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1.
Small-scale fisheries in coral reef areas support the livelihoods of millions of people worldwide. Anthropogenic impacts such as overfishing and climate change increasingly threaten both the reef ecosystem and the livelihood security of the people that depend on the reefs. Adaptive management strategies are needed to adequately deal with these threats, but they require an understanding of the underlying drivers, which often originate and act on multiple levels. Using a social-ecological system approach, the coral reef fishery of the Spermonde Archipelago in South Sulawesi/Indonesia is assessed to identify key drivers and strategic leverage points for management. Under the influence of international markets and technological changes, several export-oriented fisheries have developed in the area that led to distinct subsequent peaks in fishing activity in a pattern of sequential marine resource exploitation. In response to stressors such as seasonality and overfishing of individual locations or species, a number of coping strategies have developed locally. These include extensive borrowing from fishing patrons, diversification of fishing methods, fishing migrations, and the crafting of local institutions to regulate fishing activity. However, the coping strategies hinder, and even decrease, the capacity of the system to adapt to future stressors and undermine the sustainability of the fishery. Potential strategies that target different levels of the fishery system in order to strengthen adaptive management are identified.  相似文献   

2.
The composition and abundance of marine biota in Israeli marine ecosystems are affected by natural and anthropogenic pressures, including blooms of non-indigenous jellyfish and overfishing. While overfishing is itself a major stressor of fish stocks, it appears that jellyfish may be outcompeting fish for scarce planktonic food resources. Beyond this direct impact on fisheries, jellyfish–ecosystem interactions are also important because of the disturbance they cause to multiple users of marine and coastal resources. This paper documents the concurrent changes in the composition of marine biotic communities, including jellyfish proliferation and dwindling stocks of endemic, commercially valuable fish and the rising rate of bottom trawling in Israeli fisheries. The capacity to deal directly with jellyfish is limited by lack of knowledge about their ecology. Therefore, we suggest that bolstering fish stocks and increasing their competitive advantage in the food web may be instrumental in limiting jellyfish blooms. Coordination of fishing and conservation policies is recommended, as are modifications to marine waste management and deployment of submerged artificial substrates.  相似文献   

3.
长江流域水库密集,蕴藏着巨大的渔业资源,由于人口增加,耕地减少,保护土地成为国策,今后靠用耕地开挖池塘养鱼来增加水产品产量已不可能;我国传统的四大海洋经济鱼类,因过度捕捞,已不成渔汛,湖泊不断减少,江河环境受到不同程序的污染,使湖泊,灌河渔业产量下降。相反,随着岁月流长,人类进步,经济繁荣,人工湖-即水库将会不断增加。  相似文献   

4.
Currently, artisanal fisheries in fresh water reservoirs have been losing ground to commercial fish farming and a great deal of fishery resources are being threatened by human interventions, such as reservoir management and increasing net-cage aquaculture. This study aims to understand the impacts of environmental changes on fishery resources and analyse the migratory fish breeding season as a missing link for fishery management in the semi-arid area of the São Francisco River Basin. Among the 870 fishermen operating in the Pernambuco part of the Itaparica Reservoir, 10% were interviewed and affirmed that fish stocks have been compromised due to the closed fishing period’s incoherence, exotic species insertion, and changes to the river flow caused by reservoir construction and operation. A significant correlation was observed between the Reproductive Activity Index (RAI) and precipitation (p?=?0.745) as well as between the RAI and the river’s flow (p?=??0.909). This shows how important it is to consider both the semi-arid climate setting and reservoir operation in determining the closed period which should safeguard fish reproduction. Monitoring the fish reproduction period and research on the reproductive biology of native fish species is needed in the São Francisco River Basin’s different stretches in order to guarantee valuable fish stocks and fisheries maintenance. Integrated action between the fish resource users, civil society, and federal bodies/agencies is essential in order to mitigate impacts and improve fish production systems, not only in Brazil, but in other regions experiencing a similar scenario.  相似文献   

5.
浅谈长江中下游地区渔业与水域环境的协调发展   总被引:3,自引:0,他引:3  
长江中下游地区自然条件优越,淡水资源丰富,过去,现在和将来都是我国重要的渔业基地,但是工业污染和盲目开发渔业已对水环境造成严重危害,降低了水体的多重社会功能,也损害了渔业自身,为了建立可持续发展的健康渔业,必须迅速转变渔业经济增长方式,从粗放型转到集约型和效益型,并按照生态学和经济学原理,运用现代科学技术与管理手段,结合传统渔业的精华,协调发展与环境之间,资源保护与利用之间的关系,形成生态和经济的  相似文献   

