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1.
The establishment of no‐take marine reserves has been increasingly promoted as a key measure to achieve conservation and sustainability goals in fisheries. Regardless of the wide range of benefits cited, the effectiveness of reserve establishment depends critically on fisheries management outside the reserves. We construct a bioeconomic model of a fishery that allows for the establishment of a no‐take marine reserve and evaluate how the choice of the off‐reserve management target influences the effectiveness of reserve establishment. We evaluate two biomass targets: (i) BMSY or the biomass that produces the maximum sustainable yield (MSY) and (ii) BMEY or the biomass that maximizes the net present value of the returns to fishing. The parameterized model shows that, for a wide range of scenarios, the fishery will be better off in terms of both conservation and economic objectives when the no‐take reserve is established in conjunction with the BMEY target rather than with the BMSY target. Model results further show that the opportunity cost of securing additional fish biomass, in both deterministic and stochastic environments, is lower when the reserve size is increased under the BMEY target. This finding is important because marine reserves have been established as a key measure to restore depleted fish stocks, and the results suggest that this objective can be achieved with lower economic costs in a BMEY managed fishery. 相似文献
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Marine reserves are considered to be a central tool for marine ecosystem‐based management in tropical inshore fisheries. The arguments supporting marine reserves are often based on both the nonmarket values of ecological amenities marine reserves provide and the pragmatic cost‐saving advantages relating to reserve monitoring and enforcement. Marine reserves are, however, only one of a suite of possible policy options that might be used to achieve conservation and fisheries management objectives, and have rarely been the focus of rigorous policy analyses that consider a full range of economic costs and benefits, including the transaction costs of management. If credible analyses are not undertaken, there is a danger that current enthusiasm for marine reserves may wane as economic performance fails to meet presumed potential. Fully accounting for the value of ecological services flowing from marine reserves requires consideration of increased size and abundance of focal species within reserve boundaries, emigration of target species from reserves to adjacent fishing grounds, changes in ecological resilience, and behavioural responses of fishers to spatially explicit closures. Expanding policy assessments beyond standard cost–benefit analysis (CBA) also requires considering the impact of social capital on the costs of managing fisheries. In the short term, the amount of social capital that communities possess and the capacity of the state to support the rights of individuals and communities will affect the relative efficiency of marine reserves. Reserves may be the most efficient policy option when both community and state capacity is high, but may not be when one and/or the other is weak. In the longer term, the level of social capital that a society possesses and the level of uncertainty in ecological and social systems will also impact the appropriate level of devolution or decentralization of fisheries governance. Determining the proper balance of the state and the community in tropical fisheries governance will require broad comparative studies of marine reserves and alternative policy tools. 相似文献
3.
Yimin Ye Kevern Cochrane Gabriella Bianchi Rolf Willmann Jacek Majkowski Merete Tandstad Fabio Carocci 《Fish and Fisheries》2013,14(2):174-185
Many of the world’s fish stocks are depleted as a result of overexploitation, pollution and habitat loss. The 2002 World Summit on Sustainable Development (WSSD) sets a target for fisheries to maintain or restore stocks to levels that can produce the maximum sustainable yield (MSY) by 2015. We assessed the global stock status and found that 68% were at or above the MSY level in 2008 and that the 2015 target is unlikely to be met. We compiled data for eight indicators to evaluate the sustainability of fisheries and the gap to meet the WSSD target. These indicators show that the overall condition of global fisheries is declining, long‐term benefits are being compromised, and pressures on fisheries are increasing despite fisheries policy and management actions being taken by coastal States. We develop a bio‐economic model to estimate the costs and benefits of restoring overfished stocks. Our results show that the global fishing capacity needs to be cut by 36–43% from the 2008 level, resulting in the loss of employment of 12–15 million fishers and costing US$96–358 billion for buybacks. On the other hand, meeting the WSSD goal will increase annual fishery production by 16.5 million tonnes, annual rent by US$32 billion and improve biodiversity and functioning of marine ecosystems. However, progress towards rebuilding has been hindered by an unwillingness or inability to accept the short‐term socio‐economic consequences associated with rebuilding fisheries. Thus, there is a pressing need for integration of rebuilding plans into national political and economic decision‐making. 相似文献
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- 1. Marine reserves can play an important role in the conservation of subpopulations of marine fish metapopulations. The population spatial structure of northern Atlantic cod of Newfoundland and Labrador has characteristics of a metapopulation. Subpopulations of northern Atlantic cod on the continental shelf were decimated by decades of overfishing, and have not recovered. The remaining northern cod are concentrated in coastal areas.
