首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
This paper examines the sustainability of United States fisheries managed under the Magnuson-Stevens Fishery Conservation and Management Act, the law that provides the framework for federal fisheries management. Sustainability across a broad suite of criteria, including health of the fished stock, bycatch, and effects on the habitat and ecosystem, was measured against the Monterey Bay Aquarium׳s Seafood Watch criteria for ecological sustainability. Seafood Watch ratings and numerical scores for U.S. federally managed fisheries were analyzed to elucidate strengths and weaknesses among federally-managed fisheries. Of U.S. federally managed fisheries assessed by Seafood Watch, only 2% are rated “Avoid”, and strong ratings for stock health for nearly all fisheries indicate that the Magnuson-Stevens Act is fundamentally succeeding at maintaining or rebuilding the abundance of targeted stocks. The majority (79%) of U.S. fisheries earn the intermediate rating of “Good Alternative”, and 19% earn the top rating of “Best Choice”. Given that U.S. fisheries management is considered among the strongest in the world, this analysis assesses why the majority of U.S. fisheries are not rated “Best Choice”. Fisheries for all variety of species, and using a wide range of fishing methods, can merit “Best Choice” status. However, the majority of U.S. fisheries do not achieve this rating due primarily to bycatch concerns. By improving performance with regard to bycatch, most “Good Alternative” U.S. federal fisheries could reach “Best Choice” status and reap rewards in the marketplace for that recognition. Findings suggest that current science-based management should be maintained in the Magnuson-Stevens Act reauthorization, managers should adopt best practices based on fisheries that are already performing well in the U.S., and more specific federal bycatch mitigation requirements should be implemented.  相似文献   

2.
Fisheries learning exchanges (FLE) can be useful for enhancing fisheries management. Reversing the decline of the North Pacific loggerhead turtle is a priority articulated in US, Japanese, and Mexican natural resources policy. However, by 2005, while nesting beach protection was strong in Japan and bycatch reduction had been achieved in U.S. Hawaii-based longline fisheries, bycatch mortality was very high in Mexican artisanal fisheries and believed to be problematic in Japanese coastal fisheries. Efforts to conserve the population were hindered by lack of understanding and cooperation by and between fishers, conservation practitioners, scientists, and managers of all three countries. The authors produced a trinational FLE with participants from Japan, Mexico, and Hawaii to share bycatch challenges and develop solutions. The trinational FLE gave fishers and other participants new, otherwise unattainable knowledge, perspectives, and experiences that empowered them as leaders among their peers, resulting in unexpectedly strong cultural and conservation outcomes that included: a) understanding of the myriad threats to loggerheads throughout their ranges and lifetimes, b) development of a transpacific conservation partnerships to undertake coordinated recovery efforts, c) participatory research to develop and test bycatch reduction technological and practical solutions for Japan and Mexico, and d) hundreds of juvenile loggerheads spared per yr from bycatch mortality via changes in fishing practices by FLE participants. The authors conclude that the reciprocal FLE can serve as a practical tool with potential for broad application for empowering fishers and other fisheries stakeholders to improve fisheries.  相似文献   

3.
In Pacific Mexico, all five sea turtle species have declined over the past century due to intense overexploitation of meat and eggs, fisheries bycatch, and degradation of marine and nesting habitats. One of the most heavily impacted areas has been the Baja California peninsula, where sea turtle populations remain historically low despite existing conservation measures that include a complete moratorium on the use of sea turtles, over three decades of widespread protection of nesting beaches, and in-water monitoring of sea turtles at coastal foraging areas. We recognize the need for alternative sea turtle conservation strategies that rely on increased participation of civil society and Mexican citizens. The purpose of this paper was to identify resident attitudes towards sea turtle conservation and opportunities for enhanced community participation in Bahia Magdalena, a region in Baja California Sur, Mexico experiencing high levels of sea turtle poaching and bycatch in fisheries. Through semi-structured interviews we found that while residents were overwhelmingly interested in participating in sea turtle conservation, peer pressure and conflict within the community presented major challenges. The majority of residents indicated that sea turtle voluntourism would have a positive impact on their community. Economic incentives and increased protection for sea turtles were mentioned as benefits of sea turtle voluntourism, whereas peer pressure, difficulty obtaining permits and producing effective marketing materials, and doubt about direct economic benefits were cited as constraints. We discuss our results in terms of opportunities, challenges, and recommendations for improving community-focused sea turtle conservation throughout the region.  相似文献   

