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1.
This study presents the first comprehensive estimation of discard amounts in the Galician fishing fleet, in order to provide an integral view of this increasing environmental problem at a regional scale. Subsequently, a series of improvement actions relating to discard minimization are suggested with the goal of enhancing the performance of the Galician fishing fleet through discard minimization. Discard estimates were constructed individually for the different Galician fisheries by aggregating primary data obtained from a total of 89 fishing vessels and secondary data for those fleets that were not directly sampled. Results showed that roughly 60,250 t of marine organisms were discarded by the Galician fleet in 2008, representing 16.9% of the total capture. Moreover, an important percentage of these discards were linked mainly to trawling vessels and to a lesser extent, to certain long lining fisheries. Therefore, improved management measures in target stocks should take into account the fact that alternative fishing gears other than trawl nets may reduce the amount of discards for certain species. This estimation may improve the assessment of stocks and help to quantify the damage that discards may have on wild ecosystems.  相似文献   

2.
In the context of the Common Fisheries Policy reform, the need for decreasing discards has been highlighted in discussions on the implementation of a discard ban. While most of the research has focused on the quantification of discards by species and métier, identification and quantification of the causes of discards have received little attention. This study presents the results of on-board surveys conducted in the Southern Bay of Biscay fleets of netters and longliners. A large variability of discards was observed. It is also shown that in these passive gear fisheries the main reasons for discarding put forward by fishermen are, firstly, market-related and, secondly, quality-related; discards related to the application of regulations are minor. The results therefore illustrate that decisions to discard can also occur in highly selective fisheries because of economic constraint and the results also show that a part is discarded alive.  相似文献   

3.
In this paper the discard ban policy within the Portuguese fisheries sector is discussed and the opportunities and impact in the fisheries economy that arise from sales of unwanted fish under the new landing obligation are evaluated. The decadal mean price of fish (€/kg, adjusted for inflation) rose from the 1940s until the 1970s, dropping thereafter. The yearly averaged economic income estimated for discards sales between 1969 and 2009 ranged from 419345€ to 2164379€. Discard ban sales could contribute from 10% to 53% of the total landed value and 9–34% of the total catches (landings + discards). Under a discard ban policy, the fishing sector with the largest economic contribution for total discards sales would be multispecies (54%), followed by trawl (26%) and seine (20%). On average, fishing sales contributed with 0.63% to gross domestic production (GDP) between 1938 and 2009. Discard sales can increase 1.07–1.46 times more than the fish landing contribution to GDP. After 1983 the average landings/imports economic ratio was 0.28:1, which means that fish imports surpassed landings economic value 3.57 fold. The discard ban policy can create economic opportunities in the national context thus helping to revitalize some specific fisheries sectors.  相似文献   

4.
The landing obligation recently adopted by the European Union's (EU) Common Fisheries Policy aims to eradicate discards in EU fisheries. The objective of this paper is to investigate the potential social and economic impacts of the discard ban in European small-scale fisheries (SSF) and the critical factors for its successful implementation. An exhaustive systematic literature review and a stakeholder consultation were carried out in order to (i) collect detailed information about current knowledge on discards in EU SSF and gauge stakeholder perceptions about potential impacts of the discard ban in European SSF, (ii) examine the capacity of the SSF industry to implement the discard ban, and (iii) explore the limits and feasibility of implementing such a measure.The results of this study show that little attention has been given by the scientific community to discards in EU SSF. Indeed, the systematic literature review shows that this problem is relatively unexplored in the EU. In addition, the effectiveness of a discard ban in industrial fisheries is still unclear, mainly because discard data are not systematically collected by fisheries authorities. Stakeholders mostly perceive that the new landing obligation was developed with industrial fisheries in mind and that compliance with the landing obligation in EU SSF will be difficult to achieve without high economic costs, such as those related to the handling and storage of unwanted fish on board.  相似文献   

5.
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   

6.
副渔获物对渔业资源的影响及其减少方法的探讨   总被引：1，自引：0，他引：1  
由于渔具不同的选择性和多鱼种鱼类共栖 ,人们在对目标种类进行捕捞时 ,不可避免地产生副渔获物及其抛弃。由于渔业资源的下降和人们对海洋环境保护意识的加强 ,副渔获物及其抛弃问题日益成为人们关注的焦点。本文对世界范围内的渔业活动所产生的副渔获物进行分析 ,根据副渔获物的种类、被抛弃情况和原因以及对渔业资源的影响 ,提出了减少副渔获物和抛弃的方法。  相似文献   

