适应渔业可持续发展与管理的要求

今年是新世纪的开端，是“十五”计划的第一年，这次渔业专业会议要深入学习领会中央领导同志重要讲话和陈部长的报告，根据中央农村工作会议和全国农业工作会议精神，结合渔业实际来认真思考“十五”发展的基本思路和今年的工作。 在新的形势下，如何适应渔业可持续发展与管理的要求，进一步加强和改善渔业行政管理，应该引起大家的高度关注和深入研究。在市场经济条件下，促进渔业产业结构调整，增加渔民、农民收入，搞好渔业基础设施建设，提高产业素质，加强渔业资源和渔业水域环境的保护，实现渔业可持续发展目标，都需要各级渔业行政…     

Toward sustainable management of small cetacean fisheries around Japan

Abstract:   The management of Japanese domestic fisheries for small cetaceans has been based on a traditional approach that involves only the best set of assumptions and data. However, uncertainty, which is pervasive and inevitable for most fisheries resources, often leads the traditional approach to serious failure. Here is presented the basic framework of a simulation-based approach with a simple Bayesian method that is applicable to Japanese fisheries for small cetaceans. For illustration, the simulation model was applied to Dall's porpoise data in order to investigate the robustness of several management procedures against uncertainty. The simulation showed that the current management procedure, based on only the best values, could fail to manage the stocks at a considerably high probability. However, the use of the conservative management procedure, potential biological removal, permits the sustainable harvesting of Dall's porpoise for at least 100 years into the future, even under uncertainty. In conjunction with a firm structure for implementation of management procedures, the spread of simulation-based approaches will quickly enable successful sustainable management of small cetaceans.     

Towards sustainable fisheries and aquaculture management in the African Great Lakes

Inland fisheries play important roles in food and economic security in the riparian countries surrounding the Great Lakes of Africa. However, the lakes are being systematically degraded by anthropogenic pressures, in combination with the huge population growth prevalent in the region. This paper summarises the outcomes of an international conference to develop a ‘Strategy for Conservation and Sustainable Development of the African Great Lakes Region in a Changing Climate’, held in Uganda in 2017, with particular attention on the potential for fisheries and aquaculture. The paper highlights options for addressing the problems facing the aquatic resources and specifically the importance of effective management of the fisheries and ecosystems of the Great Lakes to achieving the UN Sustainable Development Goals to ensure food and nutritional security and sustainable livelihoods. There is need to improve fisheries assessment and determine the value of the fisheries (and aquaculture). Fisheries legislation, regulation and enforcement need revision and co‐management mechanisms require rethinking. There is considerable potential for aquaculture, and especially cage culture, to increase fish production, but there is an urgent need to address technical, social, environmental and input requirements. It is also imperative that best practices guidelines are developed that will support cage culture production practices.     

Modeling the coastal ecosystem complex: present situation and challenges

To enhance numerical modeling of the coastal ecosystem complex (CEC), we reviewed the CEC and related concepts along with the current coastal ecosystem model framework in this study. We identified two model implementation paths from the initial objectives to numerical models: specific model building, and the use of existing model frameworks. As the CEC is still at the conceptual stage, both paths are possible. Four important ecological features of CEC modeling (population connectivity, habitat heterogeneity, ontogeny of organisms, and trophic interactions) were also identified. Models for population connectivity, species distributions, life histories, and food webs were categorized using these features. We found that some previously established concepts (between–habitat interactions, coastal ecosystem mosaic, and seascape nursery) overlap with the CEC concept. Several existing integrated model frameworks were reviewed, focusing on their potential to simulate CEC processes. Building specific models for the CEC at the current conceptual stage will be challenging, and modification of existing models will be needed if they are to be used for CEC modeling. Habitat function, ontogenetic development in early life stages, and recruitment variability are important factors when modifying existing models for the development of CEC models. Although model complexity should become high to reproduce observed ecoclogical processes, an intermediate level of model ccomplexity is feasible to decrease parameter uncertainty in models for fisheries management.     

