共查询到20条相似文献，搜索用时 15 毫秒
1.
Jan-Olaf Meynecke Shing Yip Lee Norman C. Duke Jan Warnken 《Estuarine, Coastal and Shelf Science》2006,69(3-4):491
The speculation that climate change may impact on sustainable fish production suggests a need to understand how these effects influence fish catch on a broad scale. With a gross annual value of A$ 2.2 billion, the fishing industry is a significant primary industry in Australia. Many commercially important fish species use estuarine habitats such as mangroves, tidal flats and seagrass beds as nurseries or breeding grounds and have lifecycles correlated to rainfall and temperature patterns. Correlation of catches of mullet (e.g. Mugil cephalus) and barramundi (Lates calcarifer) with rainfall suggests that fisheries may be sensitive to effects of climate change. This work reviews key commercial fish and crustacean species and their link to estuaries and climate parameters. A conceptual model demonstrates ecological and biophysical links of estuarine habitats that influences capture fisheries production. The difficulty involved in explaining the effect of climate change on fisheries arising from the lack of ecological knowledge may be overcome by relating climate parameters with long-term fish catch data. Catch per unit effort (CPUE), rainfall, the Southern Oscillation Index (SOI) and catch time series for specific combinations of climate seasons and regions have been explored and surplus production models applied to Queensland's commercial fish catch data with the program CLIMPROD. Results indicate that up to 30% of Queensland's total fish catch and up to 80% of the barramundi catch variation for specific regions can be explained by rainfall often with a lagged response to rainfall events. Our approach allows an evaluation of the economic consequences of climate parameters on estuarine fisheries, thus highlighting the need to develop forecast models and manage estuaries for future climate change impact by adjusting the quota for climate change sensitive species. Different modelling approaches are discussed with respect to their forecast ability. 相似文献
2.
《Marine Policy》2014
Tropical fisheries are in decline around world as a result of diverse anthropogenic threats. These threats are intimately linked to biodiversity and conservation values because of the heavy dependence of both fisheries and high value marine and coastal wetlands on coastal ecosystem health. Consequently, if the widespread degradation of coastal ecosystems can be halted and remediated, there are substantial benefits to fisheries output, ecosystem resilience, food security, livelihoods, recreation and the protection of ecological assets of national and global significance. The extent, intactness and quality of Australia׳s tropical coastal ecosystems has declined markedly since European settlement, due to the cumulative impact of many small encroachments and local barrier construction on the extent and productivity of coastal wetlands, mangroves and seagrass meadows. Additionally, coastal ecosystem dependent biota has been excluded from large areas of critical habitats. Despite these changes, coastal fisheries show no clear declines that could not be explained by changes in effort. This lack of detectable decline is probably partly attributable to the short history of available fisheries catch data. However, it is also likely that it reflects the offsetting of lost natural productivity by greatly increased anthropogenic nutrient loads; a substantial problem as governments are committed to large scale, long term efforts to reduce discharges of nutrients to coastal waters. This possibility underlines the importance of rejuvenating lost coastal productivity. Evaluation of past remediation efforts show that documented success is rare, due to a complex of factors including ineffective prioritisation, a lack of necessary knowledge and resources, and inefficient monitoring and evaluation. Past experiences from Australia׳s tropics and around the world, together with current ecological understanding, suggests some generally desirable characteristics to enhance the likelihood of successful remediation and repair actions. 相似文献
3.
Sustainability of deep-sea fisheries 总被引：1，自引：0，他引：1
Elliott A. Norse Sandra BrookeWilliam W.L. Cheung Malcolm R. ClarkIvar Ekeland Rainer FroeseKristina M. Gjerde Richard L. HaedrichSelina S. Heppell Telmo Morato Lance E. MorganDaniel Pauly Rashid SumailaReg Watson 《Marine Policy》2012,36(2):307-320
As coastal fisheries around the world have collapsed, industrial fishing has spread seaward and deeper in pursuit of the last economically attractive concentrations of fishable biomass. For a seafood-hungry world depending on the oceans' ecosystem services, it is crucial to know whether deep-sea fisheries can be sustainable.The deep sea is by far the largest but least productive part of the oceans, although in very limited places fish biomass can be very high. Most deep-sea fishes have life histories giving them far less population resilience/productivity than shallow-water fishes, and could be fished sustainably only at very low catch rates if population resilience were the sole consideration. But like old-growth trees and great whales, their biomass makes them tempting targets while their low productivity creates strong economic incentive to liquidate their populations rather than exploiting them sustainably (Clark's Law). Many deep-sea fisheries use bottom trawls, which often have high impacts on nontarget fishes (e.g., sharks) and invertebrates (e.g., corals), and can often proceed only because they receive massive government subsidies. The combination of very low target population productivity, nonselective fishing gear, economics that favor population liquidation and a very weak regulatory regime makes deep-sea fisheries unsustainable with very few exceptions. Rather, deep-sea fisheries more closely resemble mining operations that serially eliminate fishable populations and move on.Instead of mining fish from the least-suitable places on Earth, an ecologically and economically preferable strategy would be rebuilding and sustainably fishing resilient populations in the most suitable places, namely shallower and more productive marine ecosystems that are closer to markets. 相似文献
4.
