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1.
As worldwide population continues to grow, so does demand for seafood by consumers. With this trend, interest in sustainably certified seafood is also increasing. The Maine lobster fishery is currently considering certification based on the Marine Stewardship Council (MSC) standard for sustainable and well-managed fisheries. Although certification is argued to provide a market-based incentive to improve sustainable fishing practices, it is a costly and time-consuming process, and often imposes additional requirements on fisheries in order to meet certification standards. To evaluate whether the costs of Maine lobster fishery certification are worth the presumed benefits, lobster industry members were interviewed to learn their opinions of MSC certification, seafood consumers were surveyed to understand their attitudes and purchasing preferences related to lobster, and lessons learned from other MSC-certified fisheries were compiled. MSC certification of the Maine lobster fishery could potentially provide benefits to the industry by differentiating Maine lobster and maintaining access to markets that are looking to exclusively source certified fish products. However, certification is unlikely to provide price premiums for the fishermen, and does not necessarily represent to consumers the most desirable aspects of Maine lobster. Certification programs may need to adapt to consumer preferences and market conditions if they are to continue to provide incentives for the sustainable management of fisheries. 相似文献
2.
New Zealand's quota management system (QMS) was implemented in 1986 to address problems caused by a regulated open entry management system in place for the previous two decades. Excess capacity in the inshore fisheries caused several stocks to become depleted and conflicts to intensify between fishing sectors. The allocation of individual transferable quota (ITQ) was viewed as the best way to improve efficiency within the over-capitalised inshore fisheries and provide incentives for developing the deepwater fisheries. The expected benefits of the QMS fit with the political climate at that time, as the government was using market forces to address the deteriorating economy. This article outlines the results of a research project that involved four medium to large-sized, highly vertically integrated New Zealand seafood firms. The purpose of the project was to identify these firms’ sources of competitiveness in export markets and the process the firms used to develop sources of competitiveness, while adapting to rapid and radical changes to the political and business environment and transformation of the fisheries management system. The project's results show that the basis to seafood firm competitiveness is the security of supply to the fisheries resource provided by the QMS and aquaculture legislation. The project also outlines the role that government policies have in sustaining firm- and industry-level competitiveness. This article contributes to the broader discussion on the application of ITQ and other types of long-term access rights to the management of fisheries and does not express the views of the Ministry of Fisheries. 相似文献
3.
Macroalgae are useful organisms to monitor the environmental quality and to detect impacts due to anthropogenic activities. However, it is very important to identify the scales of variation in natural assemblages, particularly for the detection of environmental impacts. Otherwise, changes due to anthropogenic impacts may be confused with differences due to natural temporal variability. Another important task is to determine the appropriate level of taxonomical effort needed to detect changes in the assemblage structure. Many taxonomical surrogates, at higher taxonomic levels than that of species, have been proposed but, the consistence in space and time of the results produced by surrogates with those obtained at specific level should be tested. The objectives of this study are to identify the seasonal patterns of tidepool macroalgal communities using objective procedures and to test the consistence between the patterns obtained considering data at the species level and functional groups. Results showed that the seasonal pattern obtained using functional groups and species was consistent. Tidepool macroalgal assemblages showed a seasonal pattern with significant differences between spring–summer and autumn–winter. This pattern can be explained by changes in environmental variables and the seasonal development of the dominating species. Ulva spp. and the non-indigenous species Grateloupia turuturu were the species responsible for this pattern due to their high seasonality in terms of biomass. Finally, the abundance and species diversity within the corticated functional group was proposed as indicator of environmental impacts due to its relatively constant abundance and its sensitivity to environmental impacts. 相似文献
4.
Coastal areas, and their small-scale fisheries, are important targets for both internal and transboundary migration partly because high mobility is an inherent feature of many artisanal fisheries livelihoods. As climatic changes are forecast to occur, environmental changes may trigger increased flows of migrant fishers. Policies that seek to promote development in ways that do not extensively degrade natural resources will thus have to deal with likely increases in flows of people across administrative boundaries. However, to date little attention has been directed at this issue and little is known about how policies related to coastal resources and development address these issues. This paper addresses this knowledge gap by analyzing policies and legal documents related to coastal resource management and development to examine the extent to which they recognize and integrate fishers' migration in their provisions. Migrant well-being and vulnerabilities are also addressed by examining the extent to which existing policies dealing with socio-economic development and environmental management address migrants and their needs. The analysis shows that policies related to governance of marine resources and coastal development lack an acknowledgment of fishers' migration issues and suggests that this signals an important gap in policy. The implications of this are discussed. The paper also highlights the fact that the invisibility of the issue in policy means that institutions developed to deal with coastal management at the community level may not have sufficient support from legal and policy documents, and may not be developed or equipped to handle the possible conflicts and difficult trade-offs that need to be addressed as a result of current and potentially increasing fishers’ mobility. 相似文献
5.
