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1.
《Marine Policy》2014
Marine fisheries support the livelihoods of millions of people worldwide. These fisheries and the communities that depend on them are highly vulnerable to climate change and other interacting anthropogenic threats. The cumulative and interacting effects of these stressors could potentially produce declines in fish production, which would significantly impact artisanal fishers. Assessing relative vulnerability of fishing communities to anthropogenic stressors is an important first step to identifying mitigation or adaptation strategies. This study assessed the vulnerability of 12 coastal communities in the Northern Gulf of California to disruptions in fishing activities from anthropogenic stressors, including climate change. The Northern Gulf is a megadiverse area and a major source of fishery resources. Quantitative indicator indices based on secondary and primary data were developed to assess the three aspects of vulnerability: sensitivity, exposure, and adaptive capacity. The key components of vulnerability varied amongst communities. Vulnerability was higher in communities with higher fishing dependence and lower socioeconomic diversification. The approach presented here provides important insights into the type of policy actions that might be needed in different communities for adaptation and mitigation. 相似文献
2.
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
3.
Coastal erosion and flooding are major threats to coastal dwellers, and the situation is predicted to worsen as a result of the impacts of climate change and associated sea level rise. In order to identify the level of vulnerability of various sections of Ghana's coastline for planning and future hazard management, a coastal vulnerability index approach was adopted for the creation of the relative vulnerability map. The coastal vulnerability variables used include geomorphology, coastal elevation, geology, local subsidence, sea level rise, shoreline change rates, mean tidal range, mean wave height and population density of the coastal areas. Risk factors were assigned to the various variables, and all the factors were combined to calculate the coastal vulnerability for the coastal front of each administrative district along the coast. The outcome was used to produce a vulnerability index map of coastal districts in Ghana. The results revealed that parts of the central coast and the eastern coasts of Ghana were the most vulnerable. It was identified that about 50% of the 540km shoreline of Ghana is vulnerable. This assessment will facilitate the long-term adaptation planning and hazard mitigation to inform the management of Ghana's coast. 相似文献
4.
Expansion of economic activities, urbanisation, increased resource use and population growth are continuously increasing the vulnerability of the coastal zone. This vulnerability is now further raised by the threat of climate change and accelerated sea level rise. The potentially severe impacts force policy-makers to also consider long-term planning for climate change and sea level rise. For reasons of efficiency and effectiveness this long-term planning should be integrated with existing short-term plans, thus creating an Integrated Coastal Zone Management programme.As a starting point for coastal zone management, the assessment of a country's or region's vulnerability to accelerated sea level rise is of utmost importance. The Intergovernmental Panel on Climate Change has developed a common methodology for this purpose. Studies carried out according to this Common Methodology have been compared and combined, from which general conclusions on local, regional and global vulnerability have been drawn, the latter in the form of a Global Vulnerability Assessment.In order to address the challenge of coping with climate change and accelerated sea level rise, it is essential to foresee the possible impacts, and to take precautionary action. Because of the long lead times needed for creating the required technical and institutional infrastructures, such action should be taken in the short term. Furthermore, it should be part of a broader coastal zone management and planning context. This will require a holistic view, shared by the different institutional levels that exist, along which different needs and interests should be balanced. 相似文献
5.
The overall effects of trawling on benthic habitats and their assemblages are dependent on the distribution and intensity of trawl effort. The benthic habitats of the Spencer Gulf prawn trawling grounds are subjected to known variable levels of trawling disturbance recorded from fisher's logbooks. These habitats have not been quantitatively investigated. The aim of the study was firstly to characterise the macro-faunal and -floral assemblages and secondly, to comparatively assess trawl impact by testing the null hypothesis of no differences between five sites exposed to different intensity of trawl effort. The distribution and abundance of benthic macro-fauna and -flora were studied at two sampling resolutions by using beam trawl sampling (10,000 m2) and underwater stereophotography (4.5 m2) at five sites with different levels of trawl disturbance (effort). The results showed that the Spencer Gulf prawn trawling grounds are characterised by sandy sediments with a low content of silt and clay, with the exception of one site with very fine gravel. Biomass, abundance and cover of macro-fauna and -flora were generally low throughout, but with large differences among sites. Biomass, abundance and cover were found to be negatively correlated to both trawl hours from 1994–1998 and during the period of study. ANOSIM and SIMPER analyses using biomass, abundance and percentage cover as variables showed significant differences between sites with eight species or taxonomic groups contributing more than 10% to the observed similarity within sites. The two northern sites were dominated by sponges and the bearded mussel, Trichomya hirsutus, and the southern hammer oyster, Malleus meridianus. Other species that contributed to the similarity within sites were the ascidian, Polycarpa viridis, mobile epifauna (the blue swimmer crab, Portunus pelagicus, and the western king prawn, Penaeus (Melicertus) latisulcatus) and demersal fish species (Degens leatherjacket, Thamnaconus degeni, and the Melbourne silver belly, Parequula melbournensis). Simpson's Index of Diversity (1 − λ) and species richness in the beam trawl samples were fairly even across all sites, but a significant effect of site was found in the stereophotographic transect samples. It was concluded that prawn trawling has a strong influence on the structure of the benthic habitats of the Spencer Gulf prawn fishing grounds highlighted by the magnitude of change and the strength of the gradient of effects. Confounding factors linked to the biophysical attributes of the sites are believed to be minor. 相似文献
6.