Most fisheries management studies have concentrated on understanding resource dynamics and have paid less attention to understanding the dynamics of those who use the resources. This situation limits the knowledge about the fisheries system as a whole and specifically about the viability of management schemes. It is vital to understand how the actors within the fishing sector (fishing firm owners/managers, fishers, fisheries managers, and traders) may respond to changes in fishing resources trends, market dynamics, and fisheries policies before they are implemented. These issues are explored in this paper by applying a longitudinal analysis of the Yucatan Mexico's fishing industry. The analysis is presented within the framework of the theory of change and coping strategies. The study primarily involved interviews during 2008 with the main owners of companies in the fishing industry and with fisheries managers and other stakeholders. Time-series catch data on the main fishing resources are also reviewed to evaluate changes across three historical periods and describe how the actors have perceived and responded to those changes. Given conditions of uncertainty in resource availability, changes in market demand and changes in institutional arrangements, the viability of traditional business and resource management practices are discussed. The analysis presents different kind of triggers that have modified the conditions of the fishing sector and had had impacts on the socio-economic–ecological system in which fisheries are embedded. The need for adaptive strategies in the whole chain of the fisheries business and resource management is stressed, given the current changes and conditions of fisheries. The discussion states a series of actions that could improve the relationships between business practices and fisheries management. 相似文献
5.
本研究选取海洋渔业固定资产投资额、海洋渔业劳动力数量、海洋捕捞生产率和海水养殖生产率4个变量,提出影响因素假设;选取我国沿海地区海洋渔业的面板数据,进行模型设定和数据检验。通过确定变截距固定效应的回归模型形式,对模型进行估计和分析,结果表明:海洋渔业固定资产投资额、海洋渔业劳动力数量和海水养殖生产率与海洋渔业经济呈正相关,影响度由大到小依次为劳动力因素、资本因素和生产率因素,而海洋捕捞生产率的影响基本不显著;各地区海洋渔业经济发展程度不一,且差距明显。在此基础上,提出促进我国海洋渔业经济发展的对策建议:加强专业人才集聚;提高资本投入,完善资本市场建设;提高海水养殖生产率,数量和品质兼备;推动区域一体化联动发展。 相似文献
6.
《Ocean & Coastal Management》2003,46(9-10):807-822
Located at the southern Brazilian coast, the Patos Lagoon estuary is bordered by the cities of São José do Norte and Rio Grande, which depend on a series of economic sectors associated with the nearby presence of the estuary and ocean, such as estuarine shrimp fisheries, small-scale ocean fisheries, tourism, port activities and associated industrial activities. Despite its environmental and socioeconomic importance, the Patos Lagoon estuary has suffered severe environmental disturbances mainly over the last three decades. This ongoing trend makes it a priority to develop an Integrated Coastal Management Plan for this area. Recent studies have demonstrated the environmental degradation of several coastal habitats, such as dunes, embayments and salt marshes. Most fisheries have experienced a marked decline, leading to a serious social crisis that has affected approximately 50,000 people directly or indirectly involved in the traditional activity. The growing poverty of small farmers and fishermen has placed increasing demands on local governments, which are struggling to manage conflicts between traditional and non-traditional sectors. This paper describes the objectives, criterions and expected results of an initiative for an ICZM program to be implemented in the estuary, as well as the main difficulties in a context of developing country. 相似文献
7.