Loss of benthic communities: warning signal for coastal ecosystem management

1. Marine managers deal predominantly with shallow coastal waters. These are among the most economically valuable, biologically diverse, and endangered marine ecosystems. 2. Major changes in the composition of biological communities in such shallow seas should be cause for alarm. Changes in the benthic subsystem may provide more information than those in the pelagic subsystem because such changes on the seafloor tend to be more long-term. 3. In the northern Adriatic Sea, soft bottom communities have been subject to a recent series of dramatic mortalities due to oxygen deficiency (accompanied by marine snow events and a series of anthropogenic impacts). The affected areas measure hundreds to thousands of square kilometres. 4. We document this deterioration based on the two major components of soft bottom communities (the endo- and epibenthos), specifically on a key endobenthic species (the sea urchin Schizaster canaliferus) and on a characteristic epibenthic filter-feeding community. 5. The high frequency of disturbances, coupled with lengthy recovery periods, indicate a long-term destabilization of the entire ecosystem. 6. Coastal managers must be aware of the significance of such ecological shifts; biological data should form the basis for policy- and decision-making processes. ©1996 by John Wiley & Sons, Ltd.     

Checking the pulse of the major commercial fisheries of lake Victoria Kenya,for sustainable management

The present study demonstrates the declining state of the major commercial fisheries of Lake Victoria, Kenya, a situation threatening sustainability of the lake's fishery. Data in the present study were derived from resource monitoring programmes that included hydro‐acoustics (2009–2018), trawl net fishing (2011–2018), frame surveys (2000–2016) and catch assessment surveys (2000–2015). The activities provided information on fish stocks and supported advice for fisheries management. The average fish stock densities for Tanzania, Uganda and Kenya of 8.92, 8.25 and 8.19 t/km², respectively, were relatively similar. Diplomatic and sustainable efforts for harmony in fish harvesting among the fishers of the riparian countries are encouraged given the interdependence of the lake. The Kenyan and River Kagera regions had a higher proportion (≈ 4% each) of big‐sized Nile perch (≥50 cm total length) in 2018, signifying the critical breeding areas for Nile perch. To sustain the fishery, there is need to enforce a 36%–44% effort reduction for all the major fisheries, and enforcement of gear limits to avoid harvesting of immature fish and destruction of the lake ecosystem.     

Rapid change in Yangtze fisheries and its implications for global freshwater ecosystem management

Freshwater capture fisheries are globally essential for food security and aquatic biodiversity conservation. The Yangtze River Basin is the third longest and one of the most human‐influenced drainage basins worldwide. Since the founding of P. R. China in 1949, this large river system has suffered increasing human perturbation and its sustainable development is now severely challenged. Meta‐analysis showed that Yangtze River fisheries have experienced an extraordinary process of utilization–over‐exploitation–protection during the past 70 years, to an extent that other globally important rivers may never have encountered. Its fisheries appear to have collapsed over the past four decades, with yield decreasing to only 25% of an historical peak of 400,000 metric tonnes in the late 1950s. Endemic, migratory and rare fishes have been highly threatened with obvious changes in fish community structure and aquatic biodiversity. Anthropogenic activities, including impoundment of water in dams, discharge of pollutants and riverine modification for vessel navigation, have caused large decreases in fisheries yields. Projections from surplus production modelling showed potential for improvement under fishing ban scenarios, but without any prospect for full recovery to historical stock status. This study revealed that the change in fisheries resources was dominated by the social–ecological watershed system, and an integrated approach to river basin management is warranted. Better management of freshwater ecosystems to integrate food security with biodiversity conservation is urgently needed throughout the world, and the changes evident in the Yangtze River fish populations can serve as an informative global reference.     

中华鲟(Acipenser sinensis)生存危机的主因到底是什么?

采用中-大尺度遥感监测手段,对长江流域水域及消落区开展调查与分析,重点阐述长江流域从自然水体为主向人工水面为主的变化趋势,及其对长江流域天然渔业资源衰退的潜在影响。结果显示,近40年全长江流域历史最大水面约63 360 km²,最小水面约26 396 km²,历史最大消落面积约36 964 km²。2019—2020年“一江两湖七河”最大水面约为19 663 km²,最小水面约为14 281 km²,消落区面积6 337 km²,其中反季节性消落区633 km²。2001—2020年和1984—2000年两时段相比,地表水减少水面中超过80% 来自于具有自然水文情势的消落区,而新增水面中,由于水库充填导致的河流水面增加达5 500 km²,致使长江流域水域类型组成结构发生了巨大转变,自然水体占比不足20世纪80年代的一半,而同时期的鱼类资源现存量也下降为20世纪80年代的一半。本研究首次明确反季节性消落区的概念,探讨了长江流域河流梯级水库充填形成的反季节性消落区与鱼类“三场”(产卵场、索饵场和越冬场) 关键栖息地丧失的关系。     

