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1.
    
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   

2.
    
  1. The African manatee has been poorly studied throughout its range and is heavily hunted. This study aimed at discerning patterns in manatee sightings and emerging conflicts with humans, as well as the local perception of manatees, outside the southern periphery of Korup National Park, Cameroon.
  2. The study investigated whether patterns in manatee sightings and manatee‐related conflicts differ between aquatic systems in southern Korup, and which demographic variables determine perceptions of the manatee in the study area. For this purpose, the study used a three‐stage stratified random sampling design with a structured questionnaire to survey 101 local fishers.
  3. The reported patterns of manatee sightings and manatee‐related conflicts were as follows: in the Nyangorobe River during the wet season only, where crop raiding and net destruction by manatees were reported; in the Ndian River and the mangrove estuary only during the dry season, where fish theft and net damage were reported; and in the Moko River during both seasons, where crop raiding, fish theft, and net destruction were reported. Reducing these conflicts is likely to increase local support for the conservation of manatees, because fishermen kill them in response to net destruction and fish loss.
  4. Most reported sightings were at waterway intersections and river bends, suggesting that waterway connectivity is important to manatees for dispersal, foraging, and escape from danger.
  5. The log‐odds probability of negative perception decreased significantly with awareness of manatee protected status but increased with age and primary or higher education level. These findings have implications for community outreach focused on raising awareness of the importance of manatee conservation by schoolchildren and the public.
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3.
    
  1. Although the economic value of wildlife historically has been attributed to its consumptive use, the global growth of ecotourism has expanded wildlife valuation to include non‐consumptive uses. In California, the critically endangered giant sea bass (Stereolepis gigas) is paradoxically both a flagship species in the recreational dive industry and regularly sold in California's commercial fisheries when incidentally caught. The differences in the economic value of S. gigas to these two key stakeholders – commercial fishers and recreational scuba divers – were explored.
  2. The average annual landing value of S. gigas was US$12 600, this value was determined using California commercial fishery landing receipt data. In contrast the estimated average value of S. gigas to recreational divers was US$2.3 million per year. The non‐consumptive use value was calculated by approximating the annual number of recreational charter boat divers and determining divers' willingness‐to‐pay for a S. gigas sighting.
  3. Stated landings volumes of S. gigas appear to represent a minimum annual extraction of 2% to 19% of the S. gigas population. Using self‐reported fishery catch location data, S. gigas bycatch hotspots were identified and used to inform suggestions for strategic spatial and temporal closures.
  4. Overall, these results highlight the value of giant sea bass beyond fisheries and underscore the importance of incorporating non‐consumptive values when developing harvest policies and marine management plans.
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4.
    
Ocean sustainability is a widespread public concern in Europe, and the issue of fisheries discards is one that is now widely known. With this increase in public awareness comes the need to adapt fisheries management policies to manage issues like fisheries discards that were not previously taken into account. In this context, this study analyses the evolution of the European Union's discard policy since its inception in 2006 until the present day and the events that shaped its current format. It analyses the policy's advantages and disadvantages, and its political, environmental and scientific consequences. It argues that an increase in public awareness, due to public campaigns against fisheries discards, has focused managers' attention onto a symptom of fisheries mismanagement, rather than on its underlying causes of over‐exploitation and lack of fisheries control. This has distorted the discussion of the reform of the Common Fisheries Policy and potentially undermined its provisions relating to discards.  相似文献   

5.
欧盟共同渔业政策自1983年正式实施以来,对促进欧盟政治、经济一体化、发展渔业经济、改善渔区人民生活水平、促进水产品贸易标准化、提高水产品质量、保护消费者健康和环境以及增强欧盟渔业国际竞争力发挥了积极作用。但30年来,随着欧盟渔业的发展和新问题的出现,共同渔业政策也经历了多次调整和改革,如2002年的改革、2008年应对燃油危机措施、2010年的IUU法规,以及最新的2013年改革。本文将从欧盟共同渔业政策的起源、早期内容和改革历程及最新的改革内容等方面来详细介绍共同渔业政策的演变,并对其最新改革方向进行总结预测,以期为我国渔业政策发展提供借鉴。  相似文献   

6.
    
