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1.
Large intensity and diversity of human activities result in an increase in complexity in the utilization of space. This paper describes the fisheries and a method to map fishing efforts and catches of different fleets by combining vessel monitoring system (VMS) data and logbook data. The method makes it possible to explore the spatial and temporal variability of fishing and the potential impacts of proposed management measures on the fisheries. The method is proposed to be used in the development of management plans for marine protected areas such as Natura 2000 sites, designated to protect vulnerable habitats and species.  相似文献   

2.
Heino O. Fock   《Marine Policy》2008,32(4):728-739
A method is presented to define principal areas for fisheries at high spatial resolution applicable to be implemented into marine spatial planning procedures. Vessel monitoring system (VMS) data from 2005 to 2006 are acquired to determine vessel-based fishing effort. Principal areas for the German exclusive economic zone (EEZ) are defined as areas in which 75% of the effort of either year is carried out. Examples are given for the 5 most abundant fisheries in the German EEZ in terms of vessel-based effort, i.e. gill netting, pelagic trawling, demersal otter board trawling and beam trawling >300 and <300 HP. A historical comparison for demersal otter board trawling shows relative stability of spatial utilization patterns in the North Sea section of the EEZ.  相似文献   

3.
As catch and effort statistics including fishing time and location are essential for producing abundance indices for utilized fish stocks, fishing states are encouraged under the FAO Code of Conduct for Responsible Fisheries to collect and maintain such statistics. However, for coastal fisheries (including artisanal fisheries) that are mainly composed of small-sized vessels which are usually too numerous to monitor, fisheries statistics collection systems are often either lacking or of insufficient quality (e.g. incomplete or inaccurate). Vessel monitoring system (VMS) data are commonly used to construct or improve estimation of fishing effort and fishing location in large-scale fisheries. Most coastal fisheries lack VMS but their countries do have coastal surveillance radar systems (CSRS) for security and enforcement purposes. This study illustrates and recommends opportunistic use of CSRS data to provide similar scientific benefits to VMS data for coastal fisheries. CSRS in combination with market landings data can construct logbook-like catch and effort statistics. This study introduces a method and demonstrates its usefulness for scientific research and management purposes, including the potential to obtain a higher accuracy and precision, particularly for fishing location and catch amount. Limitations of the CSRS data and challenges to managers involved in its application are also discussed.  相似文献   

4.
A detailed understanding of fishing activity in Scottish waters is required to inform marine spatial planning. Larger fishing vessels are fitted with Vessel Monitoring Systems (VMS) offering spatial information on fishing activity. VMS does not cover smaller vessels (under 15 m), which fish predominantly in inshore waters where the competition for space is often greatest. To improve knowledge of the distribution of fishing activity and value of fisheries in Scotland's inshore waters, Marine Scotland conducted a participatory fisheries mapping project, known as ScotMap. The data were collected during face-to-face interviews with 1090 fishermen of Scottish registered commercial fishing vessels under 15 m in overall length and relate to fishing activity for the period 2007–2011. Interviewees were asked to identify the areas in which they fish, estimate the contribution these areas make to vessel earnings, and to provide associated information. The majority of interviews relate to creel fishing. The data collected were aggregated to provide mapped outputs of the monetary value, relative importance to fishermen and the usage of the seas around Scotland (number of fishing vessels and number of crew). ScotMap outputs provide information on the locations of inshore fishing activities and the economic importance of different sea areas at a much higher spatial resolution than was previously possible. Outputs have informed marine policy development, provide a valuable resource for marine spatial planning in Scotland and illustrate how participatory mapping can generate useful resources on the location and importance of inshore fishing areas.  相似文献   

