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51.
基于《物权法》的中国捕捞权保护制度的探索   总被引:1,自引:1,他引:0  
唐议  王晓磊  马毅 《水产学报》2011,35(10):1589-1594
《物权法》明确了捕捞权和养殖权的用益物权属性,并规定其受法律保护。但依据我国现有渔业法律制度,实施《物权法》有关保护捕捞权的法律规定还存在一定困难。通过比较分析《物权法》和《渔业法》及相关法规对捕捞权的规定,考察造成捕捞权损害的主要原因,提出了我国捕捞权保护制度的路径选择:(1) 将近岸海洋渔场和内陆水域渔场按县级或县级以下基层行政区域进行划分,确定给所属区域内的传统捕捞渔民专属使用,从而明确捕捞权主体和客体,为建立捕捞权保护制度提供基础。(2) 建立捕捞权损害评估体系,制定捕捞权损害赔偿、补偿标准,规范捕捞权损害赔偿、补偿程序,健全和完善捕捞权损害赔偿、补偿制度。  相似文献   
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53.
拖网作业过程中的网位、网身状态、拖网整体状态是评价拖网性能优劣的重要指标。以南极磷虾拖网为例,通过测量拖网不同部位(上纲、第3~4节网身连接处和网囊口上部中点)深度,以部位间深度差表示拖网作业状态,分析捕捞操作、海洋环境和渔获量对拖网作业状态的影响,确定中层拖网作业过程中状态的变化趋势。结果表明:(1)上纲与第3~4节网身连接处深度差范围为-0.20~8.02 m,上纲与网囊口上部中点深度差范围为6.49~30.16 m;(2)曳纲长度、拖速、风速、150 m水层流速对磷虾拖网上纲深度影响显著(P< 0.05);上纲深度与曳纲长度和150 m水层流速呈正相关关系,与拖速呈负相关关系,随风速增加,上纲深度先减小后增大;(3)拖速、200 m水层流速和浪高对上纲与第3~4节网身连接处深度差影响极显著(P< 0.05);上纲与第3~4节网身连接处深度差具有随拖速和200 m水层流速的增加,先增大后减小的趋势;其中拖速2.6 kn和200 m水层流速0.3 kn时,上纲与网囊口上部中点深度差最大,2 m浪高时,深度差最小;(4)渔获量与上纲和网囊口上部中点深度差呈正相关关系;(5)曳纲长度是影响拖网作业状态的最重要因素,其次是拖网速度、风速、浪高和水流速度。  相似文献   
54.
Increasing pressures from agriculture and urbanization have resulted in drainage of many floodplains along the eastern Australian coastline, which are underlain by sulphidic sediments, to lower water tables and reduce soil salinity. This leads to oxidation of the sediments with a rapid decline in pH and an increase in salinity. Accurately mapping soil salinity and pH in coastal acid sulphate soil (CASS) landscapes is therefore important. One required map is the extent of highly acidic (i.e. pH < 4.5) areas, so that the application of alkaline amendments (e.g. lime) to neutralize the acid produced can be specifically targeted to the variation in pH. One approach is to use digital soil mapping (DSM) using ancillary information, such as an EM38, digital elevation models (DEM – elevation) and trend surface parameters (east and north). We used an EM38 in the horizontal (EM38h) and vertical (EM38v) modes together with elevation data to develop multiple linear regressions (MLR) for predicting EC1:5 and pH. For pH, best results were achieved when the EM38 ECa data were log‐transformed. By comparing MLR models using REML analysis, we found that using all ancillary data was optimal for mapping EC1:5, whereas the best predictors for pH were north, log‐EM38v and elevation. Using residual maximum likelihood (REML), the final EC1:5 and pH maps produced were consistent with previously defined soil landscape units, particularly CASS. The DSM approach used is amenable for mapping saline soils and identifying areas requiring the application of lime to manage acidic soil conditions in CASS landscape.  相似文献   
55.