4.
This paper reviews the available information (observer programs, estimates, statutes, regulations) for bycatch of marine mammals, sea turtles, and seabirds in fisheries of the United States. Goals of the review were to evaluate the state of knowledge of bycatch and the role of existing protective legislation in shaping bycatch management for different taxa. Pressing issues are identified, as well as knowledge gaps and policy limitations that hinder multi-species bycatch reduction. The USA has made important progress toward reducing bycatch in its fisheries, but the efficacy of its management has been limited somewhat by a focus on taxon- and fishery-specific regulation and the lack of consistent mandate across taxa for taking a cumulative perspective on bycatch. Applying consistent criteria across taxa for setting bycatch limits (e.g., extending the approach used for marine mammals to sea turtles and seabirds) would be the first step in a multi-species approach to bycatch reduction. A population-based multi-species multi-gear approach to bycatch would help identify priority areas where resources are needed most and can be used most effectively.  相似文献   

5.
The purpose of this short communication is to describe the Third International Workshop on Sea Turtle Conservation and Fisheries Exchange that took place from April 22–30, 2009 on Cuba’s Isla de la Juventud [Isle of Youth]. A group of 28 fishers, conservationists, marine scientists and fisheries managers from Cuba, Mexico and the U.S. gathered at Siguanea Bay off the island’s southwest coast. The goals of the exchange were to 1) provide a forum for sea turtle experts and fishing communities in Cuba, Mexico, and the U.S. to share experiences on conservation activities, 2) develop the scientific basis for future conservation in this highly biologically important region of Cuba, and 3) increase support by Cuban fishers for local sea turtle conservation efforts. During the exchange, participants met with local Cuban fishers about the challenges of conserving sea turtle populations while maintaining their fishing livelihoods, shared solutions developed by fishers to accomplish the same in Mexico, and undertook field and cultural activities. Key outcomes for the exchange include an improved understanding of sea turtle bycatch off the Isla de la Juventud, enhanced collaboration among the three nations in turtle conservation, and increased motivation by fishers to participate in sea turtle research and conservation. Additionally, as a direct result of this exchange, the community of Cocodrilo on the Isla de la Juventud has hosted annual sea turtle festivals that increase support for turtle conservation efforts by the local community.  相似文献   

6.
Mitigating the environmental impact of commercial fishing, by avoiding, minimizing and compensating for adverse effects, is core business for fisheries management authorities globally. The complex interplay of ecological, economic, and social considerations has often resulted in bycatch management being reactive, confrontational and costly. In many cases it has been difficult to demonstrate success and to establish whether bycatch management has been efficient or effective. This article proposes standards for bycatch management following reviews of literature, international agreements and Australian domestic fishery management policies, and consideration by many technical experts and several stakeholder representatives. The standards have been developed using Australian Commonwealth fisheries – and the international fisheries agreements to which Australia is party – as a baseline, but should be applicable to both domestic and regional/international governance systems. The proposed standards involve quantifying fisheries bycatch, agreeing on operational objectives, assessing the effects of fishing on bycatch populations, establishing the cost-effectiveness of mitigation measures, and evaluating performance. The standards encourage domestic management measures that are consistent with the guidance and requirements of international agreements and regional fisheries management organisations. The importance of engaging stakeholders throughout the process is recognised. The standards provide a framework for measuring performance and a checklist of actions for managing bycatch at a fishery level. They have the potential to facilitate the development of more strategic and effective approaches to bycatch management, with defined goals, monitoring systems, and adaptive decision-making. This review of past bycatch management, including the application of the proposed standards to the mitigation of shark bycatch in an Australian longline fishery, demonstrates that the proposed standards are operationally feasible but that they have not always been applied. Specifically, monitoring the performance of bycatch management measures has not always followed their implementation.  相似文献   