Farming freshwater prawns with fish in rice fields is widespread in the coastal region of southwest Bangladesh because of favourable resources and ecological conditions. This article provides an overview of an ecosystem‐based approach to integrated prawn–fish–rice farming in southwest Bangladesh. The practice of prawn and fish farming in rice fields is a form of integrated aquaculture–agriculture, which provides a wide range of social, economic and environmental benefits. Integrated prawn–fish–rice farming plays an important role in the economy of Bangladesh, earning foreign exchange and increasing food production. However, this unique farming system in coastal Bangladesh is particularly vulnerable to climate change. We suggest that community‐based adaptation strategies must be developed to cope with the challenges. We propose that integrated prawn–fish–rice farming could be relocated from the coastal region to less vulnerable inland areas, but caution that this will require appropriate adaptation strategies and an enabling institutional environment.  相似文献   

7.
    
Recreational fishing is a commonplace leisure activity within the developed world but can generate tension when activities conflict with conservation agendas. A potential conflict arises over the use of European river lamprey, Lampetra fluviatilis (L.), a protected species, by UK coarse (freshwater non-salmonid) predator anglers. This study used geographically stratified interviews with 69 predator anglers to explore attitudes towards the use of lamprey as bait, their conservation status and knowledge of biosecurity regulations. Most participants used lamprey as bait to some degree and agreed that, if threatened by exploitation, a ban on their use as angling bait should be implemented. Ordinal regression analysis indicated the presence of a subset of anglers who value lamprey as bait more than others and may oppose conservation efforts. The benefits of the potential establishment of bait certification schemes are also considered.  相似文献   

8.
    
1. Traditional community‐based systems of managing coastal fisheries were (or in some cases are) successful in managing resources at sustainable levels. These systems are used as models in the present study. 2. They were (or are) under‐pinned by a sense of ownership and intimate knowledge of the environment in local people. 3. Such features have been largely lost, as subsistence economies have been replaced by capitalist ones, and environmental management responsibilities have shifted from local communities to national or international government. 4. There are, nevertheless, some examples of community‐based management systems that still operate successfully and we believe that modern management practices, in general, would benefit from increased community involvement. This will require renewed emphases on feelings of ownership and increased knowledge of the environment in the general public. 5. Environmental education will have a fundamental role to play in achieving this goal. However, its impact in schools and universities has been disappointingly ineffective so far in promoting a population that is sufficiently knowledgeable and well‐motivated to partake meaningfully in environmental management processes. 6. It is argued that educational initiatives, which involve all ages and sections of society, are required. Five promising possibilities are: (i) the participation of community groups in scientific projects; (ii) increased emphasis on life‐long learning; (iii) educational campaigns; (iv) citizens' juries; and (v) the involvement of community groups in environmental planning and management processes. 7. Wide‐scale adoption of innovations of these kinds will require funding and this will be achieved only by national re‐assessments of educational needs and priorities. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   

9.
    
Co‐management (Co‐M), defined as the sharing of management tasks and responsibilities between governments and local users, is emerging as a powerful institutional arrangement to redress fisheries paradigm failures, yet long‐term assessments of its performance are lacking. A comparative analysis of five small‐scale Latin American shellfisheries was conducted to identify factors suggesting success and failure. In Chile, Uruguay and Mexico Co‐M produced positive effects, including stabilization of landings at low levels, increase in abundance, CPUE, unit prices and revenues per unit of effort, and reduced interannual variability in several fishery indicators, particularly in landings. Co‐M was successful because it was mainly bottom‐up implemented and accompanied by‐catch shares (spatial property rights and community quotas). By contrast, Co‐M implementation was unable to prevent the collapse of the Galapagos sea cucumber fishery, as reflected by a decrease in abundance and CPUE. Negative effects were also observed in the Galapagos spiny lobster fishery during Co‐M implementation. However, recovery was observed in recent years, reflected in a stabilization of fishing effort and the highest CPUE and economic revenues observed since the beginning of the Co‐M implementation phase. The combined effects of market forces, climate variability and a moratorium on fishing effort were critical in fishery recovery. We conclude that Co‐M is not a blueprint that can be applied to all shellfisheries to enhance their governability. These social–ecological systems need to be managed by jointly addressing problems related to the resources, their marine environment and the people targeting them, accounting for their socioeconomic and cultural contexts.  相似文献   

10.
    