《Marine Policy》2013
In Bangladesh, prawn (Macrobrachium rosenbergii) farming remains dependent on the capture of wild postlarvae as hatchery production is still inadequate. However, prawn postlarvae fishing has been accompanied by concerns over recent climate change. Different climatic variables including cyclone, salinity, sea level rise, water temperature, flood, rainfall, and drought have had adverse effects on coastal ecosystem, thus determining a decline in the availability of prawn postlarvae and thereby catch. The households of postlarvae fishers also face a variety of socioeconomic constraints due to climate change. Considering extreme vulnerability to the effects of climate change, an integrated approach needs to be introduced to cope with the challenges. 相似文献
7.
Informing the management of coastal marine habitats at broad spatial scales is difficult because of the costs associated with collecting and analyzing ecological data at that scale. Spatially explicit assessments of the risk to coastal marine habitats from cumulative threats provide an alternative approach by identifying sites that are exposed to multiple anthropogenic threats at broad scales. In this study, qualitative measures of vulnerability were combined with geospatial data to evaluate the risk to coastal seagrasses at the scale of the Great Barrier Reef (GBR) region (∼26,000 km2) of Queensland, Australia. The risk assessment outputs identified agricultural, urban and industrial runoff, and urban and port developments as the major anthropogenic activities threatening coastal seagrasses. ‘Hot spots’ with multiple threat exposure were all in industrial port locations and the southern two-thirds of the GBR. There is a distinct discontinuity in threat exposure along the GBR coast with 98% of seagrass meadows in the northern third exposed to only low levels of anthropogenic risk. The clustering of threat exposure is discussed in terms of coastal management policy. The approach outlined in this study provides management agencies a method of achieving maximum return for minimal investment in data collection at broad spatial scales by identifying sites where management intervention would be best targeted. 相似文献
8.
《Marine Policy》2013
Benefits humans rely on from the ocean – marine ecosystem services – are increasingly vulnerable under future climate. This paper reviews how three valued services have, and will continue to, shift under climate change: (1) capture fisheries, (2) food from aquaculture, and (3) protection from coastal hazards such as storms and sea-level rise. Climate adaptation planning is just beginning for fisheries, aquaculture production, and risk mitigation for coastal erosion and inundation. A few examples are highlighted, showing the promise of considering multiple ecosystem services in developing approaches to adapt to sea-level rise, ocean acidification, and rising sea temperatures.Ecosystem-based adaptation in fisheries and along coastlines and changes in aquaculture practices can improve resilience of species and habitats to future environmental challenges. Opportunities to use market incentives – such as compensation for services or nutrient trading schemes – are relatively untested in marine systems. Relocation of communities in response to rising sea levels illustrates the urgent need to manage human activities and investments in ecosystems to provide a sustainable flow of benefits in the face of future climate change. 相似文献
9.
The vulnerabilities of fishing communities to climate and environmental change represent major issues for the governance of fisheries resources which have a direct effect on human security, livelihoods and rights. This paper explores the dynamics of social-ecological systems in the estuary of the Patos Lagoon in southern Brazil. The paper identifies key factors that increase and/or minimize the vulnerabilities of the fishing communities in this lagoon with the objective of understanding: (a) the degree to which fishing communities are able to build adaptive and learning capacities to minimize/reduce vulnerabilities and maintain their livelihoods; and (b) how and under what circumstances external and internal factors may influence and disrupt the social-ecological resilience in this lagoon system. Results show that fishing communities with a higher degree of self-organization are able to create ways to minimize their vulnerability to adverse climatic conditions. However, only a few communities have developed adaptive mechanisms to cope with the influence of climate on resource abundance and availability. Little external institutional support for small-scale fishing communities, erosion of their traditional resource use systems and decreasing fish stocks in recent decades have all led to a gradual increase in the vulnerability of fishing livelihoods in this lagoon. The uncertainties associated with climate are related to increasing vulnerability and influence the degree of resource conservation and exploitation. The lack of public policies to deal with the impact of climate variability on the livelihoods of fishing communities and the presence of weak institutions in resource governance represent major threats to the social security of fishers in this region. 相似文献
10.