- 2. A Marine Protected Area (MPA) was established in Gilbert Bay, Labrador by the Government of Canada in 2005 to protect the bay's resident subpopulation of northern Atlantic cod. Conservation of Gilbert Bay cod will help protect the genetic diversity of the northern cod metapopulation.
- 3. Unlike some other MPAs, Gilbert Bay is not a harvest refugium or ‘no‐take’ reserve. Aboriginal subsistence fisheries for salmonids with a bycatch of cod are allowed in designated areas of the MPA. A recreational fishery for Atlantic cod by angling open to all people is under consideration. Management of the MPA must ensure that fishing activities do not endanger the local cod population.
- 4. The population dynamics of Gilbert Bay cod were simulated using an age‐structured Leslie matrix model to estimate the total mortality under various recreational fishing scenarios. The level of sustainable harvest by a recreational fishery depends on the natural mortality of the Gilbert Bay cod population, which is unknown. Therefore, there is risk in permitting a recreational fishery in the MPA.
- 5. There may be benefits to the northern cod metapopulation, if the Gilbert Bay subpopulation is allowed to rebuild to the carrying capacity of the bay. If the abundance of Gilbert Bay cod exceeds the level which the local marine ecosystem can support, some cod may emigrate from the bay and recolonize adjacent coastal areas. The potential for Gilbert Bay cod to recolonize continental shelf areas is less certain.
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No‐take marine reserves are increasingly popular tools for conservation and fisheries management. While much attention has been paid to evaluating the effects of design aspects (size, location, etc.) in achieving reserve objectives, less emphasis has been placed on the role of stakeholder compliance. Therefore, the first aim of this study was to evaluate the state of compliance literature and examine the methods used to measure compliance in reserves. The state of compliance literature is limited, although publications with compliance information have increased sixfold in the last decade. However, most studies containing compliance information (63%) fail to provide quantitative estimates. Furthermore, most (95%) quantitative estimates of compliance were reported using a single method, which is problematic because each method has biases and limited applicability. Methods used to indicate compliance include (i) direct observation; (ii) indirect observation; (iii) law enforcement records; (iv) direct questioning; (v) expert opinion; and (vi) modelling. Our second aim was to empirically demonstrate the critical role of compliance in reserve outcomes by comparing a mixed‐effects model on compliance data synthesized from 63 marine reserves to that of a null model. The model of best fit demonstrated a negative relationship between non‐compliance and target species biomass response ratios. Thus, without incorporating any aspects of reserve design, compliance data predicted reserve response ratios of fish biomass. Accordingly, researchers should explore ways to better understand and measure non‐compliance. Therefore, future research should triangulate multiple sources of quantitative compliance data collected using standardized techniques and conduct baseline surveys before reserve implementation. 相似文献
9.