  1. Small‐scale fisheries may pose a serious threat to the conservation of marine mammals. At the same time various factors have led to the decline of small‐scale fisheries, often making them unsustainable. Current rates of biodiversity loss and the reduction of fish stocks and fisheries dictate a thorough understanding of fisheries‐related issues and the implementation of effective management actions.
  2. The Mediterranean monk seal is one of the most endangered marine mammals on Earth; its survival in the eastern Mediterranean Sea is threatened by negative interactions with fisheries. A nationwide questionnaire survey among fishers and port police authorities was carried out in Greece to describe the main characteristics of small‐scale fisheries, and to understand the nature and assess the magnitude of negative interactions between the monk seal and these fisheries. Questionnaire information was verified by a second round of interviews during landings.
  3. The main attributes of the fishers, their fishing boats, and their practices were characteristic of the small‐scale fisheries sector. Overfishing was considered the main reason for fish‐stock reduction, and negative interactions with marine mammals was considered the main issue for the fishing sector.
  4. Monk seals were present, caused damage, and got accidentally entangled in fishing gear throughout Greece. Damage to fishing gear was recorded mainly during spring and summer, and on average affected 21% of all fishing trips and 1% of nets deployed during a fishing trip.
  5. Based on these results, the implementation of general and specific nationwide fishery management and conservation actions are proposed. These actions are mainly aimed at improving fish stock status, changing the behaviour of the fishers, and mitigating seal–fishery interactions in Greece, while promoting the recovery of the Mediterranean monk seal in the eastern Mediterranean Sea.
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11.
    
  • 1. Wildlife tourism can be prone to unmitigated development to promote visitor satisfaction that is all too often progressed at the cost of ecological integrity. A manager is thus faced with the dual task of enhancing the tourist experience and protecting the wildlife species. Accordingly, this mandate requires research into how tourists would respond to proposed wildlife‐management plans.
  • 2. This study examines the heterogeneity of tourist preferences for wildlife management at a stingray‐feeding attraction in the Cayman Islands, using a latent class stated preference choice model. A sample of visitors to Stingray City Sandbar (SCS) evaluated hypothetical wildlife viewing experiences in a discrete choice experiment. Its scenarios were characterized by seven attributes such as animal‐feeding and handling rules, ecological outcomes, social crowding, and management cost (defined as a conservation access fee).
  • 3. The latent class segmentation identified two groups in the population: approximately 68% preferred the implementation of fairly strict management rules, while the other 32% valued more the maintenance of status quo with its intensive human — wildlife interactions. Despite the differences between the ‘pro‐management’ and the ‘pro‐current’ segments, both exhibited a preference for the continuation of feeding and handling the stingrays (albeit at different levels of intensity) suggesting that one effective way to implement any management actions is to alter the promotional and marketing strategies for SCS. Other survey questions on trip experience, conservation values, and socio‐demographics were used to define these classes further, with the main distinguishing trait being the level of concern for potential impacts occurring at SCS. The discrepancies between the two segments became most obvious when calculating their respective market shares of support for alternative management strategies.
  • 4. This approach to determining visitor preferences can help explain how the various segments will be affected by management options, and therefore can provide the basis for developing feasible strategies that will assist wildlife managers in maximizing tourist satisfaction while achieving wildlife‐protection goals.
Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

12.
    
A holistic basis for achieving ecosystem‐based management is needed to counter the continuing degradation of coral reefs. The high variation in recovery rates of fish, corresponding to fisheries yields, and the ecological complexity of coral reefs have challenged efforts to estimate fisheries sustainability. Yet, estimating stable yields can be determined when biomass, recovery, changes in per area yields and ecological change are evaluated together. Long‐term rates of change in yields and fishable biomass‐yield ratios have been the key missing variables for most coral reef assessments. Calibrating a fishery yield model using independently collected fishable biomass and recovery data produced large confidence intervals driven by high variability in biomass recovery rates that precluded accurate or universal yields for coral reefs. To test the model's predictions, I present changes in Kenyan reef fisheries for >20 years. Here, exceeding yields above 6 tonnes km?2 year?1 when fishable biomass was ~20 tonnes/km2 (~20% of unfished biomass) resulted in a >2.4% annual decline. Therefore, rates of decline fit the mean settings well and model predictions may therefore be used as a benchmark in reefs with mean recovery rates (i.e. r = 0.20–0.25). The mean model settings indicate a maximum sustained yield (MSY) of ~6 tonnes km?2 year?1 when fishable biomass was ~50 tonnes/km2. Variable reported recovery rates indicate that high sustainable yields will depend greatly on maintaining these rates, which can be reduced if productivity declines and management of stocks and functional diversity are ineffective. A number of ecological state‐yield trade‐off occurs as abrupt ecological changes prior to biomass levels that produce MSY.  相似文献   

13.
    