Primary fisheries management: a minimum requirement for provision of sustainable human benefits in small‐scale fisheries

The social and economic importance of small‐scale fisheries is frequently under‐valued, and they are rarely effectively managed. There is now growing consensus on how these fisheries could be managed for sustainability and to minimize the risks of crossing undesirable thresholds. Using a concept developed in health care, these approaches have been referred to as primary fisheries management. By encouraging the use of best‐available information in a precautionary way, the approaches will facilitate sustainable use and should therefore be encouraged, but they accept high scientific and implementation uncertainties as unavoidable because of limited management and enforcement resources and capacity. It is important to recognize that this limitation will result in social costs, because application of a precautionary approach in the face of high uncertainties will require forgoing potential sustainable benefits. Acceptance of primary fisheries management as a final and sufficient goal could therefore add a further constraint on the possibility of fishing communities escaping the poverty trap. Primary fisheries management should be seen as a first and minimum target for fisheries where there is currently no or inadequate management, but the longer‐term goal should still be well informed and adaptive management that strives for optimal benefits, referred to here as tertiary management.     

Changing how we approach fisheries: A first attempt at an operational framework for ecosystem approaches to fisheries management

The increasing need to account for the many factors that influence fish population dynamics, particularly those external to the population, has led to repeated calls for an ecosystem approach to fisheries management (EAFM). Yet systematically and clearly addressing these factors, and hence implementing EAFM, has suffered from a lack of clear operational guidance. Here, we propose 13 main factors (shift in location, migration route or timing, overfishing (three types), decrease in physiology, increase in predation, increase in competition, decrease in prey availability, increase in disease or parasites and a decline in habitat quality or habitat quantity) that can negatively influence fish populations via mechanisms readily observable in ~20 population features. Using these features as part of a diagnostic framework, we develop flow charts that link probable mechanism(s) underlying population change to the most judicious management actions. We then apply the framework for example case studies that have well‐known and documented population dynamics. To our knowledge, this is the first attempt to provide a clearly defined matrix of all the probable responses to the most common factors influencing fish populations, and to examine possible diagnostics simultaneously, comparatively and relatively in an attempt to elucidate the most probable mechanisms responsible. The framework we propose aims to operationalize EAFM, thereby not only better diagnosing factors influencing fish populations, but also suggesting the most appropriate management interventions, and ultimately leading to improved fisheries. We assert the framework proposed should result in both better use of limited analytical and observational resources and more tailored and effective management actions.     

Assessment of a fisheries legal framework for potential development of an ecosystem approach to fisheries management in large rivers

Most small‐scale fisheries of large floodplain rivers are still managed under conventional top‐down regulations that limit the application of an ecosystem approach to fisheries (EAF) due to inappropriate legal frameworks. Using the Parana–Paraguay River fisheries (Argentina) as an example, this study examines the extent to which existing provincial legislations can be prepared for the adoption of an EAF. An Ecosystem Fishing Legal Approach (EFLA) framework is proposed based on different criteria across an environmental–ecological, fishing, social, economic and institutional template. Policy Component Scores (PCS) and an Integrated Policy Legal Index (IPLI) were applied to assess the degree of compliance by current provincial legislations to EAF implementation. Cluster analysis was used to recognise the potential for articulating a legal framework at a basin scale. The EFLA framework, which provided an accurate picture of how provinces were poorly prepared to adopt an EAF for the Paraguay–Parana fisheries, and represents a suitable tool that can be adapted and extended to other basins around the world.     

加强垂钓鱼塘综合管理,促进休闲渔业健康发展

随着渔业生产结构的进一步优化调整,垂钓休闲渔业必将成为广大养殖户提高养殖效益的有效途径.加强垂钓鱼塘的管理和相关配套设施的改善,是垂钓休闲渔业保持快速健康发展非常重要的基础性工作.因此笔者通过近年来对垂钓休闲渔业的长期研究和潜心探索,总结了一些有助于提高垂钓渔业养殖效益的经验,并简要归纳如下,以供交流.     

