An indicator-based adaptive management framework and its development for data-limited fisheries in Belize     

《Marine Policy》2017

Decisions regarding the selection and implementation of management strategies that constrain fishing pressure can be among the most difficult choices that fisheries managers and stakeholders must make. These types of decisions often need to be confronted in a data-limited context, where few if any management measures are currently in place or fisheries are managed independent of adequate scientific advice. This situation can sometimes create a high risk of overfishing and potential loss of economic and social benefits. To address this situation, simple model-free indicator-based frameworks have the potential to be effective decision-making platforms for fisheries where quantitative estimates of biomass and fishing mortality based reference points are lacking. In this paper, a multi-indicator framework is developed that enables decision-makers to proceed with management decisions in data-limited situations. Model-free indicators are calculated using trends in observed data, rather than stock assessment derived estimates of biomass and fishing mortality. The framework developed is adaptive so that adjustments to catch or effort are recursive and can respond to changing environments, socioeconomic conditions, and fishing practices. Using stakeholder-defined objectives as a foundation, indicators and reference points of fishery performance are chosen that can be evaluated easily by undertaking analyses of available data. Indicators from multiple data streams are used so that uncertainty in one indicator can be hedged through careful interpretation and corroboration of information from alternative indicators. During the adaptive management cycle, managers and stakeholders evaluate each indicator against the associated reference points to determine performance measures, interpret the results using scientific and local knowledge, and adjust fishery management tactics accordingly using pre-defined harvest control rules. The framework facilitates the interpretation of situations in which performance measures suggest divergent stock abundance or productivity levels. A case study is presented on this framework's development for conch and lobster fisheries of Belize.  相似文献   

Climate change: Social adaptation strategies for fishermen     

《Marine Policy》2017

As climate change continues to pose a major threat to the well-being of both people and the environment, adaptation to its negative effects has moved to the forefront among occupations that rely on natural resources for their livelihood. As one of the main occupational groups who are dependent on nature, fishermen are expected to experience many new challenges from the changing climate. Though an adequate amount of scientific research on climate change has been carried out, few studies have explored the social circumstances of the issue, particularly in the context of small scale fishermen. This paper aims to address this gap. Aspects such as risks reduction, social relationships, climate change knowledge, alternative skills, involvement in adaptation planning and access to credit are recommended to be considered as these are found to provide synergy for social adaptation, and it is hoped that such recommendation strategies will assist stakeholders in generating and engendering effective adaptation strategies for small-scale fishermen.  相似文献   

The Adaptive Marine Policy (AMP) toolbox: Supporting policy-makers developing adaptive policies in the Mediterranean and Black Sea     

《Marine Policy》2017

Adaptive management is essential to the practical application of the Ecosystem-Based Approach (EBA). Despite there are frequent assertions that adaptive management is being used, evidence on its success is still limited. Indeed, it is difficult to bring the different elements of adaptive management together in a robust way and to choose the appropriate tools to do it. Therefore, it is necessary to provide a practical framework for adaptive policy action, consistent with the EBA. Accordingly, to operationalize the design and implementation of adaptive policies on the basis of the EBA, the Adaptive Marine Policy toolbox has been developed. The objective of the toolbox is to provide policy-makers a practical framework to design and implement adaptive policies. To show the functionality of the toolbox, the guidelines and resources provided within the toolbox have been applied to the marine litter issue in the Mediterranean and Black Sea as an example. The example application has shown that the toolbox is a useful and operational framework to build a science-policy interface according to the EBA. Despite some resources could be missing from the toolbox, they provide a practical and useful starting point to support the application of the different steps and key activities.  相似文献   

自适应卡尔曼滤波在航空重力异常解算的应用研究   总被引：3，自引：1，他引：2       下载免费PDF全文

郑崴  张贵宾 《地球物理学报》2016,59(4):1275-1283

依据航空重力测量基本原理,构建了航空重力异常解算的卡尔曼滤波模型,将新息自适应卡尔曼滤波器(IAE,Innovation based Adaptive Estimation)应用于量测噪声未知的航空重力异常解算.针对IAE滤波器滑动窗口宽度难以准确确定的问题,通过对多个不同滑动窗口新息协方差估计的加权平均,获得改进的IAE滤波器,该IAE滤波器不仅具有量测噪声自适应估计能力,还能实现滑动采样窗口的优化选取.试验结果表明,IAE滤波器可以降低因量测噪声统计信息不明引起的解算误差,改进IAE解算的重力异常误差约为1mGal.  相似文献   