7.
Unselective fishing catches non-target organisms as ‘bycatch’—an issue of critical ocean conservation and resource management concern. However, the situation is confused because perceptions of target and non-target catch vary widely, impeding efforts to estimate bycatch globally. To remedy this, the term needs to be redefined as a consistent definition that establishes what should be considered bycatch. A new definition is put forward as: ‘bycatch is catch that is either unused or unmanaged’. Applying this definition to global marine fisheries data conservatively indicates that bycatch represents 40.4 percent of global marine catches, exposing systemic gaps in fisheries policy and management.  相似文献   

8.
Bycatch reduction technologies (BRTs) have been developed to limit the incidental capture of non-target marine species in fishing gear, especially those species of special concern. However, in the absence of enforcement, the proven effectiveness of a BRT alone does not guarantee its adoption by fishermen. Human factors also play a fundamental role. This case study was directed at evaluating the willingness of Sicilian longline fishermen to use relatively large circle hooks (size 16/0) as a BRT for the loggerhead sea turtle Caretta caretta. Fishermen were involved in testing circle hooks with their fishing vessels and their own commercial fishing gear, and their opinions before and after trials at sea were recorded. The present study showed the importance of creating a positive human context for testing a BRT. Findings provided additional confirmation about the usefulness of relatively large circle hooks to reduce the bycatch of loggerhead sea turtles on drifting longlines. Interviews before and after trials at sea indicated that socio-economic and emotional factors are essential for successful uptake of BRTs. Crews of large fishing vessels stated that they would be willing to use circle hooks in months with a high probability of turtle captures (June-September) if an economic incentive was provided and there was also public acknowledgement of their efforts. The fishermen's cooperatives association involved in the project is currently evaluating the creation of a product label identifying the harbors where fishing was performed using circle hooks.  相似文献   

9.
This paper explores conservation policy pertinent to three species of marine turtles affected by fisheries, while crossing jurisdictions in their seasonal migrations through the SW Atlantic, particularly the Argentine waters. This case study reviews local legal and institutional frameworks for Argentina and concludes that tools are in place to monitor and mitigate the negative impact of bycatch on the populations. Argentina is signatory of the most relevant international treaties aimed at protecting transboundary species (e.g. Inter-American Convention for the Protection and Conservation of Sea Turtles, Convention on the Conservation of Migratory Species of Wild Animals). Legislation also exists at the federal and provincial levels. Yet, accidental captures continue to occur due to weaknesses in enforcement and the low priority that conservation has in fisheries management decisions. Some urgent practical actions supported by policy are suggested: (a) placement of on-board observers in coastal fishing fleets, (b) application of existing mitigation measures to reduce bycatch, (c) design of a national plan of action for marine turtles in Argentina, and (d) development of a regional plan between Argentina, Brazil and Uruguay. Stakeholder involvement, especially the fishing sector but also the civil society, would be important to energize practical and effective conservation decisions. The example of Argentina is typical for the region and may apply to other countries as well. The conservation community requires investing more in the application of policy, concomitant with perfecting legal tools.  相似文献   

10.
Fleet communication systems report near real-time observations of bycatch hotspots to enable a fishery to operate as a coordinated “One Fleet” to substantially reduce fleet-wide capture of protected bycatch species. This benefits the bycatch species per se, reduces waste, and can provide economic benefits to industry by reducing risk of exceeding bycatch thresholds and causing future declines in target species catch levels. We describe case studies of fleet communication programs of the US North Atlantic longline swordfish fishery, US North Pacific and Alaska trawl fisheries, and US Alaska demersal longline fisheries, and identify alternative fleet communication program designs to reduce fisheries bycatch. Evidence supports the inference that these three fleet communication programs substantially reduced fisheries bycatch and provided economic benefits that greatly outweighed operational costs. Fleet communication may be appropriate in fisheries where there are strong economic incentives to reduce bycatch, interactions with bycatch species are rare events, adequate onboard observer coverage exists, and for large fleets, vessels are represented by a fishery association.  相似文献   

