. We show that the use of two management tools—individual transferable quotas and a “partnership approach”—was flawed and argue that primary contributing causes were the unjustified expectation that quota management would serve as a ‘technical fix’ to a variety of presumed problems, the discounting of social effects and the extreme lack of stability in the organizational structure within which this fishery was situated.  相似文献   

15.
Declining catches are typically taken to be a warning sign of overfishing. But in fact, many such declines have been driven by recruitment changes unrelated to stock size, as evidenced by the failure of stocks to recover after reduction in fishing or recovery despite the failure to reduce fishing. Given a declining pattern, supposedly precautionary decisions to reduce fishing should be treated as experimental management options with a high probability of not resulting in the desired recovery to more productive stock sizes. Simple decision tables can be used to compare such experimental options to “wait and see” options that do not involve fishing reductions. A case example with a grouper fishery in Kuwait demonstrates that experimental effort reduction may not be the best policy from a decision analysis perspective, at least when there are substantial reasons to expect recruitment changes unrelated to stock size. In this case, virtual population analysis and stock reduction analysis models indicate either unusually weak recruitment compensation (steepness h < 0.4) or progressive decline in recruitment carrying capacity, possibly caused by decreases in estuarine rearing habitat associated with declining flows of the Tigris and Euphrates Rivers.  相似文献   

16.
In some fisheries, claims have been made that quota programs have led to increased vertical integration, with processors controlling quota and fishermen. In the US halibut fishery a quota program was designed specifically to maintain the small-scale vessel nature of the fishery. This paper reports on what changes have been seen in the vertical structure of the halibut fishery and offers some explanation for these changes. Results indicate that the specific rights granted can have significantly different effects on the vertical structure of the industry. In the case of the halibut fishery vertical integration was avoided and market transactions actually increased.  相似文献   

17.
Icelandic fisheries have been managed by individual transferable quotas (ITQs) for a decade but there is still no consensus about the quota issue. Distributional effects of ITQs, in terms of income distribution between owner and crew, and the vulnerability of fisheries communities short of quota, have been in the centre of the debate.The author discusses changes in stakeholder involvement in policy-making, conflicts of interest and legal disputes linked to the ITQ-system. By way of conclusion, some options for resolving conflicts and reaching consensus on the fisheries management issue are discussed.  相似文献   

18.
Some scholars have thought the United Nations Convention on the Law of the Sea would transform marine politics and policy by incorporating social values of equity and justice via the Common Heritage of Mankind and authentic conservation of an essential part of the biosphere, displacing the dominant commodification of the ocean. Likewise, the United Nations Food and Agricultural Organization has claimed that the “productivity paradigm” of growth in fishery catch has been replaced by balanced norms of sustainability. This article tests these claims by asking “What is the ‘generative grammar’, or value-based blueprints, of governance for the World Ocean?” using a quantitative content analysis of all extant State of the World Fisheries and Aquaculture (SOFIA) reports (1995–2016). Not only does the analysis disprove the FAO’s assertions, this research reveals an otherwise invisible, non-codified economistic regime governing the World Ocean that is guided by the norms of sheer volume production, named here simply the “World Ocean Regime.” This partially explains why the marine world is experiencing structural ecological changes, including massive biodiversity loss partly driven by overfishing. The analysis finds that overfishing, ecological life support, moral aesthetic values, social equity, and science are very minor concerns for the World Ocean Regime. Governance is the second-most important set of discourses, but this governance is clearly driven by economic values and norms. The World Ocean Regime has critical implications not only for the sustainability of the World Ocean, but the planetary system that depends on the World Ocean.  相似文献   

19.
Flying fish play a vital role in maintaining the balance of marine ecosystems. In Taiwan, flying fish resources are mainly utilized in three ways. The Tao aboriginal people regard them as an important, and spiritual, source of food and utilize the resource sparingly and cautiously. Conversely, in northern Taiwan, fisheries harvest flying fish roe, which may in the future lead to ecosystem damage. Thirdly, large quantities are caught for promoting seafood to tourists at various events. The latter two utilizations may cause overfishing and scarcity.In 2007, the Taiwanese government began to adjust fisheries management policies for monitoring the utilization of flying fish resources. The current policies protect aboriginal marine culture and employ ‘total allowable catch’ (TAC) as a transitional mechanism in flying fish caviar harvesting. In the future, the government should employ collaborative measures at a regional level, including quota allocation based on scientific evidence, in order to maintain ecosystem balance and ensure the sustainability of fish resources. Activities to promote seafood, and the catching of adult fish on a large scale, must be stringently managed according to the amount of resources available. Finally, the most appropriate and least risky approach, is to designate flying fish spawning grounds as marine protected areas.  相似文献   

20.
The Magnuson–Stevens Act is the United States׳ premier law governing fisheries conservation and management. Congress has revisited the Act multiple times since its inception in 1976—most recently in 1996 with the Sustainable Fisheries Act and in 2006 with the Magnuson Stevens Act—and is currently in the process of reauthorizing the Act. The University of Washington focused the 14th annual Bevan Series on Sustainable Fisheries on issues surrounding reauthorization. The symposium featured a diversity of stakeholders, including fisheries scientists, managers, policy analysts, students, non-governmental organizations, Tribes, and industry. The symposium explored the Act׳s history, means of ending overfishing and ensuring accountability, lessons from U.S. West Coast and North Pacific fisheries, and challenges and solutions to ecosystem-based fisheries management.  相似文献   

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