Using ecological indicators in the context of an ecosystem approach to fisheries for data-limited fisheries

The tenets of ecosystem approach to fisheries (EAF) now occupy centre stage in our efforts to maintain the sustainability of fisheries and rebuild marine ecosystems. The paper discusses how an EAF can be adopted for data limited fisheries and uses the northern South China Sea fishery as an example to demonstrate the selection and use of indicators for determining the states of the fishery and its relevant ecosystem to provide advice on management. Implementing EAF management requires indicators and models that address the impact of fishing across entire ecological communities and determine management actions to be taken to achieve the preset objectives according to decision rules. Data limited fisheries necessarily have limited resources for data collection and scientific studies and therefore could not support complex models. To overcome the data limitation and absence of modelling support, simple indicators have to be used to assess the current state and monitor changes of the fishery and its ecosystem. Such indicators should: (1) be observable and understandable by all stakeholders, (2) be based on easily obtainable and reliable data, (3) adequately reflect the condition of the resource, and (4) have associated reference values and responsive management measures. The paper also reviews the recent development and use of indicators and harvest strategies in both conventional and EAF management to better understand the differences and to shed light on the challenges of EAF, in particular for data limited fisheries.     

保护渔业生态环境,实现渔业可持续发展

现代文明的突飞猛进,人口、资源、环境已成为制约人类生存和发展的三大障碍,对于人口众多、资源相对匮乏、污染严重、土地荒漠化加剧的我国来说,水域资源特别是近300万km2的海洋是实现21世纪经济腾飞目标的坚强后盾。经济的不断发展必然伴随着水域污染。近些年来,通过《环境保护法》《水污染防治法》《海洋环境保护法》的实施,为保护环境提供了法律依据,我国水域环境质量恶化的势头得到了一定程度的控制,但继续恶化的趋势未得到有效的遏制,河流、湖泊、洼淀等内陆水域污染事件时有发生,近岸海洋污染范围不断扩大,赤潮灾害频繁发生,大量生物处于濒临灭绝的危境,不仅给国家、集体、公民造成了严重的经济损失,还危害着人民群众的生命安全。2005年,仅在黄渤海区污染事故面积就达27 998hm2,直接经济损失3.5亿元。1渔业生态环境保护工作的重要性渔业管理的首要任务是重视对渔民利益的保护,渔业生态环境保护是直接保护渔民的利益,是为渔民的生产服务,为渔民的增收服务。通过对渔业水域环境的监管,提高渔业水域质量,增加渔业资源,以实现渔民收入的持续增长。渔业的可持续发展是党中央提出的可持续发展战略的一个组成部分,要让子孙后代有鱼吃,是个战略问题。另外...     

An integrated scheme for the management of drifting fish aggregating devices in tuna purse seine fisheries

Drifting fish aggregating devices (dFADs) are extensively used in modern tuna purse seine fisheries. The use of dFADs has greatly improved fishing efficiency and generated substantial economic returns in purse seine fisheries, but adverse impacts on tuna juveniles, associated species and marine ecosystems are still of concern. Based on an analysis of current challenges in dFAD management measures in tuna regional fishery management organisations (t-RFMOs), we explored opportunities to strengthen dFAD management in tuna fisheries. An integrated dFAD management scheme with multiple tools that account for different usage stages of a dFAD needs to be organised to regulate, track, monitor and recover in tuna purse seine fisheries. We recommend that (1) dFAD-associated definitions should be standardised to provide operational guidance for dFAD activities; (2) all deployed dFADs should be counted towards dFAD limits on active dFADs, except those reported as lost and abandoned; (3) a regional dFAD tracking and monitoring program should track dFAD paths based on daily position reported to RFMOs directly, in addition to mandatory dFAD marking requirements; and (4) a framework of compensation mechanisms should provide financial support for joint dFAD recovery and eco-compensation.     

The relationship between fishing methods, fisheries management and the estimation of maximum sustainable yield

The allocation of effort among fishing gears is as important as controlling effort with respect to both sustainable yield and ecosystem management. Differences in age‐specific vulnerability to the fishing method can modify the maximum sustainable yield (MSY) that is obtainable from a fish stock. Different gears or methods are more or less selective for the species targeted, and MSY is rarely, if ever, attainable simultaneously for all species. The different fishing methods capture different types of nontarget species. Some methods will often be more profitable than others, and different user groups will prefer different methods. In many fisheries, it is unlikely that fishing can be limited to a single gear or method, so compromises among them will be required. Global MSY is discussed as a possible reference point for fisheries management. The yellowfin tuna fishery in the eastern Pacific Ocean (EPO) shows all the above characteristics and is used to illustrate effort allocation among fishing methods.     