5.
Vessel monitoring systems (VMS) are considered important instruments for fisheries monitoring, control and surveillance (MCS) to reverse the current depressed state of the world’s fisheries, and have been mandated worldwide by fishery management agencies. The essential function of the system is to provide near-real time vessel position; the potential applications could, however, be more than that. This study explores the additional benefits, with practical examples, that Taiwan has received from implementing the system: in improving the quantity and quality of logbooks recovered, obtaining access to fishery-independent fishing effort estimates and prompt catch/effort reporting, enabling the possibility of regional management and understanding of both fleet dynamics and vessel behavior, and increasing efficiency of vessel safety protection. For other distant-water fishing nations, Taiwan’s experiences serve to demonstrate how the application of VMS technology can advance sustainable fisheries management.  相似文献   

6.
Understanding the economic value of ocean space is critical for implementing marine spatial planning (MSP). Empirical data from 1999 to 2008 are compiled on the economic values arising from commercial fishing in the Gulf of Maine and adjacent areas. The data are analyzed to characterize factors affecting the spatial and temporal distribution of measures of economic productivity and fishing effort. The analysis consisted of four components: (1) estimation of net revenue at the 10-min square level by season and gear; (2) assessment of variability for catch revenue and catch per unit effort; (3) mapping net revenue and variability in the study area; and (4) estimation of interactions among catch, effort, season, and gear type. The results indicated that, at each location, average fishing efforts exhibited a positive response to increases in expected revenues and a negative response to variability in revenues. Most of the variability in catch revenue can be explained by changes in fishing effort, implying that the spatial patterns of fishery resources are relatively stable at the 10-min square level. An important conclusion is that a spatial scale of at least the 10-min square is appropriate for undertaking MSP involving allocations of commercial fisheries.  相似文献   

7.
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8.
2020年6月15日—7月15日,我国首次中国毛虾(Acetes chinensis)限额捕捞试点于江苏连云港实施。本研究提取62艘毛虾网船在限额捕捞期间的421700条北斗船位数据经纬度、航速、航向等信息,运用缓冲区叠加分析法、DBSCAN密度聚类算法、平均中心算法、核密度估计以及数据库查询对捕捞努力量等管控要素进行分析研究。结果显示,所有毛虾网船累计作业239个航次、1942个网次,捕捞过程分为航行、抛锚布网、等待渔获、收渔获、停航等5个状态,中国毛虾捕捞状态船位点呈直线分布,总捕捞时长为4413.73h,82.4%的单网次捕捞时长为1.5—3.5h,各网次捕捞产量呈现多核心空间分布模式,总捕捞努力量为108106343 m~2·h,计算62艘的捕捞总产量值约为2328 t,比上报产量高12.6%;本文通过北斗船位数据解译和提取捕捞努力量以计算中国毛虾捕捞产量及资源空间分布情况,有效应用于中国毛虾限额捕捞,为解决我国单品种限额捕捞难点积累了宝贵经验。  相似文献   

9.
Peruvian anchovy (Engraulis ringens) stock abundance is tightly driven by the high and unpredictable variability of the Humboldt Current Ecosystem. Management of the fishery therefore cannot rely on mid- or long-term management policy alone but needs to be adaptive at relatively short time scales. Regular acoustic surveys are performed on the stock at intervals of 2 to 4 times a year, but there is a need for more time continuous monitoring indicators to ensure that management can respond at suitable time scales. Existing literature suggests that spatially explicit data on the location of fishing activities could be used as a proxy for target stock distribution. Spatially explicit commercial fishing data could therefore guide adaptive management decisions at shorter time scales than is possible through scientific stock surveys. In this study we therefore aim to (1) estimate the position of fishing operations for the entire fleet of Peruvian anchovy purse–seiners using the Peruvian satellite vessel monitoring system (VMS), and (2) quantify the extent to which the distribution of purse–seine sets describes anchovy distribution. To estimate fishing set positions from vessel tracks derived from VMS data we developed a methodology based on artificial neural networks (ANN) trained on a sample of fishing trips with known fishing set positions (exact fishing positions are known for approximately 1.5% of the fleet from an at-sea observer program). The ANN correctly identified 83% of the real fishing sets and largely outperformed comparative linear models. This network is then used to forecast fishing operations for those trips where no observers were onboard. To quantify the extent to which fishing set distribution was correlated to stock distribution we compared three metrics describing features of the distributions (the mean distance to the coast, the total area of distribution, and a clustering index) for concomitant acoustic survey observations and fishing set positions identified from VMS. For two of these metrics (mean distance to the coast and clustering index), fishing and survey data were significantly correlated. We conclude that the location of purse–seine fishing sets yields significant and valuable information on the distribution of the Peruvian anchovy stock and ultimately on its vulnerability to the fishery. For example, a high concentration of sets in the near coastal zone could potentially be used as a warning signal of high levels of stock vulnerability and trigger appropriate management measures aimed at reducing fishing effort.  相似文献   