11.
Emerging fisheries and changes in fishery practices are not always readily apparent, nor are their impacts on non-target species such as seabirds, sea turtles, and marine mammals. Data from several different sources led managers to discover high rates of sea turtle bycatch in an inshore large-mesh gillnet fishery in North Carolina, USA, particularly the emerging deep-water gillnet fishery. This paper reviews the history of how increased numbers of observed stranded sea turtles in 1999 led to the discovery that turtles were becoming entangled in the large-mesh gillnet fishery in Pamlico Sound, North Carolina. It also demonstrates how a variety of data sets from fisheries observers, aerial surveys, and fisheries statistics programs contributed to shaping management of the large-mesh gillnet fishery in Pamlico Sound to decrease turtle bycatch and now point towards the need of additional assessment of gillnet bycatch in other parts of North Carolina. Finally, potential approaches are discussed for a more timely detection of future fishery conflicts and development of a plan to reduce otherwise inevitable bycatch and disruptions to fishing effort.  相似文献   

12.
Sea turtles can be incidentally caught in pelagic longline fishing gear targeting tuna and swordfish. Bycatch to fish catch (B/C) ratios can differentiate seafood based on sea turtle impacts. This study demonstrates the use of B/C ratios indexed to the weight of fish catch: (1) to report on the significant progress in reducing sea turtle bycatch in Hawaii's swordfish longline sector and (2) to compare Hawaii and other Pacific longline fisheries by number of sea turtle interactions per weight of catch. Hawaii's longline tuna fishery sets the benchmark of 1 sea turtle interaction per 190,000 kg of tuna caught.  相似文献   

13.
Many authors have suggested the use of a cap and trade auction system to help reduce bycatch—the incidental take of species by fishing gear targeting other species—of sea turtles in the Hawaii-based swordfish longline fishery. However, we know of no quantitative evaluations of the method. We present a simple mathematical model to serve as a framework to evaluate bycatch auction systems quantitatively. We conclude that cap and trade auction systems have the potential to reduce sea turtle bycatch by creating a financial incentive, while keeping permit costs down to 2–3% of total revenues. While stringent regulations aimed at conserving endangered sea turtles would still be essential, implementation of an auction for issuing transferable bycatch permits would likely enhance the economic efficiency of the fleet. Sea turtle mortality could be reduced further if a shrinking cap on total turtle mortality was introduced, taking advantage of the incentives for reducing turtle mortality that are introduced by the cap and trade auction system.  相似文献   

14.
Despite a powerful, federal legislative framework established to protect threatened and endangered species in the United States, conservation actions can be hindered by the complexity of the full management structure. This is particularly true when state and federal agencies share the responsibility to conserve endangered species. To illustrate this point, this paper describes the management of sea turtle by-catch in commercial fisheries within the state waters of North Carolina. It reviews past and present by-catches, summarizes state and federal efforts intended to reduce sea turtle by-catch, and discusses the challenges posed by the involvement of multiple agencies with conflicting objectives. It concludes by recommending fundamental changes to this management framework and, in particular, proposes the establishment of a multilayered stakeholder group that would work to reduce sea turtle by-catch while supporting vibrant commercial fisheries in the state.  相似文献   