Contemporary and emerging fisheries in The Bahamas—Conservation and management challenges,achievements and future directions 
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下载免费PDF全文 Krista D. Sherman Aaron D. Shultz Craig P. Dahlgren Claire Thomas Edward Brooks Annabelle Brooks Daniel R. Brumbaugh Lester Gittens Karen J. Murchie 《Fisheries Management and Ecology》2018,25(5):319-331
The harvest of marine resources has long‐standing cultural and economic importance to The Bahamas and other small island developing states. Tourists and residents place a demand on local marine resources, particularly Caribbean spiny lobster, Panulirus argus (Latreille), queen conch, Lobatus gigas (Linnaeus) and Nassau grouper, Epinephelus striatus (Bloch), and many fishery products are also sold on the global market. Illegal, unreported and unregulated fishing coupled with inadequate regulations and enforcement are the main factors contributing to the decline of Bahamian fisheries along with other anthropogenic impacts. This article reviews the status of fisheries management in The Bahamas using economically and ecologically important species as case studies to highlight conservation successes, knowledge gaps and deficiencies in existing management approaches. The review concludes with an examination of how emerging fisheries and improved conservation management strategies have the potential to improve economic and food security throughout the archipelago. 相似文献
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Mary E Hunsicker Timothy E Essington Reg Watson Ussif R Sumaila 《Fish and Fisheries》2010,11(4):421-438
Cephalopods are a key component of marine food webs, providing sustenance for myriad marine species. Cephalopods are also of increasing economic importance as evidenced by the rapid rise in their global landings over recent decades. If fisheries continue on this trajectory, conflicts may transpire among cephalopod and finfish fisheries, particularly in ecosystems where cephalopods are highly valuable both directly as a landed commodity and indirectly as prey for other harvested species. We provide the first measure of the ecosystem services that cephalopods contribute to fisheries in 28 marine ecosystems, both as a commodity and an ecological support service. We also evaluate how current demands on cephalopods compare to mid‐20th century conditions. We find that cephalopod contributions to fisheries vary widely, but are substantial in many ecosystems. Commodity and supportive services provided by cephalopods contributed as much as 55% of fishery landings (tonnes) and 70% of landed values ($USD). The contribution of cephalopods as a commodity was generally greatest in the coastal ecosystems, whereas their contribution as a supportive service was highest in open ocean systems. Further, the commodity and supportive services provided by cephalopods to fisheries landings increased in most of the coastal ecosystems between the mid‐20th century (years 1960–70) and contemporary periods (years 1990–2004), indicating the rising demand for cephalopods. Current demands have no historical precedent and ecosystems in which cephalopods are highly exploited as a targeted resource and as an ecological support service should be further evaluated to prevent the unsustainable development of marine fisheries within them. 相似文献
11.
Linking coastal aquaculture of meagre Argyrosomus regius and Western Mediterranean coastal fisheries through escapes incidents 下载免费PDF全文
下载免费PDF全文 P. Arechavala‐Lopez J. M. Valero‐Rodriguez J. Peñalver‐García D. Izquierdo‐Gomez P. Sanchez‐Jerez 《Fisheries Management and Ecology》2015,22(4):317-325
Escape incidents in coastal aquaculture lead to economic losses for farmers and may have indirect socio‐economic effects on local fisheries. In this study, the relationship of meagre, Argyrosomus regius (Asso), production in open‐sea cages and coastal small‐scale fisheries was analysed through captures of escapes, which are easily detected because this species is considered locally absent in native communities in Western Mediterranean regions. Scale reading showed that 100% of captured meagre were escapees. The existence of a direct relationship, in terms of biomass, between the development of meagre coastal aquaculture and the increase of captures of this species by local fisheries was demonstrated. The spatial distribution of meagre captures suggested that there is a local environmental and economic interaction between meagre aquaculture and fisheries through escapees. Monitoring the presence of locally absent species such as meagre within landings might help to assess the magnitude of escapes, the potential economic effects on local aquaculture and fishery industries, and the potential adverse ecological impacts on local ecosystems. 相似文献
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William W L Cheung Miranda C Jones Vicky W Y Lam Dana D Miller Yoshitaka Ota Louise Teh Ussif R Sumaila 《Fish and Fisheries》2017,18(2):254-263
Climate change is projected to redistribute fisheries resources, resulting in tropical regions suffering decreases in seafood production. While sustainably managing marine ecosystems contributes to building climate resilience, these solutions require transformation of ocean governance. Recent studies and international initiatives suggest that conserving high seas biodiversity and fish stocks will have ecological and economic benefits; however, implications for seafood security under climate change have not been examined. Here, we apply global‐scale mechanistic species distribution models to 30 major straddling fish stocks to show that transforming high seas fisheries governance could increase resilience to climate change impacts. By closing the high seas to fishing or cooperatively managing its fisheries, we project that catches in exclusive economic zones (EEZs) would likely increase by around 10% by 2050 relative to 2000 under climate change (representative concentration pathway 4.5 and 8.5), compensating for the expected losses (around ?6%) from ‘business‐as‐usual’. Specifically, high seas closure increases the resilience of fish stocks, as indicated by a mean species abundance index, by 30% in EEZs. We suggest that improving high seas fisheries governance would increase the resilience of coastal countries to climate change. 相似文献