Achieving high compliance with resource‐use management policies is a critical concern to achieving sustainability, particularly in poor countries. Willingness to comply may depend on the values and perceptions of benefits and legitimacy of the restrictions. Consequently, we interviewed and evaluated the perceptions of fishing restrictions among ~2100 marine fisheries stakeholders (resource users and managers) in 102 fishing villages in Kenya, Madagascar, Mozambique and Tanzania. We hypothesized that perceived benefits would decline and social inequity increase along a hypothesized gradient of increasing access restriction – ranging from minimum size of fish to fisheries closures. Managers did not recognize the hypothesized access restriction gradient, seeing most restrictions as beneficial, but with some nation‐specific distinctions. Village‐level responses of resource users varied by country, and overall perceived benefits of access restrictions increased with the wealth, education and membership in fishing organizations. In Kenya and Tanzania, some communities with views that differed greatly from managers were, in places, found near marine protected areas and they perceived more benefits accruing to the government than resource users for the strongest access restrictions. Madagascar and Mozambique fishing villages had low between‐community variability, and their responses did not reflect the hypothesized restriction gradient or strong social disparity, which may reflect limited practical experience with restrictions. These results suggest that countries with stronger central governments contained villages with more between‐community variability and perceived social disparity than weaker governments. We argue that transparent negotiations with stakeholders about the scales of costs and benefits should increase compliance with selected fisheries regulations.  相似文献   

14.
    
The objective of this study was to demonstrate the feasibility of partial substitution of menhaden fish oil by alternative lipid sources (soybean oil, poultry grease and flaxseed oil) in non‐marine protein‐based shrimp production diet, its influence on fatty acid profile and its final product flavour. Results for the pond study (17 weeks) showed no differences ( 0.05) in shrimp production among different test diets. Production ranged from 5070 to 5363 kg ha?1; mean final weight, 18.0 to 21.6 g; weekly growth, 1.04 to 1.25 g; survival, 65.6 to 75.4%; and FCR, 1.37 to 1.45. Results from the tank trial (12 weeks) confirmed these findings, final weight, 13.8–14.8 g; weekly growth, 1.1–1.2 g; survival, 92.5–98.3%; FCR, 1.05–1.11; and final standing crop, 4738–5024 kg ha?1. The fatty acids profiles of edible tail muscle reared on the various diets displayed a similar fatty acid profile to that of the diets. The sensory test showed no statistical differences in texture, appearance, aroma and flavour between the shrimp fed diets containing menhaden fish oil and soybean oil. These studies demonstrated that practical shrimp feeds containing non‐marine protein ingredients and a percentage of fish oil replaced by alternative lipid sources had no negative impact on mean final weight, weekly growth, survival, FCR, final standing crop, fatty acids profile and organoleptic properties of Litopenaeus vannamei.  相似文献   

15.
    
Pectin is a promising candidate to be employed as binder for manufacturing pellets for crayfish feeding. In this study, the gelling properties of different types of pectin and their effects on Cherax quadricarinatus performances have been analysed. Pectins with different degree of esterification from apple and citrus were screened to select those with the best gelling properties to be employed in pellet manufacturing. Three pectins were selected: low esterification degree apple pectin (LEAP), low esterification citrus pectin (LECP) and high esterification degree apple pectin (HEAP). Scanning electron microscopy analysis, nutrient leaching and water uptake indicated that LEAP showed the best aggregating properties, followed by LECP and HEAP pellets. Cherax quadricarinatus performances were affected by the pectin type, with redclaw fed LEAP pellets showing the highest (P < 0.05) growth rate and amylase activity (P < 0.05) in the gastrointestinal tract. Altogether these results indicate that LEAP can be considered an excellent binder for feed pellets due to its gelling properties and its efficacy to improve growth and stimulation of digestive enzyme activity.  相似文献   

16.
    
Despite recreational fisheries serving as a prime example of a coupled social–ecological system, much of the research on such fisheries has been monothematic in orientation and focused either on fisheries ecology or human dimensions. An attempt was made to break down some of the barriers to more interdisciplinary research on recreational fisheries at the 6th World Recreational Fishing Conference. The overall conclusion was that future research and management efforts should increasingly focus on the feedbacks between the interacting human and ecological components of recreational fisheries. Doing so promises to improve understanding of how recreational fisheries respond to social–ecological change. In this context, the behaviour of both fishes and humans provides an important, yet often overlooked, integrator of the ecological and social components of recreational fisheries. A better understanding of the behavioural dynamics of recreational fishers as well as exploited fishes will help predict how recreational fisheries change, evolve, adapt and reorganise through time to maintain resilience and achieve sustainability on a global scale.  相似文献   

17.
    