频率慢度域自适应迭代反演算法压制海上倾斜缆鬼波方法及其应用   总被引：1，自引：1，他引：0       下载免费PDF全文

王冲  顾汉明  许自强  方中于  唐永杰  张健男  胡发动 《地球物理学报》2016,59(12):4677-4689

海上倾斜缆采集技术具有多样的陷波特征,通过去鬼波处理可获得宽频数据.针对海水面波浪起伏及缆深误差引起的鬼波延迟时间估计误差以及崎岖海底和目的层深度变化使得鬼波和一次反射波的振幅差异系数随偏移距的变化而难以给定一个固定值的问题,本文推导出频率慢度域中鬼波滤波算子以及自适应迭代反演求解上行波算法,该鬼波滤波算子与不同水平慢度对应的鬼波和一次反射波的振幅差异系数以及鬼波延迟时间有关.并基于计算出的理论下行波与实际下行波之间的平方误差最小理论实现自适应反演迭代最优计算该振幅差异系数和鬼波延迟时间.合成的及某海上采集的倾斜缆数据去鬼波处理结果表明,频率慢度域自适应迭代反演算法能较好地去除海上变深度缆鬼波,能达到拓宽地震记录频带目的.  相似文献   

Community change and evidence for variable warm-water temperature adaptation of corals in Northern Male Atoll,Maldives     

《Marine pollution bulletin》2014,81(1-2):107-113

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基于参考线圈和变步长自适应的磁共振信号噪声压制方法   总被引：2，自引：2，他引：0       下载免费PDF全文

田宝凤  林君  段清明  蒋川东 《地球物理学报》2012,55(7):2462-2472

核磁共振地下水探测仪的灵敏度高,接收到的纳伏级磁共振探测信号极易受到强工频谐波噪声的干扰,导致信号特征参数提取的准确度降低,影响反演解释的水文地质参数结果.为了解决这一难题,基于相关抵消的原理,针对全波磁共振信号,设计带有参考线圈的90°移相自适应噪声抵消系统,理论计算了参考线圈相对于探测线圈的距离,提出变步长LMS算法进行噪声压制.仿真结果表明,在不同的信号强度及不同的信噪比下,当信号与工频谐波干扰频谱不重合时,采用设计的自适应噪声抵消系统和变步长算法,信噪比可以提高到5.94 dB以上,初始振幅、弛豫时间特征参数的拟合误差在2.8%以内;当信号与工频谐波干扰频谱重合时,采用双向自适应滤波算法,信噪比可以达到5dB以上,初始振幅、弛豫时间特征参数的拟合误差在10%以内,可以满足实际应用的要求;实测数据处理进一步证明了方法的有效性.  相似文献   

Reconciling classifications of ecologically and biologically significant areas in the world’s oceans     

Edward J. Gregr  Andrea L. AhrensR. Ian Perry 《Marine Policy》2012,36(3):716-726

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Measuring the benefits and costs of community education and outreach in marine protected areas     

Craig Leisher  Sangeeta Mangubhai  Sebastiaan Hess  Hesti Widodo  Tri Soekirman  Salomina Tjoe  Stevanus Wawiyai  S. Neil Larsen  Lukas Rumetna  A. Halim  M. Sanjayan 《Marine Policy》2012

Conservation organizations often invest considerable resources in education and outreach activities in and around marine protected areas (MPAs). The expectation is that such efforts will change local knowledge, attitudes and ultimately behavior. This is one of the first studies to assess the efficacy of using education and outreach activities to improve community knowledge and attitudes about an MPA. Random sample surveys in 2005 and 2010 (n=1213) before and after education and outreach activities are compared. Program budgets for the same period give the investment levels. With an investment level averaging US$24 per capita/year, the result was an average increase of 33% in “yes” responses across 15 indicators of knowledge and attitudes towards marine conservation. The increase in knowledge and positive attitudes was associated with a large decrease in “not sure” responses, suggesting that community members with fewer initial preconceptions are the most effective target for education and outreach activities. This study demonstrates that investments in MPA education and outreach can generate increases in local knowledge and positive attitudes, and changing knowledge and attitudes is expected to contribute to the long-term compliance with MPA regulations.  相似文献   

HELCOM Baltic Sea Action Plan - A regional programme of measures for the marine environment based on the Ecosystem Approach   总被引：1，自引：0，他引：1  

Hermanni Backer  Juha-Markku Leppänen  Kaj Forsius  Jukka Mehtonen  Minna Pyhälä  Hanna Paulomäki  Tarja Haaranen 《Marine pollution bulletin》2010,60(5):642-649

The Helsinki Commission (HELCOM) Baltic Sea Action Plan, adopted by the coastal countries of the Baltic Sea and the European Community in November 2007, is a regional intergovernmental programme of measures for the protection and management of the marine environment explicitly based on the Ecosystem Approach. The Action Plan is structured around a set of Ecological Objectives used to define indicators and targets, including effect-based nutrient input ceilings, and to monitor implementation. The Action Plan strongly links Baltic marine environmental concerns to important socio-economic fields such as agriculture and fisheries and promotes cross-sectoral tools including marine spatial planning. Due to complementarities with the European Union (EU) Marine Strategy Framework Directive, the Action Plan is in essence a pilot for this process without neglecting the important role of the Russian Federation - the only Baltic coastal country not a member of the EU.  相似文献