Alejandro Espinoza-Tenorio Ileana Espejel Matthias Wolff José Alberto Zepeda-Domínguez 《Marine Policy》2011
Sustainable fisheries take into consideration that managed fisheries ecosystems shift over time in response to evolving environmental as well as market and political factors. These contextual forces are especially valuable in understanding developing countries such as Mexico, where the unconsolidated fisheries administration faces productive marine ecosystems but unsustainable fisheries. To recognize the issues that have inhibited the consolidation of a regulatory system for sustainable fisheries, a contextual factor analysis was applied to the co-development of two current policies in the Mexican fishery regime: fisheries and environmental policies. Six historical phases have been identified in which there are few long periods of stability and frequent short periods of radical change that alternate between stable and adverse contextual situations. These short and contrasting contextual situations cause a kind of tug-of-war in Mexican fisheries policy-making. On the one hand, domestic economic, scientific, and technological forces seem to slowly lead toward the consolidation of sustainable fisheries; on the other hand, domestic policies drift from one position to another at other timing than the international fisheries and environmental policies. Although recent crises seem to highlight new periods of radical change in Mexico, they also provide an opportunity to adopt new structural plans to consolidate domestic forces as a basis for long-term strategies. 相似文献
8.
Cynoscion guatucupa Cuvier 1829 is a migratory pelagic fish species, which has a wide geographical distribution. It is the most important fishing resource for local communities in Bahía Blanca estuary and has been captured by artisanal fishermen since the 1900s. The industrial fleet has been fishing this species in the coastal area of Buenos Aires province since the 1950s, and, since 1970, landings have increased sharply. Between 2000 and 2004, the artisanal fishery in the estuarine waters of Bahía Blanca collapsed. Variations in total landings of the artisanal fleet might have arisen from the environmental variables within the estuary, fishing activity in the surrounding sea region, local pressure within the estuary and/or several other variables. Our results suggest that neither oceanographic parameters nor local pressure seem to have influenced the artisanal fishery of C. guatucupa in the estuarine region. Instead, this fishery seems to have been partially influenced by the increasing fishing pressure exerted by the industrial fishing fleet operating in open waters around the estuary. This study emphasizes the need to take into account fisheries data from both the estuarine environment and the surrounding sea region, particularly when designing management plans for the sustainable use of migrating fish resources. 相似文献
9.
《Marine Policy》2013
Conventional top-down, exogenous approaches to fisheries management have been ineffective in more traditional and small-scale fisheries. Yet, there remains little understanding of the effectiveness of alternative approaches. This case-study of small-scale fisheries in the Comoros examines how effective local fishing associations are at managing common fisheries resources, and provides some understanding of the underlying characteristics of effectiveness. Emphasis is placed on assessing governance effectiveness according to characteristics appropriate within the local context, and on suggesting ways to enhance local institutional strength and capacity to manage resources. Qualitative methods were used to collect data on local governance structures and management tools, fishers’ knowledge and beliefs, and perceptions of the status of fisheries resources in four major fishing villages on the island of Ngazidja. Results show that fisheries management in the Comoros is informally shared between the State fisheries department, a national fishing syndicate, and village fishing associations. Village fishing associations play an active role in fisheries management by collectively designing, monitoring, and enforcing local regulations. Compliance with local regulations is high, primarily due to participatory decision-making, community-monitoring, and strong feelings of solidarity among fishers. Perceptions of the benefits of these regulations are also high. This suggests that by working within these pre-established informal management systems, collective governance of common pool resources can be achieved within communities, and feelings of empowerment and shared responsibility among resource users can lead to effective management practices. 相似文献
10.
入海河口河海分界的若干思考 总被引：3，自引：0，他引：3
河口是河海之间从陆地因素为主向海洋因素为主转化的过渡地区.关于入海河口的河海分界问题,国际上已有法律先例.在法律方面,相关部门对有关法律、法规的理解不同,对河海界限存在不同认识.在自然科学方面,存在着不同的专业强调不同的划界方法的问题;在管理方面,存在着根据各自认为的管理权限提出的河海界限问题.世界各国的海洋管理实践证明,河口属于海岸带综合管理的重要区域.研究河海划分的科学问题,目的是为了管理,但管理不仅依赖于自然科学,同样也依赖于社会科学.河口属于"国家所有",无论哪个政府部门都是代表国家行使管理权利.不管哪个部门,在河口区管理过程中,都必须根据有关法律法规,从严管理,为可持续发展服务.河口管理应该有利于生态系统的维护和保全,坚持以生态系统为基础的管理. 相似文献
11.
The major fisheries on the Pacific coast of Canada can be grouped into 12 species that have consistently represented about 80–90% of the total catch from the past to the present. A review of population dynamics of these species indicates that climate and the ocean environment have a major impact on their productivity. We review the history of Canada's Pacific coast fishery to show that trends in catch were similar to trends in the climate and ocean environment. Decadal scale patterns in climate and the ocean are termed regimes and we show that it is the regime scale of climate variability that most influences the long-term trends in the catches in these major fisheries. Ignoring the impacts of regime shifts on the abundance trends in the future could result in collapses of major fisheries. The difficulty of knowing when a regime shift will occur may be overcome as we discover more about the mechanisms that affect the decadal-scale trends in the rotational velocity of the solid earth which is measured as the length of day (LOD). 相似文献
12.