10.
船位监控系统（vessel monitoring system,VMS）数据在渔船作业特征挖掘分析方面已有较多应用。本文以粤渔10000/10011双拖渔船2017年8月16日—9月16日的VMS数据为例,详细分析了该双拖渔船的作业状态,研究了航次和网次提取方法,并对捕捞强度的空间分布进行了分析。研究结果表明,粤渔10000/10011有4个航速区间,分别为<1.0 m/s、1.0~1.8 m/s、1.8~2.9 m/s和>2.9 m/s,对应渔船的抛锚和慢速、夜间拖网航速、白天拖网航速和巡航状态;2017年8月16日—9月16日期间,粤渔10000/10011共进行了5个航次19个网次的拖网作业,其捕捞强度空间分布呈现近岸海域高离岸海域低的特征,且夜间拖网主要在离岸海域,白天拖网会转移到水深相对浅的近岸海域。  相似文献   

11.
The California Commercial Passenger Fishing Vessel (CPFV) fleet is unique in scale of operation, extensive fishing history, and economic impacts. The basses (Paralabrax sp.), which represent a principal target for the CPFV fleet, recently gained more stringent size limits and bag limits. The goal of this study was to conduct a survey of CPFV captains to assess perceptions regarding the status of two Paralabrax species, as well as the impacts of the new regulations. Catch and effort estimates were also obtained using CPFV logbook data to compare captains’ perceptions with actual changes in the fishery. The captains agreed that both species are vital to recreational fishing, and that the Barred Sand Bass stock is less healthy than Kelp Bass. Catch and effort analyses were consistent with this perception, with more dramatic declines in CPUE exhibited by Barred Sand Bass. The most experienced captains perceived the status of each species to be in a less healthy state than the less experienced captains, suggesting that shifting baselines are occurring. Most of the captains thought the increased minimum size limits had the greatest short-term impact on the fishing experience. The CPFV logbook data summaries support this assertion, but Kelp Bass CPUE showed a trend reversal. In contrast, Barred Sand Bass CPUE has precipitously declined, and spawning aggregations have been absent since 2013. The agreement between captains’ perceptions and logbook analyses strengthens the overall findings, and suggests captains are a valuable resource for informing fisheries management, especially in future studies with data-limited stocks.  相似文献   

12.
Information on the cost of fishing is integral in measuring fisheries performance and correctly evaluating the economic impacts of fisheries regulations and management rules. However, limited availability of cost data often renders such analyses either incomplete or implausible. This study discusses a survey effort that was undertaken in the Northeast US to collect fisheries annual fixed cost data directly from commercial fishermen. Stratified random samples of fishing vessel owners were surveyed in 2012 and 2013. An overview of the survey procedures, sample selection and administration is given here. The data cleaning process, non-response bias and data summaries are also presented. A modeling framework is discussed for estimating fisheries cost data. Robust cost models in combination with regular data collection efforts will allow for more complete economic and financial analyses relevant to fisheries management and conservation.  相似文献   