7.
Surveys are often insufficient to accurately capture the distribution of a species in both space and time. Complementary to the use of research vessel data, platforms of opportunity can be a powerful strategy to monitor species distributions at high temporal and spatial resolution.In this study we use data from commercial fishing vessels, collecting – under the European Union data collection framework – biological data on all species that are caught and subsequently discarded. Using such discard data in combination with a systematic trawl survey, we model the spatial and temporal distribution of juvenile plaice (Pleuronectes platessa) in the central North Sea. There is a clear age-dependent difference between the commercial fishing vessel data and the research vessel data, with age 1 being the dominating age in the survey catches, while age 2 is the dominating age in the discards. The results show how immature plaice, slowly migrate from the nursery areas, westwards into the deeper regions of the North Sea. Also, the results show that during the study period, juvenile plaice gradually moved to deeper waters at an earlier age. Finally we discuss how the framework can be applied to similar opportunistic data to monitor seasonal and inter-annual migration of marine organisms, and to quantify how they may be influenced by biotic and abiotic gradients, such as temperature.  相似文献   

8.
A landing obligation was formally implemented in the European Union (EU) for the first time, as part of the recent reform of the EU Common Fisheries Policy (CFP). Given the reasonable success of the landing obligation in some countries such as the Faroe Islands, Iceland and Norway, this policy is seen as a viable approach to tackle the long-recognized discarding problem in EU waters. However, there has been some debate on whether there is sufficient evidence to support the feasibility of such a measure in the EU-CFP. The EU landing obligation will implicitly include all small-scale fisheries (SSF) provided the species captured are subject to catch limits or minimum sizes (in the case of the Mediterranean). SSF were included irrespective of the fact that the discarding problem in the EU has been historically associated with medium- to large-scale fleets (in particular largely mixed species trawl fisheries). Additionally, past experiences with a discard ban policy are still limited to specific countries and/or specific fisheries. This paper examined the appropriateness and feasibility of the recently implemented EU landing obligation in SSF. The effects in the long-term are unpredictable, but available evidence suggests that in the short to medium-term a landing obligation is likely to bring more negative social, economic and ecological impacts than benefits.  相似文献   

9.
Fishery managers are faced with the challenge of maintaining sustainable fisheries at the lowest possible cost while conforming to international and national obligations. Given that fisheries range from low to high value, there is a real need to understand how to trade ecological and economic risks, and the various costs associated with their management, against the benefits from catch. Key to this is an understanding of (a) the costs corresponding to a given level of acceptable risk, or conversely, (b) the change in risk given a change in cost investment. This paper first defines biological, economic and ecosystem risk at a whole-of-fishery level, and then develops a simple model to quantify the trade-offs between risk, cost and catch. Using as case studies Australia's federally managed fisheries that range from data-rich to data-poor, risk was quantified for target species in terms of both their limit and target reference points (defined as “biological risk” and “economic risk”, respectively), and for ecosystems in terms of overall ecological impact (defined as “ecosystem risk”). A statistical linear model was used to quantify the risk–cost–catch frontier for each of the three forms of risk. The most parsimonious models were statistically significant for each. However, the management and research costs were mostly positively correlated with risk, indicating that these tended to be reactive to risk, as opposed to risk decreasing in response to increased costs. The only model where this was not the case was for the ecosystem risk, which is probably because these risks have only recently been assessed and the management response to these risks across all the fisheries has so far been limited. For target species risks, it was not possible to develop a model for proactive use. However, the method itself has merit and, if the costs were defined to a greater level of resolution, and/or a time-dynamic modelling approach considered, these issues could potentially be addressed.  相似文献   

10.
Fisheries management needs to broaden its perspective to achieve sustainable resource use. Life cycle assessment (LCA) is an ISO standardized method to evaluate the environmental impacts of products using a broad and systematic approach. In this study, the outcome of a management regime promoting species-selective trawling in Swedish Nephrops trawl fisheries was studied using LCA methodology by quantifying the impacts per kilogram of landing using two different fishing methods. Demersal trawling has previously been found to be both energy intensive and destructive in terms of seafloor impact and discards. It is demonstrated that species-selective trawling fulfils management objectives, although with tradeoffs in terms of fuel consumption and associated GHG emissions. To prioritize between impacts, one must be aware of and quantify these potential tradeoffs. LCA could be an important tool for defining sustainable seafood production as it can visualize a broad range of impacts and facilitate integrated, transparent decision making in the seafood industry. It is also concluded that, with current LCA methodology, use of total discarded mass could increasingly be distinguished from potential impact by applying two new concepts: primary production requirements and threatened species affected.  相似文献   