While climate change is expected to affect cetaceans primarily via loss of habitat and changes in prey availability, additional consequences may result from climate-driven shifts in human behaviors and economic activities. For example, increases in shipping, oil and gas exploration and fishing due to the loss of Arctic sea ice are highly likely to exacerbate acoustic disturbance, ship strikes, bycatch and prey depletion for Arctic cetaceans. In the tropics, climate change may result in increased hunting pressure on near-shore dolphins and whales off Asia, Latin America, Africa, and elsewhere as the availability of other marine resources diminishes. This study explores the range of potential consequences to cetaceans worldwide from predicted climate-driven shifts in human behavior, and evaluates the risks to particular species given their geographic ranges and habitat preferences. While concern about impacts of climate change on cetaceans has largely focused on polar species, the analysis presented here suggests tropical coastal and riverine cetaceans such as the Irawaddy dolphin, Indo-Pacific humpback dolphin, and finless porpoise are particularly vulnerable to those aspects of climate change that are mediated by changes in human behavior. Policy recommendations include the following: (1) information about cetacean populations should be incorporated into national, regional and international climate adaptation decisions wherever possible (for example, via GEF-sponsored adaptation initiatives); and (2) human-mediated impacts of climate change should be included in cetacean conservation and management plans, such as the management procedures of the International Whaling Commission (IWC), where possible. Because human responses to climate change are likely to evolve rapidly over the coming years and decades, it is important that local, regional and international cetacean conservation and management plans include regular reviews to allow them to adapt to new information. 相似文献
11.
12.
为改善临高县海岸带生态环境、提升海岸带生态价值及保障海岸带生态安全，文章在实地考察、文献查阅和资料梳理的基础上，概述了当前临高县海岸带面临的典型生态环境问题，分析生态环境退化的主要原因，提出了海岸带保护修复的对策建议。研究结果表明：临高海岸带地区砂质海岸、红树林、珊瑚礁和白蝶贝等面临较严重的海岸侵蚀、生态环境退化和生物资源枯竭等问题；砂质海岸侵蚀主要受海平面上升、风暴潮等自然因素影响，红树林生态系统主要受围海养殖、环境污染影响，珊瑚礁、白蝶贝等海洋生态系统则主要受渔业捕捞、水体污染等人为活动影响；基于海岸生态退化现状及原因分析，提出文澜河口、抱吴港等岸段开展沙滩喂养及生态堤建设，新盈湾、黄龙湾、金牌湾等重点区实施红树林修复，珊瑚礁、白蝶贝保育区加强自然封育、严防人工干扰等建议措施。 相似文献
13.
Quantitative measurement of the response of benthic habitats to impact from towed fishing gears is of great importance to the ecosystem and the long-term management of sustainable fisheries. To date, most studies on the effects of trawling on the benthos have focussed on before/after, control/impact comparative studies. This research has proved important in terms of describing general trends and has identified taxa that suffer high levels of mortality, and habitat types where impact is the greatest. A limitation, however, to this comparative work is the lack of prediction-based methodology and it would be very beneficial to develop a more mechanistic approach that would allow trawling impact on the benthos to be estimated for a wider range of species and habitats. This paper is a first step in this approach and focuses on modelling the physical interaction between gear components and the seabed. In particular the penetration and disturbance to the seabed caused by (i) the roller clump of a twin trawl and (ii) a trawl door, are examined.A finite element (FE) model of the interaction of these components and the seabed is developed using the different soil models and features available within the Abaqus finite element software package. The resulting models are able to predict the penetration depth and sediment displacement associated with each gear component and the predictions are compared with the results obtained during sea trials. The sea trials were undertaken on two sediment types at depths accessible to scientific divers using SCUBA diving techniques who measured and profiled the physical alteration to the seabed following the passage of a roller clump and a trawl door. In addition, drag forces obtained from the sea trials are compared with numerical predictions of the drag related to the soil and the estimated fluid drag. Good agreement between the experimental trials and numerical simulations is found and hence this study provides the basis for investigation of the interaction of other components and sediment types. 相似文献
14.