Balancing trade‐offs amongst social–ecological objectives is a central aim of natural resource management. However, objectives and resources often have spatial dimensions, which are usually ignored in trade‐off analyses. We examine how simultaneously integrating social–ecological benefits and their spatial complexities can improve trade‐off analysis. We use Pacific herring (Clupea pallasii, Clupeidae)—an ecologically important forage fish with social, cultural and economic value to communities and commercial fisheries—as a case study. By combining spatial management strategy evaluation with social benefits analysis, we illustrate when policies aimed at aggregate stocks versus spatially segregated substocks of fish fail to balance trade‐offs amongst social–ecological objectives. Spatial measures (e.g. area‐based closures) may achieve some objectives but produce alternative trade‐offs that are sensitive to assumptions about fish population dynamics and social complexities. Our analyses identify policies that are inefficient (e.g. yielding economic costs without producing social or ecological gains), highlight management strategies that generate trade‐offs and indicate when costs are distributed unequally for different user groups. We also point to strategies with outcomes that are robust to spatial uncertainties and reveal research priorities by identifying which performance metrics exhibit sensitivity to spatial ecological assumptions. Collectively, our analyses demonstrate how incorporating social objectives and spatial dynamics into management strategy evaluation can reveal trade‐offs and the implications of management decisions.  相似文献   

18.
    
Fishmeal (FM) and soy meal (SM) are the most common protein sources used in fish feed, but they are associated with environmental, economic or production problems. Insects could be an interesting alternative source of protein. This work investigates the nutritive value of Tenebrio molitor meal (TM) and the effect of total replacement of SM by TM (TM/FM diet) or partial replacement of FM by TM (TM/FM/SM diet) versus a diet based in SM and FM (FM/SM diet) for tilapia. We studied the chitin content in TM, the in vitro protein digestibility, protease activity, oxidative stress and antioxidant defences, growth performance and nutrient utilization. The results indicate that an inclusion up to 500 g kg?1 of TM in the diet did not affect feed intake, in vitro protein digestibility, muscle amino acid composition or biometric indexes. However, their inclusion reduced growth performance and affected the muscle fatty acid profile. The lowest values for protease activity, elevated FRAP in digestive tracts and ROS level in muscle and higher SOD activity were observed in fish fed with SM/FM diet. The use of TM requires better understanding of the role of chitin in digestion and the study of toxins that might affect fish growth.  相似文献   

19.
    
Inland capture fisheries provide food for nearly a billion people and are important in the livelihoods of millions of households worldwide. Although there are limitations to evaluating many of the contributions made by inland capture fisheries, there is growing recognition by the international community that these services make critical contributions, most notably to food security and livelihoods in rural populations in those low‐income countries with extensive freshwater resources. With the increasing appreciation of the key role of inland fisheries to the health and well‐being of human populations globally, the Food and Agriculture Organization of the United Nations and Michigan State University convened the 2015 global conference, Freshwater, fish, and the future – cross‐sectoral approaches to sustain livelihoods, food security, and aquatic ecosystems. What emerged from the interactions between inland fisheries’ scientists, resource managers, policymakers and community representatives from across the world was a forward‐looking call to action culminating with the 2015 Rome Declaration “Ten Steps to Responsible Inland Fisheries” (FAO & MSU, Rome declaration on responsible inland fisheries: 5735E/1/06.16). Four years after this landmark conference and declaration, we seek to advance discussion on the “Ten Steps,” namely what successful implementation looks like, assess current examples of implementation, suggest potential signals of progress and provide some specific, indicative examples of progress for each step. While there are promising signs of progress, we conclude that there remains a strong need to galvanize momentum for sustained action to ensure that inland fish and fisheries are accounted for and incorporated into broader water resource management discussions and frameworks.  相似文献   

20.
    
The impacts of climate change on cold‐water fishes will likely negatively manifest in populations at the trailing edge of their distributions. Rio Grande cutthroat trout (Oncorhynchus clarkii virginalis, RGCT) occupy arid south‐western U.S. streams at the southern‐most edge of all cutthroat trout distributions, making RGCT particularly vulnerable to the anticipated warming and drying in this region. We hypothesised that RGCT possess a portfolio of life‐history traits that aid in their persistence within streams of varying temperature and stream drying conditions. We used otolith and multistate capture–mark–recapture data to determine how these environmental constraints influence life‐history trait expression (length‐ and age‐at‐maturity) and demography in RGCT populations from northern New Mexico, United States. We found evidence that RGCT reached maturity fastest at sites with warm stream temperatures and low densities. We did not find a strong relationship between discharge and any demographic rate, although apparent survival of mature RGCT decreased as stream temperature increased. Our study suggests plasticity in trait expression may be a life‐history characteristic which can assist trailing edge populations like RGCT persist in a changing climate.  相似文献   

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