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Which design elements of individual quota fisheries help to achieve management objectives? 下载免费PDF全文
下载免费PDF全文 Individual quota (IQ) management systems in commercial marine fisheries are highly diverse, differing in the security, durability and exclusivity of the harvesting privilege and the transferability of quota units. This diversity in the degree of harvest rights may influence the effectiveness of IQ fisheries to meet management objectives. We conducted a global meta‐analysis of 167 stocks managed under IQs to test whether the strength of harvest rights impacts the conservation status of stocks in terms of catch, exploitation rate and biomass relative to management targets. We used non‐parametric methods to assess non‐linear relationships and linear regression models to explicitly consider interactions among predictors. Most IQ fisheries consistently met fleet‐wide quota limits (94% of stocks had recent catches below or within 10% of quotas), but only 2/3 of IQ fisheries adhered to sustainable management targets for biomass and exploitation rate (68% of stocks had exploitation rates below or within 10% of targets and 63% of stocks had biomass above or within 10% of biomass targets). Strikingly, when exclusivity of the harvesting privilege was low, exploitation rates depended on whether IQ implementation was industry‐driven (exploitation below targets) or government‐mandated (exploitation above targets). At high levels of exclusivity, exploitation rates converged to just below management targets. Transferability of quota units was associated with stock biomass closer to and slightly above target levels than stocks with non‐transferable quota. However, regional differences had the strongest effect on biomass, suggesting that other management or biological attributes of regional fishery systems have greater influence on marine populations. 相似文献
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- 1. Marine protected areas (MPAs) are expected to function simultaneously as biological conservation and fisheries management tools, but empirical evidence linking biodiversity conservation with fisheries benefits is scarce. Around the Medes Islands marine reserve (Spain, NW Mediterranean) patterns of fish catch diversity, catch (CPUE) and income (IPUE) were assessed and the economic value of diversity for local fisheries was explored by combining a Geographic Information System (GIS) analysis with geostatistics.
- 2. Catch data were derived from the trammel net fleet operating around the MPA to gain information on species diversity, functional diversity, functional redundancy, CPUE and IPUE.
- 3. Results revealed significant impact of both the fishing prohibition in the MPA and the presence of seagrass beds on diversity metrics, catch and income. Clear differences in functional redundancy in fish assemblages were found within the study area, indicating greater resilience of the fish assemblage against fishing pressure or human impact close to the MPA (?2 km). In contrast, fish assemblages beyond 2 km of the MPA border are more vulnerable to disturbance. High values of diversity, CPUE and IPUE overlapped close to the MPA border and close to seagrass beds.
- 4. The spatial approach developed suggests that, in addition to the more commonly studied effect of density‐dependent spillover of adult fish, increased levels of ecological diversity and economic diversity can also result in fisheries benefits of an MPA. Hence, the fishing regulations in and around the Medes Islands marine reserve have shown that biological conservation and fisheries benefits can be complementary in the long‐term, which should be considered in future policies for MPAs or MPA networks.
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Paul Tixier Mary‐Anne Lea Mark A. Hindell Dirk Welsford Camille Maz Sophie Gourguet John P. Y. Arnould 《Fish and Fisheries》2021,22(1):31-53
The sustainable mitigation of human–wildlife conflicts has become a major societal and environmental challenge globally. Among these conflicts, large marine predators feeding on fisheries catches, a behaviour termed “depredation,” has emerged concomitantly with the expansion of the world’s fisheries. Depredation poses threats to both the socio‐economic viability of fisheries and species conservation, stressing the need for mitigation. This review synthesizes the extent and socio‐ecological impacts of depredation by sharks and marine mammals across the world, and the various approaches used to minimize it. Depredation was reported in 214 fisheries between 1979 and 2019 (70% post‐2000) and affected fleets from 44 countries, in all sectors (commercial, artisanal and recreational), and in all major fishing techniques (nets, traps and hook‐and‐lines). A total of 68 predator species were involved in depredation (20 odontocetes, 21 pinnipeds and 27 sharks), and most (73%) were subject to either by‐catch and/or retaliatory killing from fishers when interacting with gear. Impacts on fishers were primarily associated with catch losses and gear damage but often lacked assessments. Deterrence was a major mitigation approach but also the least effective. Gear modifications or behavioural adaptation by fishers were more promising. This review highlights the need for improved monitoring, and interdisciplinary and integrated research to quantify the determinants and impacts of depredation in the socio‐ecological dimension. More importantly, as the conflict is likely to escalate, efforts directed towards changing perceptions and integrating knowledge through adaptive co‐management are raised as key directions towards coexistence between fisheries and large marine predators. 相似文献
16.