《Marine Policy》2015
Some of the most important development goals for the countries and territories of the Western and Central Pacific Ocean (WCPO) involve the sustainable management of their fisheries in light of environmental, economic and social uncertainties. The responses of fish populations to variability in the marine environment have implications for decision making processes associated with resource management. There is still considerable uncertainty in estimating the responses of tuna populations to short-to-medium-term variability and longer-term change in the oceanic environment. A workshop was organised to examine how advances in oceanography, fisheries science and fisheries economics could be applied to the tuna fisheries of the WCPO and in doing so identify research priorities to improve understanding relevant to progressing management. Research priorities identified included: (i) improved parameterisation of end to end ecosystem model components, processes and feedbacks through expanded biological observations and incorporation of higher resolution climate models; (ii) development of seasonal and inter-annual forecasting tools enabling management responses to short-term variability in tuna distributions and abundances; (iii) improved understanding of the population dynamics of and the energy transfer efficiencies between food web components; (iv) assessment of the optimal value of access rights and overall fishery value under multiple scenarios of tuna distribution and abundance and influences on decision making by fisheries managers and fleets and (v) development of management strategy evaluation frameworks for utilisation in the implementing and testing of fishery management procedures and to help prioritise research directions and investment. Issues discussed and research priorities identified during the workshop have synergies with other internationally managed fisheries and therefore are applicable to many other fisheries. 相似文献
13.
Snapper (Chrysophrys auratus) is an important coastal fish species in New Zealand for a variety of reasons, but the large amount of research conducted on snapper has not been reviewed. Here, we review life history information and potential threats for snapper in New Zealand. We present information on snapper life history, defining stages (eggs and larvae, juvenile and adult), and assess potential threats and knowledge gaps. Overall we identify six key points: 1. post-settlement snapper are highly associated with certain estuarine habitats that are under threat from land-based stressors. This may serve as a bottleneck for snapper populations; 2. the largest knowledge gaps relate to the eggs and larvae. Additional knowledge may help to anticipate the effects of climate change, which will likely have the greatest influence on these early life stages; 3. ocean acidification, from land-based sources and from climate change, may be an important threat to larval snapper; 4. a greater understanding of population connectivity would improve certainty around the sustainability of fishery exploitation; 5. the collateral effects of fishing are likely to be relevant to fishery productivity, ecosystem integrity and enduser value; 6. our understanding of the interrelationships between snapper and other ecosystem components is still deficient. 相似文献
14.
A two-dimensional steady-state model of light-driven phytoplankton productivity and biomass in partially mixed estuaries has been developed. Effects of variations in river flow, suspended sediment concentration, phytoplankton sinking, self-shading and growth rates on distributions of phytoplankton biomass and productivity are investigated.Numerical simulation experiments show that biomass and productivity are particularly sensitive to variations in suspended sediment concentrations typical of natural river sources and to variations in loss rates assumed to be realistic but poorly known for real systems. Changes in the loss rate term within the range of empirical error (such as from dark bottle incubation experiments) cause phytoplankton biomass to change by a factor of two. In estuaries with adequate light penetration in the water column, it could be an advantage for phytoplankton to sink. Species that sink increase their concentration and form a phytoplankton maximum in a way similar to the formation of the estuarine turbidity maximum. When attenuation is severe, however, sinking species have more difficulty in maintaining their population. 相似文献
15.
Rethinking small-scale fisheries compliance 总被引：3，自引：1，他引：2
Fisheries compliance has been identified as key to sustainable fisheries management. However, it has been widely acknowledged that the approach by many governments worldwide to achieve compliance is largely through law enforcement efforts. Although theories of normative action have expanded compliance thinking from that of rationalist approaches, this paper takes the argument further. By drawing on criminology and security discourse, and on empirical research on small-scale fisheries in South Africa, this paper argues for a new approach to our understanding of compliance. Furthermore, it argues that rather than taking law as given, the formation of law and the power dynamics influencing such processes are critical aspects that need to be acknowledged and understood in fisheries compliance theory. 相似文献
16.
