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人类活动导致臭氧层变薄和混合层变浅，迫使混合层的浮游植物暴露在更高的紫外辐射下。实验以中肋骨条藻（Skeletonema costatum）为研究对象，在自然光照条件下，通过在暗盒上方覆盖不同的截止型滤光板，获得不同波段紫外辐射，探讨不同紫外波段对其生理特性的影响。本实验通过在室外培养，模拟赤潮爆发状态，对中肋骨条藻进行7种不同紫外波段的处理（分别使用280、300、320、340、360、380、400 nm截止型滤光板）。实验结果表明：紫外辐射会显著抑制中肋骨条藻的光合固碳速率，随着紫外波段逐步被滤除，光合固碳速率越来越高；>280 nm和>300 nm波段下的比生长率显著低于>400 nm波段处理；280 nm~300 nm波段紫外对叶绿素a有显著的漂白效应，同时也会显著减少类胡萝卜素的含量；这表明紫外辐射对中肋骨条藻的抑制效应主要是紫外辐射B导致的，而紫外辐射A的作用不显著。在估测浮游植物海洋初级生产力的过程中，紫外辐射的作用往往被忽视。 相似文献
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Catch of marine fish grew from after WW II–1989, at which point it stabilized. In 1996 it began to decline. It continues to decline now, at a time when earth's population is expected to reach 10 billion by 2050. Since the factors driving the increase are primarily the growth in income, population, technology of catching fish and ever increasing fishing effort, it is to be expected that the aggregate marine catch will continue to decline. This decline has important implications for marine ecosystems but primarily its importance relates to the human use of other global resources such as food, water and world's climate. 相似文献
4.
《Marine Policy》2016
This paper surveys the current state and major trends in global fisheries; the environmental and social dimensions of fisheries; and explains how the international community has tried to meet the policy challenges associated with oceans and fisheries. The ocean and the freshwater ecosystems of the world make significant contributions to people's well-being via the many vital social and environmental services they provide (for example, food and nutrition, employment and incomes, carbon cycling and sequestration). The impact that the increase in fishing since the 1950s has had on wild fish stocks, and the significant increase in aquaculture production in the 20th century, have resulted in severe environmental impacts. This has significant effects on marine ecosystems and the health of oceans. The erosion of the resource undermines communities' long-term interests, including food security, employment, and income. Attempts by the global community to address challenges of sustainable production by improving the governance and management of fisheries resources range from national management of fisheries resources, to regional fisheries management organisations (RFMOs) for international fisheries stocks. These attempts have not always successfully met the challenge of balancing current and future use of fisheries. 相似文献
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全球变化对海洋渔业的影响及对策 总被引：2，自引：0，他引：2
人类行为引发的全球性捕捞过度、水体富营养化、气候温暖化和臭氧层被破坏等都地世界渔业产生极大的影响,而捕捞过度使鱼群抵御环境变化的能力降低,并直接破坏渔业资源,从而放大全球变化对海洋渔业的影响。水体富化造成的有害赤潮及鱼虾病害频发、往往给业,尤其是增养殖渔业带来巨大经济损失,温暖化引起的海水升温和盐度改变,不仅直接影响海洋生物的生理、繁殖及时空分布,而且通过对海平面、上升流、厄尔尼诺现象,珊瑚礁、信 相似文献
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The oceans are in trouble. Poorly understood and unprecedented environmental and economic changes are underway in our world's oceans that will significantly affect life in the sea as well as on land. Only in the last thirty years has the contribution of the ocean sector to the economy been measured. An examination of these studies has exposed definitional, conceptual and methodological differences in measuring marine-related economic activity in the economy, making comparisons difficult. Both the ocean and the coastal economies face a world of volatile changes. In the ocean economy marine transport faces unpredictable fuel costs. Coastal tourism also faces losses from climate change impacts and sea level rise. Finally, a warming ocean and increasing acidification of the oceans from greenhouse gases is already affecting coral reefs and a range of fish stocks. Economic measures are important to predict these impacts, as are economic measures of the resilience of different areas of the ocean and coastal economies. This article demonstrates how knowledge of both the ocean, coastal and national economies can help governments address the future impacts and demands posed by nature and human populations on our coasts and oceans. 相似文献
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《Marine Policy》2015
California sea lions (Zalophus californianus) off the coast of Southern California are known to damage both commercial and recreational fishing activities, causing decreases to fish catch and damage to gear. Their increasing population has intensified the potential for conflict between sea lions and anglers, likely requiring changes to current legislation. The recreational fishing community in Southern California is a valuable and largely underutilized source for information and potential solutions to management and legislative problems. This recreational fishing survey-based study conducted in 2013 utilized personal interviews, conducted in the field with recreational anglers and commercial passenger fishing vessel (CPFV) crews in Southern California, to gather data on: (a) the occurrence and impact of sea lion depredation on the local fishing, (b) angler awareness and opinions on current legislation, and (c) the conflict between fishing activities and conservation