11.
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   

12.
Proponents of catch share-based fisheries have claimed ecological stewardship can result from the assignment of individual catch quotas. This claim is examined by analyzing the distribution of benthic habitat protection measures adopted by quota-owning industry sectors within the exclusive economic zones (EEZs) of the U.S. (Alaska), New Zealand, and high seas seamounts within the Southern Indian Ocean Deepsea Fishers Association (SIODFA) competence area. Results suggest the protection of both benthic ecosystems and essential fish habitat (EFH) are marginal at best when quota owners have primacy in determining the boundaries of bottom trawl closures. The majority of the areas in these three regions that are closed to trawling are too deep to fish, may not contain vulnerable marine ecosystems, and do not have high abundances of commercially important species. “Freezing the footprint” of bottom trawling is not the best method for benthic habitat protection in areas where the fishing industry is actively fishing vulnerable habitats. Analytical methods should be applied to help determine boundaries of future bottom trawl closures rather than allowing the fishing industry to place benthic protection areas (BPAs) in areas where they are not interested in fishing.  相似文献   

13.
The reduction of discards in European fisheries has been identified as a specific objective of the reform of the EU Common Fisheries Policy. To reduce the uncertainty in catch data and the socially unacceptable waste of resources that results from the disposal of catch at sea, a policy to ban discards has been proposed. Discard bans are currently implemented in Alaska, British Columbia, New Zealand, the Faroe Islands, Norway and Iceland. Experience from these countries highlights that a policy of mandatory landings can result in a reduction in discards, but relies upon a high level of surveillance or economic incentives to encourage fishers to land more of their catch. Discard bans will also not result in long term benefits to stocks unless total removals are reduced, through the avoidance of undersized, non-commercial or over quota catch. Experience shows that additional management measures are required to incentivise such a move towards more selective fishing. Success has resulted from the use of area closures and bycatch limits, with potential applications in EU fisheries. However, selective fishing will not be a panacea for the current state of European fisheries; discard bans and accompanying measures must be embedded in a wider management system that constrains fishing mortality to reasonable levels before sustainable exploitation can occur.  相似文献   

14.
There is a need to better understand the linkages between marine ecosystems and the human communities and economies that depend on these systems. Here those linkages are drawn for the California Current on the US West Coast, by combining a fishery ecosystem model (Atlantis) with an economic model (IO-PAC) that traces how changes in seafood landings impact the broader economy. The potential effects of broad fisheries management options are explored, including status quo management, switching effort from trawl to other gears, and spatial management scenarios. Relative to Status Quo, the other scenarios here involved short-term ex-vessel revenue losses, primarily to the bottom trawl fleet. Other fleets, particularly the fixed gear fleet that uses pots and demersal longlines, gained revenue in some scenarios, though spatial closures of Rockfish Conservation Areas reduced revenue to fixed gear fleets. Processor and wholesaler revenue tracked trends in the bottom trawl fleet, which accounted for 58% of total landings by value. Income impacts (employee compensation and earnings of business owners) on the broader economy mirrored the revenue trends. The long-term forecast (15 years) from the Atlantis ecosystem model predicted substantial stock rebuilding and increases in fleet catch. The 15 year projection of Status Quo suggested an additional ∼$27 million in revenue for the fisheries sectors, and an additional $23 million in income and 385 jobs in the broader economy, roughly a 25% increase. Linking the ecological and economic models here has allowed evaluation of fishery management policies using multiple criteria, and comparison of potential economic and conservation trade-offs that stem from management actions.  相似文献   

15.
Like many tropical small-scale fisheries, the French Guiana coastal fishery is characterized by the high fish biodiversity of its ecosystem, the weak selectivity of the fleets exploiting the resources, and the heterogeneity of the vessels in terms of size and fishing techniques. The Rapfish method is used to assess sustainability within 11 fishery systems by means of 27 attributes relating to ecological, economic, social, and technological fields. Overall results indicate an average performance in the weak sustainability range. Comparisons made among the FSs show a gradient of sustainability performance from the western portion of the coast to the eastern portion. Several recommendations are formulated to raise the current “sustainability” status, such as the reduction of discards. This study is used as a complementary tool to the bioeconomic model in order to define a sustainable management plan for the French Guiana coastal fishery.  相似文献   

16.
Multi-species fisheries are complex to manage and the ability to develop an appropriate governance structure is often seriously impeded because trading between sustainability objectives at the species level, economic objectives at the fleet level, and social objectives at the community scale, is complex. Many of these fisheries also tend to have a mix of information, with stock assessments available for some species and almost no information on other species. The fleets themselves comprise fishers from small family enterprises to large vertically integrated businesses. The Queensland trawl fishery in Australia is used as a case study for this kind of fishery. It has the added complexity that a large part of the fishery is within a World Heritage Area, the Great Barrier Reef Marine Park, which is managed by an agency of the Australian Commonwealth Government whereas the fishery itself is managed by the Queensland State Government. A stakeholder elicitation process was used to develop social, governance, economic and ecological objectives, and then weight the relative importance of these. An expert group was used to develop different governance strawmen (or management strategies) and these were assessed by a group of industry stakeholders and experts using multi-criteria decision analysis techniques against the different objectives. One strawman clearly provided the best overall set of outcomes given the multiple objectives, but was not optimal in terms of every objective, demonstrating that even the “best” strawman may be less than perfect.  相似文献   