6.
Studies investigating the local ecological knowledge (LEK) held by fishermen about the fishing resources have indicated that fishermen’s LEK may have the potential to improve fishery management, by providing new information about the ecology, behavior and abundance trends of fish and other aquatic animals. Our major aim is to undertake a brief review of published ethnoichthyological studies with a focus on coastal Brazilian fisheries and freshwater fisheries in both Brazil and Southeast Asia. Based on such review, we provide 29 hypotheses on fish ecology based on fishermen’s LEK and compare them with what is already known from the biological literature, using an arbitrary ‘likelihood’ measure: “Low likelihood” corresponded to unexpected hypotheses, which contradict existing biological data. “Medium likelihood” corresponded to hypotheses that could not be compared to available scientific knowledge. Hypotheses that agree with scientific data were considered as “High likelihood”. We therefore discuss these three categories of hypotheses about several distinct topics, such as migration, reproduction, feeding habits, abundance patterns, ecological relationships between fish and their predators, and fishing pressure. Our results may contribute to the fisheries management and research in the studied regions and other similar places, besides raising the interest of biologists to properly include fishermen’s LEK when planning and conducting fisheries surveys. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.  相似文献   

7.
Systems of Knowledge: Dialogue, Relationships and Process   总被引:1,自引:0,他引:1  
During the last 20 years, the existence of rich systems of local knowledge, and their vital support to resource use and management regimes, has been demonstrated in a wide range of biological, physical and geographical domains, such as agriculture, animal husbandry, forestry and agroforestry, medicine, and marine science and fisheries.Local knowledge includes empirical and practical components that are fundamental to sustainable resource management. Among coastal-marine fishers, for example, regular catches and, often, long-term resource sustainment are ensured through the application of knowledge that encompasses empirical information on fish behaviour, marine physical environments, fish habitats and the interactions among ecosystem components, as well as complex fish taxonomies. Local knowledge is therefore an important cultural resource that guides and sustains the operation of customary management systems. The sets of rules that compose a fisheries management system derive directly from local concepts and knowledge of the resources on which the fishery is based.Beyond the practical and the empirical, it is essential to recognise the fundamental socio-cultural importance of local knowledge to any society. It is through knowledge transmission and socialisation that worldviews are constructed, social institutions perpetuated, customary practices established, and social roles defined. In this manner, local knowledge and its transmission, shape society and culture, and culture and society shape knowledge.Local knowledge is of great potential practical value. It can provide an important information base for local resources management, especially in the tropics, where conventionally-used data are usually scarce to non-existent, as well as providing a shortcut to pinpoint essential scientific research needs. To be useful for resources management, however, it must be systematically collected and scientifically verified, before being blended with complementary information derived from Western-based sciences.But local knowledge should not be looked on with only a short-term utilitarian eye. Arguments widely accepted for conserving biodiversity, for example, are also applicable to the intellectual cultural diversity encompassed in local knowledge systems: they should be conserved because their utility may only be revealed at some later date or owing to their intrinsic value as part of the world's global heritage.At least in cultures with a Western liberal tradition, more than lip-service is now being paid to alternative systems of knowledge. The denigration of alternative knowledge systems as backward, inefficient, inferior, and founded on myth and ignorance has recently begun to change. Many such practices are a logical, sophisticated and often still-evolving adaptation to risk, based on generations of empirical experience and arranged according to principles, philosophies and institutions that are radically different from those prevailing in Western scientific circles, and hence all-but incomprehensible to them. But steadfastly held prejudices remain powerful.In this presentation I describe the 'design principles' of local knowledge systems, with particular reference to coastal-marine fishing communities, and their social and practical usefulness. I then examine the economic, ideological and institutional factors that combine to perpetuate the marginalisation and neglect of local knowledge, and discuss some of the requirements for applying local knowledge in modern management.  相似文献   