15.
Overexploitation of bycatch and target species in marine capture fisheries is the most widespread and direct driver of change and loss of global marine biodiversity. Bycatch in purse seine and pelagic longline tuna fisheries, the two primary gear types for catching tunas, is a primary mortality source of some populations of seabirds, sea turtles, marine mammals and sharks. Bycatch of juvenile tunas and unmarketable species and sizes of other fish in purse seine fisheries, and juvenile swordfish in longline fisheries, contributes to the overexploitation of some stocks, and is an allocation issue. There has been substantial progress in identifying gear technology solutions to seabird and sea turtle bycatch on longlines and to direct dolphin mortality in purse seines. Given sufficient investment, gear technology solutions are probably feasible for the remaining bycatch problems. More comprehensive consideration across species groups is needed to identify conflicts as well as mutual benefits from mitigation methods. Fishery-specific bycatch assessments are necessary to determine the efficacy, economic viability, practicality and safety of alternative mitigation methods. While support for gear technology research and development has generally been strong, political will to achieve broad uptake of best practices has been lacking. The five Regional Fisheries Management Organizations have achieved mixed progress mitigating bycatch. Large gaps remain in both knowledge of ecological risks and governance of bycatch. Most binding conservation and management measures fall short of gear technology best practice. A lack of performance standards, in combination with an inadequate observer coverage for all but large Pacific purse seiners, and incomplete data collection, hinders assessing measures' efficacy. Compliance is probably low due to inadequate surveillance and enforcement. Illegal, unreported and unregulated tuna fishing hampers governance efforts. Replacing consensus-based decision-making and eliminating opt-out provisions would help. Instituting rights-based management measures could elicit improved bycatch mitigation practices. While gradual improvements in an international governance of bycatch can be expected, market-based mechanisms, including retailers and their suppliers working with fisheries to gradually improve practices and governance, promise to be expeditious and effective.  相似文献   

16.
Bycatch presents a challenge to optimizing yield in commercial fisheries, where bycatch can total more than 1 million mt per year in the United States. Yet the economic impacts of bycatch have rarely been evaluated in the scientific literature. These economic impacts largely occur from the loss of landings through (1) early closure of fisheries when catch limits of bycatch species are reached; and (2) discards of marketable catch due to regulatory requirements in the fishery. This paper illustrates the economic impacts of early closures due to bycatch in U.S. fisheries by describing past case studies, as well as evaluating the economic impacts of discarding fish in U.S. commercial fisheries. Premature closures in the fisheries reviewed resulted in potential losses ranging from $34.4 million to $453.0 million annually. Nationally, bycatch estimates in the form of regulatory discards are annually reducing the potential yield of fisheries by $427.0 million in ex-vessel revenues, and as much as $4.2 billion in seafood-related sales, $1.5 billion in income, and 64,000 jobs. Our review also shows that some of the most promising work to reduce bycatch over the last decade has been the development of gears or gear modifications, termed “conservation engineering.”  相似文献   

17.
The catch of non-target species or discarding of target species (bycatch) in commercial fisheries can result in negative species level and ecosystem wide impacts as well as adverse social and economic effects. Bycatch has become one of the foremost, global issues of fishery managers and conservationists, especially when the non-target species is from a protected or threatened population. However, the impact and spatial distribution of bycatch is frequently unknown making it difficult to develop effective, justifiable mitigation regulations. This challenge is exemplified by the bycatch of river herring (alewife, Alosa pseudoharengus, and blueback herring, A. aestivalis) and American shad (A. sapidissima) in the northwest Atlantic mid-water trawl fishery targeting Atlantic herring (Clupea harengus) and Atlantic mackerel (Scomber scombrus). As an alternative to immediate management action, a voluntary bycatch avoidance program was established through an industry, state government, and university partnership. Here the program is described and its impact is evaluated by comparing fleet behavior and bycatch prior to and during the program. The combined results suggest that consistent communication, facilitated by the avoidance program, positively influenced fishing habits and played a role in the approximately 60% decrease in total bycatch and 20% decrease in the bycatch ratio observed during the program. However, the success of small scale move-along strategies to reduce bycatch ratios varied greatly in different areas of the fishery and years. This suggests the program is best viewed as an intermediate or complimentary solution. Overall, this project exemplifies of how collaborative programs can help alleviate difficult management scenarios.  相似文献   