This research is based on the need to develop methodology for climate change vulnerability assessment in coastal cities. While there have been some studies on the development of methodologies for vulnerability assessment on a national scale, there have been few attempts to develop a method for local vulnerability assessment with application to coastal cities. The objective of this study was to develop a general methodology to assess vulnerability to climate change and to apply it to the metropolitan coastal city of Busan in South Korea. We followed the conceptual framework for assessing climate change vulnerability provided by the Intergovernmental Panel on Climate Change (IPCC), which is composed of climate exposure, sensitivity, and adaptive capacity. Sea level rises of 0.5 m, 1 m, 2 m, and 3 m were considered as the climate exposure. Sensitivity to sea level rise was measured based on the percentage of flooded area calculated using flood simulation with a GIS tool. The population density and the population at age 65 years and over were also included in the calculation of sensitivity index. Sensitivities to heat wave and heavy rainstorm were quantified using the expert opinions from the Delphi survey and information on land use classification. Adaptive capacity was assessed in three sections: economic capability, infrastructure, and institutional capabilities. By combining the adaptive capacity and three different sensitivities, vulnerability to sea level rise (SLR-V), vulnerability to heavy rainstorm (HR-V), and vulnerability to heat wave (HW-V) were separately evaluated in 16 counties of Busan. Using cluster analysis, we could classify four major groups of counties based on SLR-V, HR-V, HW-V, and reported damage cost. For clustered groups, different adaptation strategies were suggested based on the different vulnerability patterns. Application of our methodology to Busan indicated that our methodology is easy to use and provides concrete policy implications when setting up adaptation strategies. The methodology developed in this study could also be used in mainstreaming climate change into Integrated Coastal Management (ICM). 相似文献
15.
气候变化背景下,海平面上升叠加台风—风暴潮、天文大潮等产生的海岸极值水位事件趋多增强,对我国滨海城市社会经济可持发展构成了严重威胁。为认识未来我国滨海城市海岸极值水位危害性（强度和频率）的变化,本文首先采用第五次国际耦合模式比较计划（CMIP5）数据,分析了不同气候情景下（RCP2.6, 4.5, 8.5,简称为RCPs）下,未来不同年代（2030年、2050年和2100年）我国滨海城市沿岸海平面变化幅度;其次,基于沿海验潮站的历史观测资料和文献数据,分析了未来热带气旋强度变化对海岸极值水位的影响;最后,利用皮尔逊Ⅲ型（P-Ⅲ）水文概率曲线方法,预估了不同气候（RCPs）情景下未来不同年代（2030年、2050年和2100年）我国9个滨海城市海岸极值水位重现期的变化。结果表明：（1）在不同气候情景下,我国滨海城市沿海平均海平面均呈现上升趋势,其中,到21世纪末,长三角地区沿海海平面上升幅度最大,上升速度比全国平均高出约30%;（2）热带气旋的强度与台风—风暴潮的增水幅度存在正相关关系。预计到21世纪末,热带气旋的整体强度很可能将增强,热带气旋引发的台风—风暴潮的增水幅度较当前很可能有明显提高。（3）未来我国滨海城市沿海极值水位将有显著增高的趋势,当前极值水位的重现期将明显缩短。到21世纪末,我国滨海城市当前百年一遇的极值水位,重现期几乎都将缩短至20年一遇以下,其中,大连、青岛、上海和厦门等城市海岸极值水位重现期很可能缩短为（或低于）1年一遇。本文虽在一定程度上反映了不同气候情景下海岸洪水危害性的变化,但对于未来热带气旋的变化及其影响的研究尚有待进一步深入。 相似文献
16.
黄海夏季不同取样网具渔获物组成比较分析 总被引：1，自引：1，他引：1
根据 2 0 0 0年夏季双拖渔船和“北斗”号专业调查船对应站位拖网调查资料 ,进行了两种不同取样网具情况下渔获物组成的比较分析 ,结果表明 :渔船的单位扫海面积渔获量、几种重要种类的长度范围、平均个体长度、5 0 %选择长度、重量计优势度均高于“北斗”号 ,而渔获种类数则少于“北斗”号 ,且两者种类组成相似性较低 ,仅为 0 .4 5 8;而且“北斗”号的底层、近底层鱼类和无脊椎类占总渔获量的比例高于渔船 ,这主要是由于渔具的选择作用造成的。结果说明应用渔船针对渔业生产进行的渔业资源监测 ,对带鱼、小黄鱼、鱼等重要生产种类是适合的 ,能够反映其资源量状况 ,但对群落结构、生物多样性等生态系统水平上的研究却存在着明显的不足 相似文献
17.