efforts. Results show that surveyed CPFV operators and private boaters had the most conflict with sea lions and perceive them as more of a problem than anglers on piers, jetties or kayaks. The conflict was also reportedly more prevalent in San Diego County compared to the other counties surveyed (Orange, Los Angeles and Ventura). Participating CPFV operators were overwhelmingly in support of a government culling program for sea lions, while recreational angler respondents did not feel that a control program was necessary. These CPFV operators reported more money lost, and were willing to pay more for an effective deterrent device. There was also a consensus among respondents that fish catch is declining, yet anglers were unsatisfied with the effectiveness of current legislation designed to increase fish stocks. These data will provide a better understanding of California sea lion depredation in Southern California and its effect on recreational anglers in order to aid future mitigation efforts. Additionally, these results provide stakeholder feedback on local marine protected areas and other fisheries management legislation, and build a foundation for future conservation and education programs. 相似文献
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《Marine Policy》2017
Fishing is an important recreational activity for many Australians, with one in every four people participating every year. There are however many different pressures exerted on Australian fish stocks, including climate-related changes that drive changes in local fish abundances. It is inevitable that recreational fishers will need to adapt to these changes. When resource abundance alters substantially, user adaptation to the new situation is required and policies and incentives may need to be developed to encourage behaviour change. It is important to correctly anticipate fisher's response to these policies and incentives as much as possible. Improved understanding of recreational fisher's likely adaptation decisions and the nature and timing of these decisions can help avoid unintended consequences of management decisions. Based on a survey of recreational fishers in the south-east Australian climate hotspot, we identify 4 relevant dimensions to recreational fisher's behavioural adaptation. There are differences in adaptation timing (early, late, and non-adaptors). Non-adaptors are characterised by greater cultural attachment to fishing and stronger perceptions of the factors that influence abundance change. The fisher's preferred adaptation responses and the timing of the behavioural response differs between decreasing versus increasing fish abundance. Insight into perspectives and expectations on how recreational fishers might adapt to changes is useful to develop a set of behavioural incentives that appeal to different groups but remain efficient and effective in their implementation. Such knowledge can create new pathways to achieve meaningful and targeted adaptation responses for different types of recreational fishers. 相似文献
9.
The Norwegian fishing areas extend over various marine ecosystems that will respond differently to climate change. In the North Sea the productivity of the boreal fish species are likely to decrease under global warming and new warm-water species are expected to become more abundant. In the arctic marine ecosystem of the Barents Sea the fish productivity is expected to increase and their distributions expand northward and eastward under global warming increasing the importance of the Russian as well as the Norwegian sectors of the Barents. In the past, decadal-scale climate variations have been shown to strongly influence productivity and distributions of fish stocks. The importance of such shorter-term variations are expected to continue also under global warming. Under global warming the optimum temperature for fish farming along the Norwegian coast will be displaced northwards from the northern part of West Norway towards the Helgeland coast. 相似文献
10.
This article discusses how the Chinese seafood industry will affect the rest of the world's fishing industries. The analysis is based on theories of economic comparative advantage, the international division of labour and the internationalization process related to trade activities. Given the increasing domestic demand for fish in China, the limited availability of domestic fish stocks and less success for farmed marine fish in China are considered some of the most important factors in restricting the growth in Chinese seafood production. The necessity of raw fish imports into China may increase pressure on global fish stocks and international fish prices, resulting in tighter supplies worldwide and higher seafood prices for the Chinese. Sustainable fish harvests and trade require stronger fishery management, in particular in the relations between seafood companies and governments along the entire international value chain supplying China. Such structural changes may allow new value-added possibilities for fish farming and the upgrading of certain fish species for human consumption that were previously utilized purely for fish feed. 相似文献
11.