8.
根据2000~2005年长江上游干流宜宾、巴南和万州3个江段三层流刺网的监测资料,分析了春禁前后3年渔获物结构和鱼类生物多样性的变化,对长江上游春禁效果进行了初步评价。春禁前后3年共监测到鱼类51种,隶属于3目18科(亚科)36属,以鲤科鱼类为主,占608%。春禁后,渔获物主要种类优势度有所下降,部分江段单位捕捞努力量渔获量表现出一定上升趋势,3个江段Margalef指数、Pielou指数和Wilhm改进指数有一定升高,表明种类丰富度有所提高,群落结构趋于复杂,春季禁渔有一定效果。春禁前后渔获物种类的波动,可能与这些种类种群数量少,难以采到有关;春禁后主要种类平均体长、体重仍表现出下降趋势,可能与过度捕捞及资源在短期内难以恢复有关。建议延长禁渔期、严格控制禁渔结束后的捕捞强度等措施来提高禁渔效果,并采取恢复江湖联系、保护重要渔业水域水质、实施水利工程生态调度等措施来配合春禁制度的实施。长江渔业资源的恢复和保护是一个长期而复杂的过程,对长江禁渔效果的准确评估还需要长期监测和深入研究。  相似文献   

9.
山东海洋休闲渔业的SWOT分析与对策   总被引:2,自引:0,他引:2  
休闲渔业是一种新型的渔业经营形式,在丰富渔业内容的同时,扩大了渔业发展的空间,给渔民、渔区带来更大的经济效益和社会效益。山东省发展休闲渔业具有一定的资源和区域优势,但同样存在一些问题和潜在的威胁。本文应用SWOT方法对山东省发展海洋休闲渔业的优势、劣势进行分析,并针对其发展面临的机遇和威胁提出了相应的对策。  相似文献   

10.
通江湖泊的渔业意义及其资源管理对策   总被引:24,自引:3,他引:21  
长江中、下游的江湖复合生态系统包含有河流和湖泊两个环境单元。其中的鱼类群落由河海洄游鱼类、江湖洄游鱼类、河流鱼类和定居性鱼类等4个生态类群组成,尤以江湖洄游鱼类对这一特殊的生态环境形成了良好的适应,因而种群数量繁盛,从渔业的角度看,水利工程造成的江湖阻隔削弱了通江湖泊的生态功能,成为导致鱼类资源下降和种类结构改变的主要原因之一。当前应从控制捕捞、人工增殖和恢复生态环境结构等方面着手进行资源管理,确  相似文献   

11.
Climate change will impact on ecological, social, and economic elements of fisheries; however, the three are seldom considered in an integrated fashion. We develop a fishery-level assessment of economic resilience to climate change for the Tasmanian rock lobster fishery, a linked social–ecological system. We outline the main climate change forcing influences that link climate change to the fishery via changes in lobster abundance, distribution, and phenology. Using a bottom-up approach, we identify twelve economic attributes strongly related to the fisheries’ economic resilience to climate change. Resilience attributes are grouped according to the level of the economic domain (business, sectoral, and governance). Attributes are then evaluated to determine the overall economic resilience of the rock lobster fishery in the context of the specific nature of predicted climate change effects. We identify areas of low resilience in the economic sub-system for this fishery. Evaluating the economic resilience of regional fisheries using this integrated, interdisciplinary framework provides a practical, parsimonious, and conceptually sound basis for undertaking comprehensive and contextually tailored assessments of climate change impacts and economic vulnerability. The framework can be extended to include a broader range of climate change impacts and the social domain of the human sub-system.  相似文献   

12.
A regional experiment in co-management is underway in the Lower Amazon that is developing the basic policy and institutional elements for an ecosystem-based approach to floodplain management. This initiative grew out of the grassroots movement of floodplain communities who, concerned with excessive commercial fishing pressure on local fisheries, took control of local lakes and implemented collective agreements regulating fishing activity. This paper describes the main elements of the evolving regional management system. This process has focused on four main dimensions of floodplain settlement and resource use: development of sustainable management systems for floodplain resources, policies and institutions for fisheries co-management, collective agreements for grazing cattle on floodplain grasslands, and a land tenure policy consistent with the objectives of the evolving co-management system. Over the last year INCRA, the National Institute for Colonization and Agrarian Reform, has begun implementation of a comprehensive new land tenure policy that could resolve structural deficiencies in the existing co-management system and provide the basis for the ecosystem-based management of the Lower Amazon floodplain. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.  相似文献   

13.
Climate change can cause significant (un)foreseen changes in the fisheries sector. However, adaptation has the potential to moderate some of the impacts. This paper explores the challenges faced by both freshwater and marine fisheries sector in addressing climate change and teases out intervention measures from 21 African countries. The paper uses document analysis and draws selected analysis parameters from the grounded theory. The data are obtained from the United Nations Framework Convention on Climate Change National Communication reports. Among the key adaptation measures emerging from the analysis are: fish breeding, integrated coastal management, putting in place appropriate policies, water and flood management as well as research and development. The study concludes that adaptation in the African fisheries sector should be prioritised, an aspect that could also apply elsewhere in the world to enhance food security.  相似文献   