在拖网渔船的设计中,需要重点考虑螺旋桨与船-机的匹配、渔具与船-机-桨的匹配,实现推进系统的高效能发挥。本文引入时间概率的最佳螺旋桨参数优化确定方法,考虑拖网渔船设计的限制条件,通过优化分析,达到运营工况综合效能最佳,实现螺旋桨与船-机的合理匹配。从拖网渔船数据库中选取30艘运营状况优良的渔船进行有效拖力计算,建立拖网渔船有效拖力与主机功率和拖速的多元非线性回归方程,依据此方程得出的有效拖力结果选择网具和网板,实现有效拖力与渔具的合理匹配,最终实现渔具与船-机-桨的合理匹配。通过实船计算对比,验证了回归的有效拖力估算公式误差范围和适用性。研究表明:在拖网渔船设计初期,可以利用该公式估算有效拖力进行网具和网板的匹配,实现技术经济优化论证,最终实现船-机-桨-网的优化匹配。  相似文献   
56.
乳山近海渔业资源种类组成及变化   总被引:1,自引:0,他引:1  
根据2013—2015年乳山近海拖网渔船的渔捞日志,分析了乳山近海的单位捕捞努力量渔获量、渔获种类组成及生物多样性等特征。结果表明:(1)乳山近海渔获物共有36种,隶属于19目28科33属。其中鱼类有26种,虾蟹类4种,头足类4种,水母类1种,贝类1种。(2)2013—2015年全年优势种差异明显。其中,蓝点马鲛3年均为优势种,鳀鱼是2014年和2015年优势种,网纹狮子鱼为2013年和2015年的优势种。(3)乳山近海渔获物主要集中在休渔期前后的4—5月、9—11月,渔业生产存在明显的春汛和秋汛。2013—2015年乳山近海单位捕捞努力量渔获量逐年增加,但与历史单位捕捞努力量渔获量相比还是存在明显下降;多样性指数和均匀度指数变化趋势一致,多样性指数和丰富度指数较高值出现在秋季;春汛和秋汛期间,渔业资源种属组成及群落结构相似性较高。  相似文献   
57.
  1. Dried gill plates from manta and devil rays, some of the world's most biologically vulnerable fishes, have become a valued commodity in Asian dried‐seafood and traditional Chinese medicine markets. This trade is a primary driver of fisheries, which have led to declines in many mobulid populations.
  2. With no reliable trade statistics and scarce data on mobulid fisheries, this study estimates the number and species of mobulids required to supply this trade, and investigates the consumers and suppliers involved and drivers of demand. Following preliminary market research, 525 trader surveys were conducted in Hong Kong, Singapore, Macau, Taiwan, and southern China.
  3. Guangzhou, China was identified as the centre of the trade accounting for 99% of total estimated market volume of 60.5 tons of dried gill plates in 2011, increasing to 120.5 tons by 2013. The estimated number of mobulids converted from tons of gill plates more than doubled over the period to 130 000, comprising 96% devil rays, Mobula japanica, Mobula thurstoni, and Mobula tarapacana, and 4% Manta spp. By 2015 the Guangzhou market had declined sharply, reportedly due to conservation campaigns and government policies. However Hong Kong's gill plate sales increased dramatically between 2011 and 2015.
  4. China, Indonesia, Vietnam, Sri Lanka, and India were reported most frequently as gill plate sources.
  5. Vendors recommend gill plates (trade name pengyusai) for ailments ranging from acne to cancer and as a general health tonic. While pengyusai is a new addition to traditional Chinese medicine literature and is rarely prescribed by traditional medicine practitioners, it is readily available over the counter and aggressively marketed by vendors.
  6. Working in concert with consumer demand reduction efforts, increased measures to restrict mobulid fisheries and trade are recommended to prevent further population declines of these highly vulnerable species.
Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   
58.