DR Schiel 《新西兰海洋与淡水研究杂志》2013,47(3):374-391
Abstract This paper reviews interactions involving stands of macroalgae on rocky reefs, and presents new data on changing sea surface temperatures (SSTs), as a contribution to the celebration of the fiftieth anniversary of the Leigh Marine Laboratory (LML) of the University of Auckland. The focus is on trophic interactions involving predators, sea urchins and large brown algae, particularly trophic cascades. Of the 369 publications arising from work at LML, 40 have been on key aspects of these trophic interactions. Quantitative investigations of the structure of kelp bed communities and mechanistic studies involving manipulative field-based experiments, essentially a bottom-up perspective based on habitats and key species, dominated the research through the 1980s. From the mid-1990s onwards, the focus was more on marine reserves and a hierarchical, top-down perspective of community structure, with a particular focus on the role of predatory fish, and marine reserves as a tool of management. I discuss these models of community structure of kelp beds within the wider context of the New Zealand nearshore zone, the varying biogeographic regimes around the coastline, diffuse stressors and the changing nearshore climate. I show there appears to have been a significant warming trend in SST in northeast and northwest New Zealand over the past 30 years. I conclude that a trophic effects model is unlikely to apply to much of the coastline of New Zealand, and that a model involving multiple effects, including bottom-up forces, environmental and climatic influences, species' demographics, and catchment-derived sedimentation is more appropriate for kelp communities over most of the country. New management models are needed to safeguard marine resources and the services they provide. 相似文献
12.
边缘海氮循环过程研究是全球海洋氮循环研究的重要组成部分,对全球氮源汇格局有显著影响,进而对全球气候变化产生反馈。人为活动和气候变化又是影响边缘海关键氮循环过程速率的重要因素。南海作为中国和西北太平洋最大的边缘海,是边缘海氮循环研究的理想场所。本文详细总结了南海近岸和海盆区的氮源汇过程及其内循环过程的最新研究进展,结果显示人为活动对上述过程的显著扰动。此外,全球变暖和海洋酸化正改变不同的氮循环过程速率,并可能引起南海氮收支平衡的不确定性。文章最后提出了边缘海氮循环研究的重要发展方向。 相似文献
13.
Many fish stocks in the world are depleted as a result of overexploitation, which reduces stock productivity and results in loss of potential yields. In this study we analyzed the catch trends and approximate thresholds of sustainable fishing for fished stocks to estimate the potential loss of catch and revenue of global fisheries as a result of overexploitation during the period of 1950–2010 in 14 FAO fishing areas. About 35% of stocks in the global marine ocean have or had suffered from overexploitation at present. The global catch losses amounted to 332.8 million tonnes over 1950–2010, resulting in a direct economic loss of US$298.9 billion(constant 2005 US$).Unsustainable fishing caused substantial potential losses worldwide, especially in the northern hemisphere.Estimated potential losses due to overfishing for different groups of resources showed that the low-value but abundant small-medium pelagics made the largest contribution to the global catch loss, with a weight of 265.0 million tonnes. The geographic expansion of overfishing not only showed serial depletion of world's fishery resources, but also reflected how recent trends towards sustainability can stabilize or reverse catch losses.Reduction of global fishing capacity and changes in fishery management systems are necessary if the long-term sustainability of marine fisheries in the world is to be achieved. 相似文献
14.
Potential climate-change impacts on the Chesapeake Bay 总被引：1，自引：0，他引：1
Raymond G. Najjar Christopher R. Pyke Mary Beth Adams Denise Breitburg Carl Hershner Michael Kemp Robert Howarth Margaret R. Mulholland Michael Paolisso David Secor Kevin Sellner Denice Wardrop Robert Wood 《Estuarine, Coastal and Shelf Science》2010
We review current understanding of the potential impact of climate change on the Chesapeake Bay. Scenarios for CO2 emissions indicate that by the end of the 21st century the Bay region will experience significant changes in climate forcings with respect to historical conditions, including increases in CO2 concentrations, sea level, and water temperature of 50–160%, 0.7–1.6 m, and 2–6 °C, respectively. Also likely are increases in precipitation amount (very likely in the winter and spring), precipitation intensity, intensity of tropical and extratropical cyclones (though their frequency may decrease), and sea-level variability. The greatest uncertainty is associated with changes in annual streamflow, though it is likely that winter and spring flows will increase. Climate change alone will cause the Bay to function very differently in the future. Likely changes include: (1) an increase in coastal flooding and submergence of estuarine wetlands; (2) an increase in salinity variability on many time scales; (3) an increase in harmful algae; (4) an increase in hypoxia; (5) a reduction of eelgrass, the dominant submerged aquatic vegetation in the Bay; and (6) altered interactions among trophic levels, with subtropical fish and shellfish species ultimately being favored in the Bay. The magnitude of these changes is sensitive to the CO2 emission trajectory, so that actions taken now to reduce CO2 emissions will reduce climate impacts on the Bay. Research needs include improved precipitation and streamflow projections for the Bay watershed and whole-system monitoring, modeling, and process studies that can capture the likely non-linear responses of the Chesapeake Bay system to climate variability, climate change, and their interaction with other anthropogenic stressors. 相似文献
15.