《Marine Policy》2014
Limits and barriers to adaptation restrict people’s ability to address the negative impacts of climate change or manage risks in a way that maximises their wellbeing. There is a lack of evidence of this on small-scale fishing communities in developing countries. This study identifies and characterises limits and barriers to adaptation of fishing activities to cyclones and examines interactions between them in two fishing communities in Bangladesh, using household questionnaires, oral history interviews, vulnerability matrices and focus group discussions. The limits include physical characteristics of climate and sea like higher frequency and duration of cyclones, and hidden sandbars. Barriers include technologically poor boats, inaccurate weather forecast, poor radio signal, lack of access to credit, low incomes, underestimation of cyclone occurrence, coercion of fishermen by the boat owners and captains, lack of education, skills and livelihood alternatives, unfavourable credit schemes, lack of enforcement of fishing regulations and maritime laws, and lack of access to fish markets. These local and wider scale factors interact in complex ways and constrain completion of fishing trips, coping with cyclones at sea, safe return of boats from sea, timely responses to cyclones and livelihood diversification. The findings indicate a need for further detailed research into the determinants and implications of such limits and barriers, in order to move towards an improved characterisation of adaptation and to identify most suitable means to overcome the limits and barriers. 相似文献
6.
New Zealand fisheries legislation provides commercial fishing rights to holders of individual transferable quota (ITQ). The settlement of fisheries claims against the Crown by Mäori, New Zealand's indigenous people, brought about the transfer of ITQ holdings to Mäori, and an obligation on the Crown to recognise and provide for indigenous (customary) fishing rights over fishing grounds and other areas that have been of special significance to Mäori. Some types of customary fishing areas exclude commercial fishing and could affect recreational fishing. Fisheries legislation requires that regulatory measures be put in place to avoid, remedy or mitigate the adverse effects of fishing. The Government also aims to protect marine biodiversity by having 10% of New Zealand waters in some form of protection by 2010. The legislative processes for protecting the marine environment and establishing customary fishing areas include assessment of effects on fishing rights. This paper explores the conflicts that arise from legislative obligations to uphold the rights of fishers, to sustain fishstocks and to protect the marine environment. The paper concludes that inconsistent legislative obligations and their disparate processes have led to spatial conflicts and a race for the allocation of space. Legislative obligations need to be integrated to maintain a balance between use of fisheries resources and protection of the marine environment. 相似文献
7.
印支运动以后,在现今的南海及其周围存在过2个古海洋,其中晚侏罗世一早白垩世消失于南海北部陆缘区、北巴拉望-礼乐滩-南沙地块以北的古海洋为“中特提斯”,而早第三纪期间消失于南沙地块以南沙捞越一带的古海洋为“古南海”。它们的结束时间和消失的古地理位置完全不同。对它们的正确识别和区分,对目前进行的南海周边地区中一新生代构造演化研究极为重要。对马来半岛、加里曼丹岛中生代岩相古地理资料的整理和分析结果支持如下结论：中特提斯洋的延伸是从苏门答腊的Woyla缝合线,过婆罗洲的Meratus缝合线。然后绕西南婆罗洲地块至加里曼丹岛的西北(Lupar带或者Boyan带),进入南海西南角(南沙-礼乐滩-北巴拉望地块等以北),再接南海北部陆缘区内的中特提斯缝合线。该区中生代海相地层的分布明显受构造演化的控制,整体趋势是向南退缩。印支运动以前、早-中三叠世的海侵广泛分布于古特提斯带及以南地区,涉及华南,中南地块,马来半岛及以南地区;印支运动基本结束了古特提斯带的海侵,因此晚三叠世一早侏罗世的海侵主要限于中特提斯海域及以南地区,如与中特提斯洋相邻的陆域,包括华南的湘赣粤海湾晚三叠世一早侏罗世的海侵、中南半岛东南部早侏罗世的海侵以及新加坡早侏罗世的海相地层。白垩纪海相地层主要分布于中特提斯以南地区,如加里曼丹岛。 相似文献
8.