Marine reserves are valued for their ecological role: protecting fish populations from overharvesting while, at the same time, potentially maintaining fisheries yields via recruitment effects (net export of pelagic eggs and larvae) and spillover (net export of post‐settled juveniles and mature fish) across reserve borders. Focussing on the spillover effect, we argue that when fitness of the protected individuals depends on the relative size of their home ranges compared to the reserve size, and home range size is a property of the individuals, rapid local adaptation might occur in favour of individuals with smaller home ranges. Individuals that avoid fishing mortality by spending most of the time inside the reserve limits (i.e. with smaller home ranges) will experience a fitness advantage, whereas individuals that move beyond boundaries (i.e. with larger home ranges) will increase their risk of being harvested by spillover fisheries. We use empirical data on Atlantic cod (Gadus morhua) home ranges within and around a coastal marine reserve in south Norway as a case to illustrate our idea. Broadly, we highlight how protection‐induced selection and contemporary evolution could fundamentally alter our perspective of marine reserve functioning and recommend quantifying behavioural variability and behavioural consistency of protected populations. 相似文献
17.
蓝色增长背景下的海洋生物生态城市化设想与海洋牧场建设关键技术研究综述 总被引：8，自引：4，他引：4
近年来,世界范围内为解决过度捕捞、污染、不可持续的沿岸渔业方式对栖息地、栖息地生态功能以及物种多样性产生的不可逆转破坏,以及传统渔业、养殖业转型难、环境污染大、渔业资源衰退、渔民生计受到威胁等严峻问题,开展了大量的实验与理论研究。其中以FAO提出的"蓝色增长"与我国提出的"海洋牧场"理念框架最具针对性与代表性。伴随着新趋势与理念的产生,相关技术必须及时提供支撑。然而,围绕"蓝色增长"与"海洋牧场"的环境整体性与技术可行性及其关键支撑技术,尚未得到很好的整合与开发。本文通过对学界海洋牧场建设目标、核心工作以及其潜在问题进行梳理,整合目前"蓝色增长"与"海洋牧场"的主流技术,借鉴城市生态学中这一已经发展较为成熟学科的相关技术与体系,提出海洋生物的生态城市化设想及海洋生物生态城镇化设想的海洋牧场选址与规划、生境营造、生物资源增殖与行为控制以及管理四大关键技术,并详细分析了相关技术的实用性与技术整合的实用性,以期为海洋牧场相关研究者提供系统性的技术支撑与参考。 相似文献
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Bryony A. Caswell Emily S. Klein Heidi K. Alleway Johnathan E. Ball Julin Botero Massimiliano Cardinale Margit Eero Georg H. Engelhard Tomaso Fortibuoni Ana‐Judith Giraldo Jonas Hentati‐Sundberg Peter Jones John N. Kittinger Gesche Krause Dmitry L. Lajus Julia Lajus Sally C.Y. Lau Ann‐Katrien Lescrauwaet Brian R. MacKenzie Matthew McKenzie Henn Ojaveer John M. Pandolfi Sa&#x;a Raicevich Bayden D. Russell Andreas Sundelf Robert B. Thorpe Philine S.E. zu Ermgassen Ruth H. Thurstan 《Fish and Fisheries》2020,21(4):774-796
The concept of “blue growth,” which aims to promote the growth of ocean economies while holistically managing marine socioecological systems, is emerging within national and international marine policy. The concept is often promoted as being novel; however, we show that historical analogies exist that can provide insights for contemporary planning and implementation of blue growth. Using a case‐study approach based on expert knowledge, we identified 20 historical fisheries or aquaculture examples from 13 countries, spanning the last 40–800 years, that we contend embody blue growth concepts. This is the first time, to our knowledge, that blue growth has been investigated across such broad spatial and temporal scales. The past societies managed to balance exploitation with equitable access, ecological integrity and/or economic growth for varying periods of time. Four main trajectories existed that led to the success or failure of blue growth. Success was linked to equitable rather than open access, innovation and management that was responsive, holistic and based on scientific knowledge and monitoring. The inability to achieve or maintain blue growth resulted from failures to address limits to industry growth and/or anticipate the impacts of adverse extrinsic events and drivers (e.g. changes in international markets, war), the prioritization of short‐term gains over long‐term sustainability, and loss of supporting systems. Fourteen cross‐cutting lessons and 10 recommendations were derived that can improve understanding and implementation of blue growth. Despite the contemporary literature broadly supporting our findings, these recommendations are not adequately addressed by agendas seeking to realize blue growth. 相似文献
19.