全球气候变化影响着海洋生态系统的多个方面,而鱼类群落结构对气候变化的响应机制是探索海洋生态系统演变规律的关键点之一。本文结合国内外相关研究成果,概述了气候变化引起的温度、盐度、CO2浓度、海平面高度、溶解氧以及海流等的改变对鱼类群落结构的影响,并以太平洋十年涛动(Pacific Decadal Oscillation,PDO)和厄尔尼诺−南方涛动(El Niño Southern Oscillation,ENSO)等典型气候现象为例,探讨了鱼类群落对典型气候现象的响应,讨论了需要解决的重点问题,以期为科学应对气候变化和制定海洋生物多样性保护策略提供依据。 相似文献
16.
《Marine Policy》2014
There is increasing concern over the consequences of environmental change for people and communities that depend on already fragile marine resources, given the mounting evidence of sustained over-exploitation and climate change impacts on marine systems. In order to explore the potential social resilience of marine-dependent livelihoods to environmental change, interviews with fishers and marine-based tourism operators in the Caribbean island of Anguilla were undertaken, to identify the impacts of hurricane events on marine livelihoods, the perceptions of resource-users and their potential adaptability to future change. For both sectors of resource-users, there is evidence that they have diversified livelihoods to achieve financial security, which may provide resilience to future climate related impacts or resource variability. In addition, specific behavioural changes that have been developed following previous hurricane events, e.g. removal of fish pots during hurricane months, or bringing boats to shore, indicate fishers' flexibility to changing conditions. However, strong personal and cultural attachment to occupations, particularly among fishers, may hinder resilience. Additionally, the reliance of all of these marine resource-users on the climate-dependent tourism industry may undermine their capacity to cope with future environmental change. Many of these problems are common throughout the Caribbean, as thousands of marine-dependent livelihoods are vulnerable to marine degradation and climate change impacts. Urgent attention is therefore required to support the development of adaptive, sustainable management of marine resources that may enhance resilience to environmental change. 相似文献
17.
文章基于CiteSpace对2000-2020年海洋空间规划研究进行了知识图谱和可视化分析,分析发文量、作者、机构、期刊影响力和合作网络变化,揭示研究热点的变化趋势。研究表明:欧美等经济发达国家和澳大利亚具有较高影响力,国家与机构间合作密切。海洋空间规划研究始终以生态系统和环境保护为中心,研究内容以政策研究和生态环境研究为主,研究热点由关注生态功能转变为以人类活动为主的整体功能规划研究,蓝色经济、蓝色发展是近些年的主要关键词。在海洋开发强度、范围不断增大,全球气候环境频繁变化的背景下,加强海洋观测和数据收集,探索海洋生态系统对环境影响和人类活动响应机制,加强生态模型在海洋应用,细化海洋空间规划管理措施,因海制宜地调整规划方案,实现生态保护和经济发展的齐头并进,是我国海洋空间规划研究的未来方向。 相似文献
18.