The dynamics of high molecular weight organic matter in marine systems are influenced by molecular conformation, interactions with surfaces and susceptibility to enzymatic hydrolysis, parameters that are difficult to observe experimentally. Here we use electron paramagnetic resonance spectroscopy (EPR) and spin-labeled (SL-) polysaccharides to monitor the sorption of SL-polysaccharides to natural sediment surfaces and to montmorillonite and to observe decreases in polysaccharide size due to enzymatic hydrolysis. SL-pullulan, SL-xylan and SL-maltoheptaose all sorbed rapidly to muddy sediments but not to sandy sediments. SL-pullulan and SL-maltoheptaose also both sorbed to montmorillonite; however, SL-pullulan reached substantially greater final surface loadings than did SL-maltoheptaose. Using EPR has the advantages of being rapid (spectra can be acquired in 100 seconds), non-destructive and functional in complex media, including sediment slurries, muddy water or other optically opaque samples, permitting investigation of the interactions between biomacromolecules, extracellular enzymes and mineral surfaces in aquatic environments. 相似文献
9.
Cecilie Broms Webjrn Melle 《Deep Sea Research Part II: Topical Studies in Oceanography》2007,54(23-26):2760
Seasonal development of Calanus finmarchicus was studied in relation to the physical environment and phytoplankton bloom dynamics in the Norwegian Sea during eight basin-scale surveys from March to August 1995. Our main objective was to gain new knowledge about the life cycle of C. finmarchicus and its adaptation to the physical and biological environment of the Norwegian Sea. Time of spawning, estimated by temperature-dependent back-calculations from the occurrences of copepodite stage 1 (CIs), varied by water mass and occurred mainly during the phytoplankton pre-bloom and bloom periods. Recruitment to CI of the year's first generation (G1) generally occurred during the bloom and late bloom. The seasonal development of C. finmarchicus was progressively delayed from Coastal to Atlantic and to Arctic water, and from south to north within Atlantic and Arctic waters. This delay was partly linked to the phytoplankton bloom development that followed the same pattern, but development of C. finmarchicus also showed an increasing tendency to lag behind the phytoplankton development in colder waters. This may explain why C. finmarchicus are less successful in colder water. The consumption of nitrate was used as proxy for the seasonal history of phytoplankton development to aid interpretation of the lifecycle of C. finmarchicus. This approach allows us to align phytoplankton bloom and copepod development sequences despite temporal and geographical variation in bloom development, which otherwise tend to cause variability in quasi-synoptic and large-scale data. Two generations of C. finmarchicus were found in southern and northern regions of Coastal Water, and in southern Atlantic Water. In northern Atlantic Water and in Arctic Water, one generation was observed. 相似文献
10.
Abstract. When the Isthmus of Panama emerged as a land bridge, it set the stage for allopatric speciation in the marine fauna. In the present study Pacific and Atlantic populations of three cognate pairs of crabs were used to discern whether physiological divergence has occurred as a result of exposure to different thermal regimes in habitats and in the putative absence of gene flow. Additional comparison was made with Belize and Florida populations of the Atlantic Panama cognate. This was done to test the strength of correlation between physiological divergence and exposure to different thermal regimes in populations that potentially form a common genetic pool. Water temperatures decrease periodically in Pacific Panama and Florida but not in Atlantic Panama or Belize. Physiological divergence in volume and ion regulation was assessed in response to repeated exposure to either control and decreased temperature or to control and increased temperature. Results indicate that exposure to naturally occurring decreased temperatures in habitats has resulted in divergence. This divergence is demonstrated both in enhanced ability to regulate volume at decreased temperature and impaired ability to regulate volume at elevated temperature. 相似文献
11.