Owen R. Liu Kristin M. Kleisner Sarah L. Smith Jacob P. Kritzer 《Fish and Fisheries》2018,19(5):821-838
The role of spatial management, including marine protected areas, in achieving fisheries outcomes alongside conservation goals is debated. In fisheries that fail to meet fishing mortality targets, closed areas are sometimes implemented to reduce fishing mortality. However, fisheries with stronger management, including rights‐based approaches that can address overcapacity and overfishing problems, often employ spatial management as well. Here, we compare the objectives, design, and performance of spatial management in nine temperate demersal fisheries in North America, Oceania, Europe, and Africa that employ rights‐based systems. Common objectives of spatial management included protecting habitat, juveniles, and spawners and reducing discards. Recovering age structure and creating scientific reference sites were less common objectives, despite being widely cited benefits of spatial management. Some fisheries adopted single closures to achieve single objectives, whereas others adopted diverse networks to achieve multiple objectives. Importantly, many spatial protections are implemented primarily through industry initiatives. Environmental change compromised the efficacy of spatial management in some cases, suggesting the need to design spatial management systems that are robust to changing ocean conditions. Fisheries with diverse and extensive spatial management systems have generally healthier fish stocks. Whether this implies that spatial management contributed substantially to fishery performance is unclear due to an absence of large‐scale, long‐term studies aimed at discerning different drivers of success. Although these targeted monitoring studies of closed areas are limited, such studies are necessary to help resolve the ongoing debate and to enable more purposeful design of spatial management for fisheries and conservation. 相似文献
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R Ian Perry Rosemary E Ommer Manuel Barange Svein Jentoft Barbara Neis U Rashid Sumaila 《Fish and Fisheries》2011,12(4):427-450
Marine social–ecological systems consist of interactive ecological and human social elements so that changes in ecological systems affect fishing‐dependent societies and vice versa. This study compares the responses of marine ecological and fishing‐dependent systems to environmental change and the impacts of globalization, using four case‐studies: NE Atlantic (Barents Sea), NW Atlantic (Newfoundland), SE Atlantic (Namibia) and the equatorial Atlantic (Ghana). Marine ecological systems cope with short‐time changes by altering migration and distribution patterns, changing species composition, and changing diets and growth rates; over the longer term, adaptive changes lead to increased turn‐over rates and changes in the structure and function of the system. Fishing communities cope with short‐term change through intensification and diversification of fishing, migration and ‘riding out the storm’. Over the longer term, adaptive changes in policy and fisheries governance can interact with social–ecological change to focus on new fisheries, economic diversification, re‐training, out‐migration and community closures. Marine social–ecological systems can ultimately possess rapid adaptive capacity in their ecological components, but reduced adaptive capacity in society. Maintaining the diversity of response capabilities on short and longer time scales, among both ecological and human fishing systems, should be a key policy objective. The challenge is to develop robust governance approaches for coupled marine social–ecological systems that can respond to short‐ and long‐term consequences of global change. 相似文献