中国主要河口沉积物的重金属地球化学研究 总被引：17，自引：0，他引：17
近年来,河口底质沉积物,不但作为污染物的主要富集介质和重要的生物栖息场所,而且作为比水介质更稳定、更强烈的区域环境质量状态和趋势指示作用的监测要素,日益引起环境界、特别是海洋环境界的普遍兴趣和重视。中国主要河口沉积物的重金属地球化学研究近年来有了长足的进展,获得了诸多成果,这些研究成果为探讨重金属含量的分布、了解其扩散范围和河口环境污染状况等提供了重要的信息。 相似文献
17.
E.N. Shumilin V.V. Anikiev N.A. Goryachev A.P. Kassatkina S.M. Fazlullin 《Marine Chemistry》1993,43(1-4)
The role of biogeochemical barriers as areas of an estuary with dramatically changing gradients of water characteristics in trace metal (TM) migration in the river-sea system, and the influence of physical, chemical, biological factors and corresponding barrier zones on the transport of TM in estuaries is considered. The effects of surface water pH (the Yuriev River — the Okhotsk Sea estuarine system), salinity and biological productivity (the Razdolnaya River — the Japan Sea estuarine system) on the behavior of some metals are demonstrated as the examples of different types of estuarine biogeochemical barriers. 相似文献
18.
Past fisheries development policies in Malaysia are assessed and new grounds for managing the Malaysian fisheries are explored. Some incompatibility in the goals for fishery development are discerned, especially those of increasing domestic landings through mechanization and resource conservation. Future management efforts should be based on a fuller understanding of the fishery stock and regional management of fish stocks. Aquaculture is often seen as a plausible alternative in order to augment supplies from the capture fisheries. A comprehensive multidisciplinary approach is needed to transform and commercialize traditional, experience-dependent culture systems into technology-packaged systems based on scientific methods. There is also substantial potential for the development of recreational fisheries. 相似文献
19.
Fragmentation in high seas fisheries: Preliminary reflections on a global oceans governance approach
《Marine Policy》2017
Notwithstanding the wide range of actions taken to strengthen the legal regime of international fisheries, overexploitation and the risk of depletion of stocks have been strong concerns for decades. Indeed, the regime of international fisheries law is currently not rooted in sustainability, and it does not adequately take into consideration the impact of fishing activities on the wider marine environment. One of the main causes lies in fragmentation of international fisheries law: a lack of coordination between instruments and institutions, and gaps in effective coherent structures for fisheries management. Areas beyond national jurisdiction (ABNJ), including the high seas, are particularly prone to this lack of coordination and integration.One alternative to reach a durable management of high seas fisheries might be found in a ‘global oceans governance approach’. This paper explores how this approach could impact the fragmented regime of fisheries. It suggests that governance-based perspectives underline concepts rooted in adaptability and interactions, concepts that suggest to approach international fisheries law not as a static set of rules but as an evolutive process. Reflecting on an overarching goal of coordination and possible management challenges in ABNJ provides an interesting starting point to develop a comprehensive understanding of the impacts of oceans governance on the fragmented legal regime of high seas fisheries. We now need to see how to give effect to governance, a task that remains, at this point, a work in progress. 相似文献
20.
《Marine Policy》2015
While ocean acidification (OA) poses a significant threat to ocean-related ecosystems and communities reliant on marine fisheries, aquaculture, and coral reef systems, limited public understanding and awareness can prevent coastal regions from being able to adequately assess the need for OA adaptation or mitigation. This study assessed public understanding of OA and how social and demographic factors influence the public’s concern for OA. The analysis was based on 311 questionnaires from full-time Alaska residents. The results showed that most Alaskans self-reported to have a basic awareness of OA, and subsequently were able to recognize that CO2 emissions related to human activity are the dominant driver of changing ocean conditions. However, there was a low recognition of how natural variability in the marine environment affects OA, and most respondents were not very confident in their understanding of OA-related science. Moreover, even though many communities in Alaska are reliant on commercial and subsistence fishing activities, the respondents had a low awareness of fisheries-related OA risk. Given the ongoing debate associated with climate change research, evaluating CO2 mitigation efforts through the perspective of OA could give individuals an unbiased way to assess the pros and cons of more intensive efforts to curb CO2 emissions. Furthermore, using OA communication to enhance the understanding of how natural variability influences OA around the state and the potential economic implications for Alaska fisheries would help residents and stakeholders make informed decisions when considering fisheries management plans, food security, and job diversity as OA intensifies. Solidifying the understanding that any reduction in pH and intensification of OA can have implications for marine species that are irreversible on human timescales will reinforce not only that OA is an immediate concern, but also the importance of taking action now. 相似文献