Derek V. Ellis 《Marine Georesources & Geotechnology》2013,31(1):51-63
Abstract This article reviews information recently available from existing marine and coastal mining for responses to environmental issues affecting marine mining at different depths. It is particularly but not exclusively concerned with those issues affecting seabed biodiversity impact and recovery. Much information has been gathered in the past 10 years from shallow mining operations for construction aggregate, diamonds, and gold, from coastal mines discharging tailings to shallow and deep water, and from experimental deep mining tests. The responses to issues identified are summarized in a series of eight tables intended to facilitate site-specific consideration. Since impacts can spread widely in the surface mixing layer SML, and can affect the biologically productive euphotic zone, the main issues considered arise from the depth of mining relative to the SML of the sea. Where mining is below the SML, the issue is whether it is environmentally better to bring the extraction products to the surface vessel for processing (and waste discharge), or to process the extraction products as much as possible on the seabed. Responses to the issues need to be site-specific, and dependent on adequate preoperational environmental impact and recovery prediction. For deep tailings disposal from a surface vessel, there are four important environmental unknowns: (1) the possible growth of “marine snow” (bacterial flocs) utilizing the enormous quantities of fine tailings particles (hundreds or thousands of metric tons per day) as nuclei for growth, (2) the possibility that local keystone plankton and nekton species may migrate diurnally down to and beyond the depth of deep discharge and hence be subjected to tailings impact at depth, (3) the burrow-up capability of deep benthos and their ability to survive high rates of tailings deposition, and (4) the pattern and rate of dispersion of a tailings density current through the deep water column from discharge point to seabed. Actions to obtain relevant information in general and site-specifically are suggested. 相似文献
12.
Giovanni Spagnoli 《Marine Georesources & Geotechnology》2017,35(4):578-585
Helical piles present a possible alternative to driven displacement piles in the offshore sector. While this type of pile is used widely in the onshore environment, design methods tend to be highly empirical and there is considerable uncertainty around the bearing resistance and the installation resistance required to install large diameter piles necessary to resist uplift. The paper combines a theoretical model for estimating torque resistance from the literature with a cone penetration test (CPT)-based model originally developed to estimate the axial resistance of helical piles and to predict the installation torque required to install piles in sand. The model appears to be able to capture the general installation behavior of piles across a range of scales and in various sand states. 相似文献
13.
深水地震资料多次波具有能量强、周期长的特点,降低了资料的信噪比,是处理人员面临的首要问题。多次波衰减效果的好坏,直接影响着最终成像效果及后期储层反演结果的真实性。分析深水多次波的类型、成因和特征,并研究各种多次波衰减技术的优缺点和适用性,最终合理组合多方法、分步衰减多次波是关键。以南海A区深水地震资料为例,通过组合优选基于模型的SRME技术和高分辨率Radon技术进行了实际应用,并就出现的剩余多次波给予分析和改进,提出了“三步法”衰减深水多次波,应用后取得了显著的多次波衰减效果。 相似文献
14.
以Landsat TM/OLI卫星影像为数据源,采用面向对象的分类方法对1990、2000、2010和2015年4个时相的海南岛海水池塘养殖信息进行提取,利用景观格局指数和质心迁移模型研究海水池塘养殖的时空变化特征及其对近岸生态环境的影响。结果表明,1990—2015年海南岛海水池塘养殖面积持续增长且区域差异明显;空间上表现为从西南向东北的迁移;养殖区景观格局趋于破碎化;池塘养殖的扩张侵占了红树林等自然湿地,严重破坏了沿岸生态环境。研究表明海南岛的海水养殖业需要合理的规划布局和科学的改造升级。 相似文献
15.
基于WebGIS的海洋科学数据共享平台的分析与设计 总被引：4，自引：1，他引：3
根据国家自然科学基金委青岛海洋科学资料共享服务中心建设的实际情况,从需求分析、系统结构设计、数据建模以及实现技术等几个方面,详细介绍了基于WebGIS的海洋科学数据共享平台建设的思路和方法。在建设过程中,采用用户界面层、业务逻辑层、数据库层的三层架构模式进行系统软件设计,提高了系统的可维护性;运用组件技术进行编码,实现了代码的封装性和可复用性;采用关系型数据库和Netcdf格式相结合来进行数据的存取,解决了海洋数据结构复杂、格式不统一的问题,使查询变得更为方便;利用IDL和ION技术来开发WebGIS,实现了电子海图的漫游、数据查询以及数据统计结果输出。 相似文献
16.