This study aims to investigate and model driving forces that lead to increased fishing pressure and an altered state of the environment in the coastal areas near Samsun on the Turkish Black Sea coast. We have applied a modified DPSIR model to structure our investigation and analysis and have investigated the drivers that generate fishing pressure in the Samsun fisheries. The overall health of the ecosystem is declining, and there is a consistent trend of deterioration in the condition of the three major species targeted by the trawl fisheries. Although introduced invasive species have brought significant changes to the Black Sea, it is clear that the state of the environment is significantly and negatively affected by the pressure exerted by fisheries. Fishing pressure has to a certain extent been redirected to pelagic trawling as bottom trawling has become less profitable and a rise in catch capacity has levelled off. This reduction is, however, offset by an increase in illegal trawling and dredging by a very rapidly growing sector of multi-purpose small boats, resulting in a considerable increase in the overall accumulated engine power of fishing boats in Samsun during 2000–2005. Fisheries in Samsun, in particular sea snail fisheries, have constituted a frontier of sorts open to the poorer populations of Samsun during the last 20 years, and, thereby, constitute one of the major drivers for fishing pressure. We identify eight drivers of importance for the period 2000–2005. Although the authorities can impact all or most of those drivers, most of them are beyond the scope of conventional ‘fisheries management’. 相似文献
18.
Zhi Ding Fenzhen Su Yanan Chen Ying Liu Xue Feng Wenqiu Hu Fengqin Yan He Li Pujia Yu Xuguang Tang 《海洋学报(英文版)》2023,42(2):163-174
Increasing intense human activities have largely changed the coastal landscape and caused many environmental issues. However, whether human-induced activities could change the coastal land use gradient pattern, an important coastal zonal characteristic along the sea–land direction, remains unclear. Manila Bay was selected as the study area in this work. According to the distance of the land use and land cover(LULC) to the coastline, we clustered the typical coastal land use sequence patterns(CLU... 相似文献
19.
Incidental mortality in fisheries is the main at-sea threat albatrosses are facing nowadays. In this study we used remote sensing techniques to model the degree of spatial overlapping between the Black-browed albatross (Thalassarche melanophris) and Argentine fisheries, assuming this as a proxy of risk for albatrosses. Eleven tags were deployed on albatrosses during the non-breeding seasons 2011 and 2012 in the Patagonian Shelf. Their distribution overlapped to different extents with the two coastal trawl, three offshore trawl and one demersal longline fisheries. The overlap index showed highest values with both coastal fleets, followed by the ice-chilling trawl fleet. These intersections were located in the Argentinean–Uruguayan Common Fishing Zone, in coastal areas of the SE of Buenos Aires province, El Rincón estuary and over the shelf break. The analysis of intersections of focal areas from albatrosses and all fisheries allowed the identification of thirty-four fishing management units (1° by 1° grid within the Argentine EEZ) classified as of medium, high or very high conservation priority. Very high priority units were placed between 35 and 38°S in the external mouth of Rio de la Plata, and between 45 and 47°S in neighboring waters East to the hake fishing closure. Although there were possible biases due to the limited number of tracked birds and the locations where albatrosses were captured and instrumented, the information presented in this study provides a comprehensive picture of important areas of overlapping during winter that could be used by the fishery administration to prioritize conservation actions under limited resource scenarios. 相似文献
20.
《African Journal of Marine Science》2013,35(3):293-301
The abundance of Indo-Pacific bottlenose dolphins Tursiops aduncus off the south-west coast of Mauritius was estimated using capture-mark-recapture modelling. Over the past two decades this population has been subjected to ongoing anthropogenic disturbance in the form of extensive coastal development. Furthermore, daily dolphin tourism, which started in 1998, has rapidly increased in intensity. Identification photographs were collected between April 2008 and June 2010 from dolphins occurring along a 30 km length of coast where a dolphin tourism industry is concentrated. A total of 137 groups were encountered over 229 survey days. Over 5 000 photographs were taken, from which 35 individuals were considered to be sufficiently distinctively marked to use in mark-recapture analyses. The majority (85.7%) were seen more than once and resighting frequencies indicated a resident population. Three newborn calves were recorded during the study. Open population models produced abundance estimates of <100 individuals in the population. These results will be used to make recommendations for the conservation and management of this small, resident population, which is a valuable economic resource for the island but is currently under threat from high levels of human activity. 相似文献