13.
The assessment of fishing effort is a vital part of fisheries management. However, assessing fishing effort by small-scale local fleets is often problematic, partly because of the complex socio-economic and cultural factors that govern the labour patterns of different fisheries employing different fishing practices. Often, official statistics produced by governmental agencies do not fully capture these factors, so a more holistic understanding of regional fisheries is required. Some contribution by social anthropologists is thus called for, in order to assess actual fishing effort and the trend of regional changes in fishing activities.  相似文献   

14.
Commercial fishing data were used to reconstruct historical spatio-temporal patterns of fishing effort and landings in the bottom longline fishery of the Azores. Key events during an important 15-year period were charted, through fisher interviews together with GIS analysis. While effort distribution varied over time, the prevailing pattern was a shift in focus from eastern to western areas and from shelf/slope to offshore banks and seamounts in response to policy measures (e.g. banning bottom longline inside 3 NM, public aids for modernization of the fleet) and reduced fishing yields. Areas 12–50 NM from shore represented the most vital fishing grounds in terms of fishing effort and production. Declining landings of the major demersal species, in recent years, indicate that present catch levels are not sustainable and further measures need to be taken in order to sustain fisheries resources. Knowledge of fleet behavior and the distribution of fishing effort, particularly in patchy environments, provide valuable insights into the impacts of past management decisions and help predict the outcome of new policies both in this region and elsewhere.  相似文献   

15.
《Marine Policy》2002,26(1):13-34
The organisation of a fisheries statistical system dictates the potential usage of its information output. Information is used for planning of food production (fish as a commodity), for fisheries management (fish as a renewable natural resource), and for nature conservation (fish as an indicator for ecosystem quality). In this sequence, the required temporal, spatial and categorical resolution of data increases, while aggregation into meaningful ecological spaces requires a subtle way of organising the data flow. The effective usage of the present fisheries information of Vietnam is constrained by (1) its low categorical resolution and (2) the non-transparent aggregation of data into mere administrative spaces. Information requirements can be better articulated with the instalment of mandatory evaluation procedures at all levels in the fisheries administration. Our examples range from the national administration of the 4 million ton marine fisheries in Hanoi, to the local administration of a fishing commune in the Red River Delta.  相似文献   

16.
Assessment of IUU fishing for Southern Bluefin Tuna   总被引：1，自引：0，他引：1  
Illegal, unreported and unregulated (IUU) fishing is recognized as one of the largest threats to the sustainability of the world's fisheries. This paper focuses on IUU fishing in the context of unreported catches by members or co-operating non-members of regional fisheries management organizations (RFMOs) and their implications for scientific assessments of stock status and management advice. A review of Japanese market statistics was undertaken in 2006 by an independent panel in relation to catches of southern bluefin tuna (SBT). Based on this review, the Commission for the Conservation of Southern Bluefin Tuna (CCSBT) concluded that very substantial and continuous unreported catches of SBT had been taken by longline vessels since at least the early 1990s. While uncertainty exists about the fleets contributing to these IUU catches, the assumption used within the CCSBT Scientific Committee is that a significant proportion of these were taken by Japanese longliners. Implications of these unreported catches for the stock assessments by RFMOs are discussed in light of the central role that Japanese vessel reported data have in the assessment of the world's tuna and billfish stocks. Results indicate that it is plausible that the unreported catches of SBT stem from the misreporting of catches as other tuna species and/or the location of fishing effort. The magnitude and extended period of the unreported SBT catches highlight the wide-spread risks of relying on fishery dependent logbook data in the absence of verification. An urgent need exists for minimum standards of verification of catch, effort and landing statistics for use in scientific assessments. The fisheries science community needs to be more pro-active in the development of such standards and the implementation of independent monitoring and verification. In addition, there is a need to reform the operation of the scientific bodies of RFMOs in terms of transparency, the treatment of uncertainty and the burden of proof if they are to be effective in providing objective scientific advice consistent with the intent of international agreements.  相似文献   