《Ocean & Coastal Management》2000,43(8-9):615-655
Almost 50 yr of global multispecies harvests are represented in the FAO capture production database, and offer a broad perspective on events that underlie the major observed changes in global marine harvests. The likely relevance of top–down and bottom–up trophic interactions, versus the impacts of changes in fishing technology and markets on the trophic level of landings, are discussed on a regional basis. Despite the low resolution of this global data set, several common features emerge. Rapid increases in fleet size and technological advance, and imperfect fisheries management measures, are probably responsible for declines in peak multispecies production in many areas since the 1970s, and internal evidence suggests that peak production is not far away in the remainder. Staggered dates of peak landings in different world areas seem to reflect the spread of industrial fishing fleets from `core areas’ to the rest of the world's oceans, which largely took place from the 1960s to 1990s. A general move to higher exploitation of piscivores in global landings is implied in some areas. The hypothesis that top–down removal of predators is affecting lower trophic production is however only one explanation for declining mean trophic levels, and is more likely to emerge from local food web studies. In some regions an increased proportion of short-lived invertebrates in harvests later in the time series supports a move downwards in trophic level targeting. In the North Atlantic and some other areas, fishing down marine food webs may be a likely cause of the increase in landings of shelf planktivores. A shift from depleted apical resources to species lower in the food web may have been made on economic grounds however, independent of possible effects of a release of predatory pressure. Sharp increases in planktivores later in the time series show up in the Eastern Central Atlantic and in the Southeast Pacific and do not appear to be primarily related to depletion of predators. They seem to reflect intermittent strength of upwelling systems, and hence bottom–up effects on food web production, together with changes in harvest technology. For some areas, piscivore landings increased later in the time series than those of planktivores. In the Mediterranean, this seems mainly a bottom–up response to increased marine productivity associated with land run-off and consequent improvements in predatory foraging. In some tropical areas, later increases in piscivorous landings mainly result from expansion of distant water tuna fleets, and are probably unrelated to exploitation of forage fishes. The technological revolution of the 1950s and 1960s involved rapid application of synthetic fibres to improved gear. This led to large-scale mid-water trawling and purse seining by industrial fleets and has especially increased vulnerability of small pelagic stocks over the last few decades. This appears mainly responsible for the apparent decline in mean trophic level of harvests in areas with large stocks of these resources. From an analysis of variances of the sample data set, `Punctuated equilibrium', involving actual changes in ecosystems, rather than just continuous change in the relative harvest rates of species in a given ecosystem, is suggested as an important phenomenon, reflecting both ecological change and changing exploitation strategies. 相似文献
19.
《Marine Policy》2015
This paper outlines the benefits of using the framework for an ecosystem approach to fisheries management (EAFM) for dealing with the inevitable yet unclear impacts of climate change and ocean acidification on coastal fisheries. With a focus on the Asia-Pacific region, it summarizes the projected biological and socio-economic effects of increased emissions of carbon dioxide (CO2) for coastal fisheries and illustrates how all the important dimensions of climate change and ocean acidification can be integrated into the steps involved in the EAFM planning process. The activities required to harness the full potential of an EAFM as an adaptation to climate change and ocean acidification are also described, including: provision of the necessary expertise to inform all stakeholders about the risks to fish habitats, fish stocks and catches due to climate change; promotion of trans-disciplinary collaboration; facilitating the participation of all key stakeholders; monitoring the wider fisheries system for climate impacts; and enhancing resources and capacity to implement an EAFM. By channeling some of the resources available to the Asia-Pacific region to adapt to climate change into an EAFM, developing countries will not only build resilience to the ecological and fisheries effects of climate change, they will also help address the habitat degradation and overfishing presently reducing the productivity of coastal fisheries. 相似文献
20.
Changes in the ventilation rate of the global ocean during the 20th and 21st centuries, as indicated by changes in the distribution of ideal age, are examined in a series of integrations of the Community Climate System Model version 3. The global mean age changes little in the 20th Century relative to pre-industrial conditions, but increases in the 21st Century, by an amount that is independent of the range of climate forcings considered. The increase is primarily due to a decrease in the ventilation rate of Antarctic Bottom Water (AABW), and to a lesser degree, North Atlantic Deep Water (NADW). Changes in a regional volumetric census of age indicate that the changes in AABW are predominantly for waters that are already older than 100 years, so will likely have a moderate direct feedback on oceanic uptake of CO2 and other tracers. On the other hand, the changes in NADW occur most strongly in waters that are a few decades old, so are more likely to have a feedback on the climate system. While the global mean age increases, the age does not increase everywhere in the ocean. Regions newly exposed to strong atmospheric forcing as sea ice retreats experience an increase in convection and decreasing age. Age also decreases over a large volume of the lower thermocline as the rate of upwelling of old deep water decreases with the weakening of the thermohaline circulation. 相似文献