17.
In a context of growing fishing pressures and recommendations for an ecosystem approach to fisheries, there is a need to monitor changes in fish communities over time. In this study, we analysed data from scientific trawl surveys carried out on the continental shelf off Guinea between 1985 and 2012. We performed factorial analyses and calculated biodiversity indices to characterise the changes in the structure and composition of fish communities that occurred over the 28-year period in this area, particularly given intensive fishing activities. We show that, over the study period, fish communities on the Guinean shelf were structured primarily according to spatial factors, with temporal changes being less pronounced than expected. However, a temporal analysis of biodiversity indices and species dominance showed that the intensification of fishing had significant effects on the general ecological features of the fish assemblages under study. There was a decrease in fish density and in mean trophic level. In addition, there were changes in species dominance, whereby large, slow-growing species with high commercial value were gradually replaced by smaller, fast-growing species of lesser commercial interest. These results from field observations are in line with some conclusions from previous modelling studies in the same geographical area, and provide further support for the hypothesis of a progressive ‘ecosystem effect of fishing’ occurring in Guinean waters.  相似文献   

18.
Neoliberal economic and social policies during the last 65 years have placed a premium on continuous economic growth. Concern among ecological economists and other critics that economic growth results in loss of natural capital and ecosystem services led to introduction of the concept of “uneconomic growth,” defined as “growth of the macro economy that costs us more than it is worth” (Daly and Farley, Ecological economics principles and applications. Washington: Island Press; 2004). This paper proposes the concept of “unjust uneconomic growth” to pinpoint the additional costs of policies that promote uneconomic growth to the neglect of other considerations and uses the case of Newfoundland and Labrador fisheries policies since 1992 to document it. Newfoundland and Labrador fisheries experienced uneconomic growth in the 1980s leading to the collapse of ground fish stocks. The policies enacted since 1993 based on economic growth goals have failed to solve the ecological-social crisis and entailed additional costs to small-scale fisheries.  相似文献   

19.
Solutions to the problem of discarding in fisheries have been debated for decades. Despite this attention, measures to ameliorate discarding have had limited success. Regulators, researchers, and industry continue to struggle with fisheries management and foregone yield in the face of the continued wastage of valuable resources due to discarding.Waste minimization and by-product utilization are powerful imperatives in other sectors that are also reliant on the harvest of natural resources. This paper considers the performance of these sectors in waste minimization and by-product utilization, with the aim of identifying practices and processes that may be applied to ameliorate discarding in fisheries.This paper describes the handling, utilization, and mitigation of discards and waste in the livestock farming, agriculture, mining, and waste management industries, and in particular, in forestry. In terms of biological impact, economic objectives, and management approaches the harvesting of trees has substantial similarities to industrialized fishing. However, the forestry sector has found ways to utilize almost 100% of the natural product harvest by establishing markets and new products. Analogous developments within the fishing industry could substantially improve sustainability through reduced levels of discarding and wastage. Based on the experiences of these sectors it is suggested that evaluations of potential Management Strategies are developed to specifically examine discard mitigation approaches on a broader scale than previously conducted.  相似文献   

20.
Designing ITQ programs for commercial recreational fishing   总被引：1，自引：0，他引：1  
This paper discusses the potential for implementing individual transferable quota (ITQ) schemes in commercial recreational fisheries, focusing particularly on charter and headboat fisheries. After a brief discussion of ITQs in commercial fisheries, the paper discusses the manner in which rents get dissipated in commercial recreational fisheries. Fishing mortality in recreational fisheries is determined as a joint outcome of angler behavior and trip supply. In the recreational sector under open access conditions, there are likely to be too many vessels providing too many trips at prices that are too low. Vessel input configurations are likely to be distorted in a manner that generates excessive fishing mortality. Designing ITQs for recreational fisheries requires consideration of issues not prominent in the design of commercial fisheries. Among the most important is the manner in which angler preferences and types affect overall mortality from both landings and discards. While catch and release fisheries and pure food fish recreational fisheries are relatively easy to manage with recreational ITQs, fisheries with both angler types present difficult monitoring problems that add complexities to ITQ design. Various ways to design programs that account for both landings and discard mortalities and that generate incentives for anglers and vessel owners to reduce discard mortality are discussed.  相似文献   

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