Vegetation indices are widely used as model inputs and for non‐destructive estimation of biomass and photosynthesis, but there have been few validation studies of the underlying relationships. To test their applicability on temperate fens and the impact of management intensity, we investigated the relationships between normalized difference vegetation index (NDVI), leaf area index (LAI), brown and green above‐ground biomass and photosynthesis potential (PP). Only the linear relationship between NDVI and PP was management independent (R2 = 0·53). LAI to PP was described by a site‐specific and negative logarithmic function (R2 = 0·07–0·68). The hyperbolic relationship of LAI versus NDVI showed a high residual standard error (s.e.) of 1·71–1·84 and differed between extensive and intensive meadows. Biomass and LAI correlated poorly (R2 = 0·30), with high species‐specific variability. Intensive meadows had a higher ratio of LAI to biomass than extensive grasslands. The fraction of green to total biomass versus NDVI showed considerable noise (s.e. = 0·13). These relationships were relatively weak compared with results from other ecosystems. A likely explanation could be the high amount of standing litter, which was unevenly distributed within the vegetation canopy depending on the season and on the timing of cutting events. Our results show there is high uncertainty in the application of the relationships on temperate fen meadows. For reliable estimations, management intensity needs to be taken into account and several direct measurements throughout the year are required for site‐specific correction of the relationships, especially under extensive management. Using NDVI instead of LAI could reduce uncertainty in photosynthesis models.  相似文献   
59.
Relative abundance of many shark species in the Atlantic is assessed by compiling data from several independently conducted, but somewhat spatially limited surveys. Although these localized surveys annually sample the same populations, resulting trends in yearly indices often conflict with one another, thereby hindering interpretation of abundance patterns at broad spatial scales. We used delta‐lognormal generalized linear models (GLMs) to generate indices of abundance for seven Atlantic coastal shark species from six fishery‐independent surveys along the US east coast and Gulf of Mexico from 1975 to 2014. These indices were further analysed using dynamic factor analysis (DFA) to produce simplified, broad‐scale common trends in relative abundance over the entire sampled distribution. Effects of drivers including the North Atlantic Oscillation index, the Atlantic Multidecadal Oscillation index, annually averaged sea surface temperature and species landings were evaluated within the DFA model. The two decadal oscillations and species landings were shown to affect shark distribution along south‐east US coast. Estimated common trends of relative abundance for all large coastal shark species showed similar decreasing patterns into the early 1990s, periods of sustained low index values thereafter and recent indications of recovery. Small coastal shark species exhibited more regional variability in their estimated common trends, such that two common trends were required to adequately describe patterns in relative abundance throughout the Gulf of Mexico and Atlantic. Overall, all species’ (except the Gulf of Mexico blacknose shark) time series concluded with an increasing trend, suggestive of initial recovery from past exploitation.  相似文献   
60.
Peatlands are highly valued for their range of ecosystem services, including distinctive biodiversity, agricultural uses, recreational amenities, water provision, river flow regulation and their capacity to store carbon. There have been a range of estimates of carbon stored in peatlands in the United Kingdom, but uncertainties remain, in particular with regard to depth and bulk density of peat. In addition, very few studies consider the full profile with depth in carbon auditing. The importance of sub‐peat soils within peatland carbon stores has been recognized, but remains poorly understood and is included rarely within peatland carbon audits. This study examines the importance of the carbon store based on a study of blanket peat on Dartmoor, UK, by estimating peat depths in a 4 × 1 km survey area using ground penetrating radar (GPR), extraction of 43 cores across a range of peat depth, and estimation of carbon densities based on measures of loss‐on‐ignition and bulk density. Comparison of GPR estimates of peat depth with core depths shows excellent agreement, to provide the basis for a detailed understanding of the distribution of peat depths within the survey area. Carbon densities of the sub‐peat soils are on average 78 and 53 kg C/m3 for the overlying blanket peat. There is considerable spatial variability in the estimates of total carbon from each core across the survey area, with values ranging between 56.5 kg C/m2 (1.01 m total depth of peat and soil) and 524 kg C/m2 (6.63 m total depth). Sub‐peat soil carbon represents between 4 and 28 per cent (mean 13.5) of the total carbon stored, with greater values for shallower peat. The results indicate a significant and previously unaccounted store of carbon within blanket peat regions which should be included in future calculations of overall carbon storage. It is argued that this store needs to be considered in carbon audits.  相似文献   
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