14.
综合渔获量规模、作业方式结构、作业方式能耗强度和燃油排放系数等因素对温室气体排放的影响,在对2006~2011年海洋捕捞渔业温室气体排放核算和时序分析基础上,利用LMDI方法对温室气体排放进行了因素分解。结果表明:海洋捕捞渔业温室气体排放量呈现出稳定的增长趋势,平均每年温室气体排放量增长2666万t;拖网、刺网两种作业方式产生的温室气体占相应年份海洋捕捞渔业温室气体排放量的比重最大,约占80%,且温室效应最强。渔获量规模效应是驱动我国海洋捕捞渔业温室气体排放的最主要因素。建议通过采取“捕捞配额”或实施较长期的禁渔休渔制度来降低渔获量总量,不仅有利于保护海洋渔业资源,还能减少温室气体排放,也可以通过建立海洋捕捞生态补偿制度的方式来调整作业方式结构向低温室气体排放转变  相似文献   

15.
Overexploitation of living resources severely affects aquatic ecosystems and is among the most serious environmental issues worldwide. Lake Victoria, the second largest fresh water lake in the world, provides food and jobs to almost 30 million people in three African countries and is nowadays facing significant decrease in fish stock due to its unsustainable use. To analyse reasons behind the illegal fishing activities in the Kenyan part of the lake, the survey programme was designed based on a rational choice framework, and data analysis on compliance with fisheries regulatory law was carried out. Selection of explanatory variables to be considered was guided by the “Table of 11”, which is a tool elaborated for the Netherlands’ Ministry of Justice to analyse the regulated community’s behaviour and motivations. Key findings of the study show that existing economic environment and weak enforcement contribute to the low compliance with the fisheries regulations and lead to further degradation of the lake ecosystem.  相似文献   

16.
Climate change and food security: a Sri Lankan perspective   总被引:1,自引:0,他引:1  
There is growing concern in Sri Lanka over the impact of climate change, variability and extreme weather events on food production, food security and livelihoods. The link between climate change and food security has been mostly explored in relation to impacts on crop production or food availability aspects of food security, with little focus on other key dimensions, namely food access and food utilization. This review, based on available literature, adopted a food system approach to gain a wider perspective on food security issues in Sri Lanka. It points to several climate-induced issues posing challenges for food security. These issues include declining agriculture productivity, food loss along supply chains, low livelihood resilience of the rural poor and prevalence of high levels of undernourishment and child malnutrition. Our review suggests that achieving food security necessitates action beyond building climate resilient food production systems to a holistic approach that is able to ensure climate resilience of the entire food system while addressing nutritional concerns arising from impacts of climate change. Therefore, there is a pressing need to work towards a climate-smart agriculture system that will address all dimensions of food security. With the exception of productivity of a few crop species, our review demonstrates the dearth of research into climate change impacts on Sri Lanka’s food system. Further research is required to understand how changes in climate may affect other components of the food system including productivity of a wider range of food crops, livestock and fisheries, and shed light on the causal pathways of climate-induced nutritional insecurity.  相似文献   

17.
The urgency of managing marine resources is based on the fact that half of the world stocks are fully exploited, excluding those stocks that are already depleted. Artisanal fisheries in Brazil, both inland and coastal, are responsible for about half of the country’s catches. Therefore, management of local artisanal fisheries is a necessity that provides an additional benefit, considering the observation that decentralization and the use of local ecological knowledge (LEK) in management have given better results than centralized, top-down management. In this study, a third system of knowledge–based on practice and training–is built from the local and scientific systems of knowledge, and a method to accomplish practical steps in local management is shown. Four elements are considered for the process of linking systems towards management: (1) an understanding of the natural environment of the fishery and on the use of natural resources by locals; (2) the knowledge of the marine area used by fishers, i.e., location of fishing spots for each species; (3) the understanding of fisher behavior, e.g., using tools from optimal foraging theory; and (4) the knowledge fishers have of the biology and ecology of species and their LEK, based on studies of the ethnobiology, ethnoecology, and ethnotaxonomy of fish. Considering the availability of publications on topics 1 and 2, illustrative cases are shown using optimal foraging models in Itaipu Beach, Rio de Janeiro and São Paulo Bagre, Cananéia, São Paulo, and using common snook, Centropomus undecimalis, as an example for a target species. Finally, local programs including training courses using both scientific and local knowledge are proposed within coastal artisanal fisheries.  相似文献   