Hsai-Yang Fang 《Marine Georesources & Geotechnology》2003,21(3):155-166
Development of ocean community systems relating to the Taiwan Strait Tunnel (TST) project, with regionalization and multistage approach is proposed. The purposes of these systems are to assist the development of coastal marine lands and harbor facilities and to develop connecting isolated islands into an organized community by means of embankment roadways, tunnels, bridges, ferryboats, and so on. The major aim of such an approach is to develop the isolated abandoned islands into useful land improvement, expand the forest, agriculture, and fishing industries and other resources to generate additional revenue to subsidize some of the cost for building the TST. This article points out the systems' importance, outlines the general procedures, and discusses a possible transportation network connecting islands with land; and the outlines development of the knowledge-based expert system computer program to be applied to the ocean community systems relating to the TST project. 相似文献
17.
Offshore structures are exposed to random wave loading in the ocean environment and hence the probability distribution of their response to wave loading is a minimum requirement for efficient probabilistic analysis of these structures. Due to nonlinearity of Morison wave loading and also due to intermittency of wave loading on members in the splash zone, the response is often non-Gaussian. Part I of this paper was devoted to the development and validation of a new probability model for drag-only responses (i.e. responses due to the drag component of Morison wave loading). This part is devoted to the development and validation of new probability models for both inertia-only and total responses. 相似文献
18.
St Lucia, the largest estuarine lake complex of its type in Africa, is characterised by natural physico-chemical spatial and temporal fluctuations. This estuary functions as an important nursery area making use of a number of different habitat types and associated environmental conditions. The system has been subject to a number of natural episodic events such as cyclonic flooding and cyclical droughts, the most current has persisted since 2001, resulting in almost permanent mouth closure. Furthermore, high levels of evaporation have reduced lake levels and resulted in compartmentalisation of the system for up to several years at a time. St Lucia is sensitive to evaporation and therefore to vast salinity fluctuations and hypersaline conditions. The upper reaches in North Lake are particularly sensitive to drying out and extended hypersaline events. The macrobenthos has been well studied, but no studies have concentrated on the entire system for such an extent of time. Macrobenthic samples were initially collected in 2004, again in 2005 and biannually from 2006 to 2008. This study was part of a larger multidisciplinary programme aimed at determining the effects of long term drought conditions on the ecology of the St Lucia system, and increasing current understanding of the system response to future catastrophic climatic events. Three areas were sampled (North and South Lake and Estuary) at five sites per area, over five years. Data were analysed by representing communities through time series depictions and discriminating sites and sampling periods to test multidimensional relationships. Linkages between biological distribution and selected environmental forcing variables were investigated. The system was found to be highly variable and supporting a large number of different habitats and co-occurring environmental conditions. This variability makes it difficult to discern spatial or temporal patterns in environmental conditions and macrobenthic ecology. However, some level of resilience to wide ranging environmental changes associated with drought is maintained. This study was able to determine that there exists a core of taxa able to persist even under shallow depth conditions and prolonged hypersalinity. These taxa clearly have a self recruiting strategy and are therefore not reliant on mouth opening to re-establish local populations. This finding alone has important bearing for future studies and management of the system under similar adverse conditions. 相似文献
19.
《Marine Policy》2017
Achieving a low-carbon and sustainable economy is a long-term goal that EU aims at achieving in the next few decades: the potential role of bioeconomy is likely to make the difference, and in particular, the EU aquaculture and the seafood processing industry has the potential to contribute substantially to the emergence of bioeconomies (for instance through new – niche - markets for bio-based products such as algae, etc). In this particular framework, understanding how to enhance cleaner and more sustainable consumption patterns is preliminary to the transition towards more equitable and sustainable markets. The present analysis investigates the role of consumers’ attitudes with respect to sustainable attributes (namely food safety and respect of the environment) in order to suggest on their potential role to catalyze the transition toward bioeconomies. Up to date, empirical investigations on this issue are limited to few markets, and studies on aquaculture are particularly scant. The gap is reduced by the present analysis: it has been implemented a survey on fish consumers to investigate how their attitudes toward food safety and environmental issues tend to influence consumption choices, and it is shown that those attitudes are important determinants of consumers choices. Put differently, a cleaner and more sustainable supply chain (i.e through a safer, and environmental friendly product) is likely to enhance consumption of oysters. To the extent that policy makers, producers, and taxpayers are interested in enhancing sustainable bioeconomies, understanding the relevance of attitudes toward food safety and environmental sustainability is an important and pressing goal. The analysis, novel in its application to a high quality product, speaks in this direction and will help understanding how to accelerate the transition to sustainable bioeconomies. 相似文献