Introduction: the coastal ecosystem complex as a unit of structure and function of biological productivity in coastal areas

Coastal seas are composed of relatively independent ecosystems, such as estuaries, rocky shores, mangroves, and coral reefs. Such individual ecosystems (IEs) are linked closely to each other by the dispersal and circulation of nutrients and organic matter and the movement of organisms, and form a coastal ecosystem complex (CEC). The CEC is understood as a unit of structure and function of coastal seas. It is characterized by a high degree of species diversity and it plays a large role in fishery and aquaculture production, as it provides important marine services for humans. This special volume compiles recent ecological studies of target species and IEs, to facilitate the conservation of coastal seas and the sustainability and production of their fisheries and aquaculture based on our understanding of the structure and function of the CEC in these environments.     

A new role for MSY in single-species and ecosystem approaches to fisheries stock assessment and management

In 1977, Peter Larkin published his now‐famous paper, ‘An epitaph for the concept of maximum sustained yield’. Larkin criticized the concept of single‐species maximum sustained yield (MSY) for many reasons, including the possibility that it may not guard against recruitment failure, and the impossibility of maximising sustainable yields for all species simultaneously. However, in recent years, there has been a fundamental change in the perception of the fishing mortality associated with MSY (F_MSY) as a limit to be avoided rather than a target that can routinely be exceeded. The concept of F_MSY as a limit is embodied in several United Nations Food and Agriculture Organization (FAO) agreements and guidelines, and has now been incorporated into the US Magnuson–Stevens Fishery Conservation and Management Act. As a result, the United States now requires the development of overfishing definitions based on biological reference points that treat the F_MSY as a limit reference point and must also define a lower limit on biomass below which rebuilding plans with strict time horizons must be developed. This represents a major paradigm shift from the previously mandated (but often unachieved) objective to simply maintain fishing mortalities at levels below those associated with recruitment overfishing. In many cases, it requires substantial reductions in current fishing mortality levels. Therefore, the necessity of the new paradigm is continually questioned. This paper draws on examples from several fisheries, but specifically focuses on the recent US experience illustrating the practical difficulties of reducing fishing mortality to levels below those corresponding to MSY. However, several studies suggest that even more substantial reductions in fishing mortality may be necessary if ecosystem considerations, such as multispecies interactions, maintenance of biodiversity and genetic diversity, and reduction of bycatch and waste, are taken into account. The pros and cons of moving beyond single‐species assessment and management are discussed. A US plan for improving stock assessments indicates that even a ‘basic’ objective such as ‘adequate baseline monitoring of all managed species’ may be extremely costly. Thus, the suggestion of Larkin (1983, 1997) that the costs of research and management should not exceed 10–20% of the landed value of the catch may preclude comprehensive ecosystem management. More importantly, neither single‐species nor ecosystem‐based fisheries management is likely to improve appreciably unless levels of fishing capacity are aligned with resource productivity, as is currently being promoted by FAO and several individual nations.     

Evolutionary impact assessment: accounting for evolutionary consequences of fishing in an ecosystem approach to fisheries management

Managing fisheries resources to maintain healthy ecosystems is one of the main goals of the ecosystem approach to fisheries (EAF). While a number of international treaties call for the implementation of EAF, there are still gaps in the underlying methodology. One aspect that has received substantial scientific attention recently is fisheries‐induced evolution (FIE). Increasing evidence indicates that intensive fishing has the potential to exert strong directional selection on life‐history traits, behaviour, physiology, and morphology of exploited fish. Of particular concern is that reversing evolutionary responses to fishing can be much more difficult than reversing demographic or phenotypically plastic responses. Furthermore, like climate change, multiple agents cause FIE, with effects accumulating over time. Consequently, FIE may alter the utility derived from fish stocks, which in turn can modify the monetary value living aquatic resources provide to society. Quantifying and predicting the evolutionary effects of fishing is therefore important for both ecological and economic reasons. An important reason this is not happening is the lack of an appropriate assessment framework. We therefore describe the evolutionary impact assessment (EvoIA) as a structured approach for assessing the evolutionary consequences of fishing and evaluating the predicted evolutionary outcomes of alternative management options. EvoIA can contribute to EAF by clarifying how evolution may alter stock properties and ecological relations, support the precautionary approach to fisheries management by addressing a previously overlooked source of uncertainty and risk, and thus contribute to sustainable fisheries.