18.
In Southeast Asia, inland fish resources are crucial for small-scale fishing households. Their decline, due to overfishing and a set of socio-ecological factors, jeopardises aquatic ecosystems and the livelihoods of fishing communities. Singkarak Lake (West Sumatra) exemplifies this sustainability challenge. The paper proposes a multi-disciplinary analysis of the situation. First, it identifies and documents the primary livelihood systems and the strategic adaptations involved in fishing communities. Based upon a sample of 200 households and the implementation of multivariate analyses, a typology is developed. Three household types are identified. Type I comprises better-off farming fishers that have high fishing capitals and income but the lowest returns on fishing and land assets. Type II includes poor fishing farmers with higher farming income; they show the highest return on land assets. Type III is composed of poorer, younger fishers with the highest return on fishing assets and fishing costs. They have little land, low farming income, and diversified livelihood sources. Second, the technical efficiency (TE) of fishing households is studied using a data envelopment analysis. The results show that the average TE is low, but marked differences exist between the types. Type I households have the lowest TE in fishing, confirming an extensification and overcapitalisation strategy. Type II households show a high technical fishing efficiency. They have developed on-farm diversification with a combined, balanced livelihood system. Type III households are the most efficient fishers. They developed an intensification strategy together with off-farm diversification. Different livelihood strategies and economic portfolio have been developed as the response to the limited resources, uncertainty, fluctuating environment and other source of vulnerability. The fishers built up their livelihood based on their assets’ ownership, access to other resource out of fishing and their socio-economic status. In this context, understanding livelihood diversity among small-scale fishers, different socio-economic, their efficiency, constraints and opportunities emerge as important factor in policy formulation to enhance support to small-scale fishing communities and improved management of both the resources and local development. Finally, the paper suggests a focus on people and community-related solutions and proposes a threefold approach of resource conservation, livelihood improvements and restructured governance.  相似文献   

19.
Evaluating the effects of fishing and environmental factors on fish populations are fundamental tenets of fisheries science. In this study, we assess associations between environmental variables (sea surface temperature; North Atlantic Oscillation index; upwelling; wind magnitude; westerly winds; northerly winds; river discharge) and fishing variables (fishing effort) in Diplodus sagus catch rates accounting for regional analyses (northwest coast; southwest coast and Algarve—Algarve south coast). Different time series models for data fitting (multi-model approach) were used. The models were lagged, according to species fishing recruitment age based on the hypothesis that fisheries catches depend on larvae recruitment and survivorship. D. sargus catch rates across areas were unrelated to fishing effort but correlated to environmental variables, with seasonal events explaining much of the variability in trends. On the northwestern coast, the catch rates were mainly set by sea surface temperature (SST) and wind magnitude; however, southwestern coast catch rates were set by NAO winter. On the south coast, only one statistical model (SST, upwelling and westerly winds) associated spring conditions with D. sargus catch rates. The multi-model approach revealed autumn, winter and spring seasonal effects to be related with northwest, southwest and Algarve coastal catch rates, respectively, indicating a possible coastal longitudinal gradient related with given periods of spawning and larval availability. The metadata analysis yielded different results from the regional analyses. In summary, marine resource management should take regional environment characteristics and variability into account when determining sustainable catch rates in given areas for species with high habitat site fidelity.  相似文献   

20.
长江口及邻近水域渔业资源监测现状分析   总被引:1,自引:0,他引:1  
长江口及邻近水域是我国多种重要鱼类产卵、索饵、育肥的优良场所和洄游通道,对于该水域渔业资源进行有效监测是开展资源评估和养护的基础.以渔业资源监测的4种常见途径,即注册制度、问卷调查及访问调查、直接监测和报告制度为框架,对照总结了这一水域各种监测项目的发展水平和缺陷,特别针对依赖于渔业的调查和独立于渔业的调查,详细分析了渔业观察员项目、科考船、采样调查设计、渔业声学调查、标志放流、鱼卵仔稚鱼调查等环节的发展现状.在此基础上对现有监测项目的发展完善提出改进建议,旨在为该水域后续建立科学合理的渔业资源监测体系积累基础参考资料.  相似文献   

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