18.
In the Northeast Atlantic, elasmobranchs are a common bycatch in many fisheries, including demersal trawls, longlines, or gillnets and many countries do not have regulations or any control over the amount taken. In the Mid Atlantic, the Azores EEZ (Exclusive Economic Zone), small-scale fishing operations, artisanal and hook-and-line fishing methods are responsible for part of local total landed elasmobranch biomass, although some species are specifically focused and severely harvested by international large-scale fleets. This work provides a review and analysis of the commercial elasmobranch fisheries in the Azores EEZ, and its evolution over the last two decades, highlighting management priorities, taking into account the Northeast Atlantic elasmobranch fisheries status. In the Mid-Atlantic, elasmobranch fisheries mainly target 4 species, that are usually landed as bycatch: the tope shark (Galeorhinus galeus) and the thornback ray (Raja clavata), captured mainly by local demersal artisanal fisheries, the blue shark (Prionace glauca) and the shortfin mako shark (Isurus oxyrinchus) captured by a more industrialised fleet, including those from foreign nations. Considering elasmobranchs life history traits and fishery history, caution is advised in the development of a management strategy focusing on these species, considering the Northeast Atlantic context and regional, local and national interests.  相似文献   

19.
Fatal entanglements in fishing gear threaten marine mammal populations worldwide. The management of entanglements of large whales, such as the North Atlantic right whale (Eubalaena glacialis), with commercial fisheries, is a challenge given the species’ small population size, economic consequences of regulations, and the general lack of data on entanglements. The U.S. Marine Mammal Protection Act (MMPA) requires development of programs to limit marine mammal entanglement in commercial fishing gear. Following a retrospective look at implementing aspects of the MMPA, a set of guiding principles were developed with associated best practices useful in reducing fatal large whale entanglement in fishing gear. Among these are: 1) involve stakeholders early in the decision making process; 2) establish a transparent management strategy that includes critical needs to guide research; 3) use a variety of tools such as an established process for receiving new information and ideas; and 4) incorporate adaptive management which considers the constraints of dynamic (rapid) changes to some fixed fishing gear. Efforts to reduce worldwide marine mammal bycatch will typically occur in a data-limited environment as experienced with U.S. Atlantic large whale entanglements. The guiding principles will remain as key tools for reducing large whale bycatch in fisheries as they build upon common practices. These insights developed over two decades of management can potentially help others to address similar bycatch problems.  相似文献   

20.
The South African midwater trawl fishery targets adult horse mackerel Trachurus capensis. The bulk of the catch is taken by a single freezer-trawler, the biggest fishing vessel operating in South African waters. As fishing takes place off the south coast in ecologically sensitive areas, there are concerns about the potential impacts of this fishing operation on non-target species. Fishing behaviour and bycatch of this fishery from 2004 to 2014 were investigated by analysing observer records with regard to catch composition, volume and temporal and spatial patterns. The midwater trawl fishery was estimated to have caught 25 415 tonnes annually, with a bycatch of 6.9% of the total catch, by weight. There are species overlaps with various fisheries, namely the demersal trawl, small-pelagic, line, shark longline and squid fisheries, yet the total bycatch estimates from this fishery are generally small relative to catches taken in the target fisheries. Bycatch species with the highest average annual catches were chub mackerel Scomber japonicus, redeye roundherring Etrumeus whiteheadi, ribbonfish Lepidopus caudatus and hake Merluccius spp. Large-fauna bycatch species included sunfish Mola mola as well as a number of CITES II- and IUCN-listed species, such as Cape fur seal Arctocephalus pusillus, dusky shark Carcharhinus obscurus, smooth hammerhead shark Sphyrna zygaena and thresher sharks Alopias spp. The 97.9% observer coverage is high and the 6.9% bycatch rate low compared to other South African fisheries; however, due to the large size of the individual hauls (average of 46.3 t), the average sampling rate of 1.56% is low. Our analyses suggest that bycatch in the South African midwater trawl fishery has been lower than in other South African fisheries and similar fisheries elsewhere, but due to the combination of high catch volumes and low sampling rates, estimation errors for rare species are high and there is a substantial risk of incidental unmonitored bycatch of rare large fauna and aggregations of small fauna. This could be mitigated by spatio-temporal management of this fishery, to avoid fishing in high-risk areas, and the introduction of an electronic monitoring programme.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号