17.
This paper shows how post-oil spill management measures can affect the general pattern of fishing effort exerted on two particular species of great commercial value in northern Spanish fisheries: anglerfish (Lophius piscatorius and Lophius budegassa) and mackerel (Scomber scombrus). Data time series of catches and fishing efforts were analysed corresponding to the area and time period affected by the oil spill fishing restrictions (December 2002–June 2003) and similar previous and post-spill periods. This was done to detect shifts that could be due to either the oil spill per se or the management measures taken to minimise pollution effects. Then, analyses and simulations with Arcview GIS module FAST (Fishing Activity Simulation Tool v. 1.1) were carried out with the aim of studying the fishing effort spatial distribution. Changes were observed in the Catch Per Unit Effort (CPUE) of anglerfish and mackerel by area or fishery unit. Results show a spatial displacement of fishing effort to other fishing areas in the case of anglerfish, and the transfer of fishing effort between different fishery units in the case of mackerel. Although both effects were caused primarily by the management measures in force after the oil spill, they are considered side or collateral effects. The management measures that have to be taken after any disaster should also consider these kinds of ancillary effects as well as evaluating the likely positive or negative impact of these side effects.  相似文献   

18.
Coastal fisheries are complex ecological and social systems, evolving in time with a shift from commercial towards recreational effort. We describe the coastal fisheries of Mallorca (W Mediterranean) and the management policies implemented to show the challenges faced at regional level to handle the different management tools used to conserve biodiversity and the social fabric in the coastal zone. Our example provides evidence of the complexity of fishing rights and how they can be adapted into practical fisheries management by combining fishing rights, open access recreational fishery, community-based management and biodiversity conservation.  相似文献   

19.
中西太平洋是全球主要的鲣鱼（Katsuwonus pelamis）围网作业渔场,渔场极易受到海洋环境的影响,但渔场分布在众多岛国的管辖海域,如何科学指导企业准确入渔是重要的研究课题。本文根据1995-2012年中西太平洋鲣鱼围网捕捞生产统计数据,选取产量最高的22个海区（5°×5°）,结合Niño3.4区海表温度距平值（SSTA）和作业海域表温（SST）,研究中西太平洋鲣鱼围网渔场的空间分布规律,同时,以各海区捕捞努力量（作业次数）所占的百分比为入渔指标,建立基于环境因子的入渔决策模型。研究认为,中西太平洋鲣鱼捕捞努力量在纬度方向上主要分布于5°S~5°N,其累计捕捞努力量占所有作业海区的87.4%,其中以130°~140°E经度范围为最高,其捕捞努力量占22个海区的45.08%。入渔指标与Niño3.4区的SSTA、作业海域SST均符合正态模型（P<0.01）,Niño3.4区的SSTA最适值为0.25℃,作业海域SST最适值在29.5℃左右。对预测和实际排名前十的海域进行统计发现,预测值与实际值基本一致。研究认为,所建立的入渔预测模型可有效指导企业的渔业生产,为提高企业生产效率提供支撑。  相似文献   

20.
Tropical small-scale fisheries are highly heterogeneous with respect to a wide range of fisheries characteristics, but that heterogeneity has generally not been adequately studied or considered in management. This study investigated fisheries heterogeneity and the extent to which it is accounted for in management regulations in eight small-scale fishing communities located in floodplain ecosystems of the Amazon basin. Analyses of 29,844 fishery landing interview data revealed that fisheries heterogeneity with respect to gear, habitat, species composition, and total catch and fishing effort was high across all communities, but low over the years in the same communities, indicating that each community must be considered as a distinct management unit. Data analyses also revealed that many important community fisheries characteristics were not accounted for by government- and community-based management regulations. Total catch and fishing effort were largely unregulated; there were no size or closed season limits for one-third of the most important fishery species; and the nursery habitats used by most fishery species were not protected in any fashion. Clearly, increased attention to cross-community fisheries heterogeneity can improve the design and implementation of management regulations. The management problems created by the heterogeneity of small-scale fisheries are discussed, and the potential of the “barefoot ecologist” concept to address them is considered.  相似文献   

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