6月1日起沿海海域全部休渔

根据农业部伏季休渔制度调整方案,从6月1日12时起,我国北纬26度30分以北的黄渤海和东海海域休渔正式开始。其中,北纬35度至26度30分的黄海和东海海域的休渔时间截止到9月16日12时,北纬35度以北的黄渤海海域的休渔时间截止至9月1日12时。连同5月16日12时起开始实施的北纬26度30分以南海域伏季休渔,至此,我国2009年海洋伏季休渔全面实施。     

基于渔获物统计的中国近海鱼类营养级结构变换及其与捕捞作业的关系

为了解我国东部海域(渤海、黄海和东海)和南海的鱼类生态结构和渔业资源变化特征,本研究在1983—2013年中国海洋渔船渔获统计数据的基础上,首先将渔获物中的鱼类按照营养级归类,然后计算其平均营养级(TL)和Fi B指数,并结合海洋捕捞作业方式,对鱼类的营养级结构长期变化进行分析。结果表明,在东部海域捕捞的25种主要鱼类渔获中,31年间TL呈现下降趋势,低营养层级鱼类比例增长了60%,中营养层级鱼类比例增长了129%,高营养级鱼类则下降了近51%;而在南海,31年间TL变化不明显,低营养级鱼类比例下降了6%,中营养级鱼类下降了43%,高营养级鱼类增长198%。东部海域和南海的渔获物鱼类生态结构变化说明,就营养级水平而言,东部海域近海渔业资源呈现明显的衰退现象,而南海则还未出现这种现象。     

浙江省海洋渔业的现状及其发展趋势

<正> 一、浙江海洋渔业在我国的地位我国海洋渔业是以近海为基础,主要渔场有渤海、黄海、东海和南海。海洋捕捞产量年产200多万吨左右。近几年来由于资源和捕捞技术的变化。东海渔场日益处于左右全国海洋渔业的地位。     

从休渔制度浅谈我国近海渔业的发展之路

正我国最早从1979年开始在浙江省先行实践休渔政策,几经发展到1999年休渔范围覆盖到渤黄海、东海、南海等所有中国的近海海域。之后在2000、2003、2007、2009等年份几经调整,现今休渔范围规定更详细,各种作业允禁更明确,整体休渔时间延长。时至今日我国休渔政策将近海分为北纬35度以北的渤海和黄海海域、北纬35度至26度30分的黄海和东海海域、北     

农业部重新调整海洋伏季休渔制度

正本刊讯为进一步贯彻落实《渔业法》《中国水生生物资源养护行动纲要》以及生态文明建设要求,更好地保护海洋渔业资源,农业部本着总体稳定、局部优化、减少例外、利于监管的原则,决定对海洋伏季休渔制度进行调整完善。2月8日,农业部就调整后的海洋伏季休渔制度发布通告。休渔海域:渤海、黄海、东海及北纬12度以北的南海(含北部湾)海域。休渔作业类型:除钓具外的所有作业类型,以及为捕捞渔船配套服务     

农业部调整黄渤海区刺网休渔时间

<正>近日,农业部发布通告,决定将黄渤海区刺网休渔时间调整为6月1日12时至9月1日12时,东海区、南海区刺网休渔政策暂不变更。调整后的伏季休渔规定,自2014年1月1日起施行。休渔海域渤海、黄海、东海及北纬12度以北的南海(含北部湾)海域。休渔作业类型(一)"闽粤海域交界线"以北的渤海、黄海、东海海域:除钓具外的所有作业类型。(二)北纬12度至"闽粤海域交界线"的南海海域(含北部湾):除单层刺网和钓具外的所有作业类型。     

每月要闻

6月1日，我国北纬26度30分以北的黄渤海和东海海域正式开始伏季休渔，连同5月16日开始实施的北纬26度30分以南的南海海域伏季休渔，至此，我国2009年海洋伏季休渔全面实施。     

远洋渔业相关管理规定

<正>远洋渔业,是指中华人民共和国公民、法人和其他组织到公海和他国管辖海域从事海洋捕捞以及与之配套的加工、补给和产品运输等渔业活动,但不包括到黄海、东海和南海从事的渔业活动。农业部对远洋渔业实行项目审批管理和企业资格认定制度,并依法对远洋渔业船舶和船员进行监督管理。远洋渔业项目申请和审批     

捕捞压力和气候变化对东海马面纯渔获量的影响

为了研究捕捞压力和气候变化对东海马面纯（Navodon spp．）渔获量的影响,对1976年～2006年的东海马面纯渔获量进行了分析。东海马面纯渔获量可划分成因捕捞效应所产生的趋势变化和因气候变动所导致的渔获量变动,前者可用Fox模型来拟合。Fox模型拟合结果显示,东海马面纯渔获量与捕捞努力量显著相关（P〈0．01）。移除捕捞压力增长引起的变化趋势后,其渔获量变动与热带气旋影响指数、东海海表温度、东海冬季季风和黄海夏季季风呈显著正偏相关（P〈0．03）,与热带气旋影响指数、黄海冬季季风及长江流域和东海沿岸降雨呈显著负偏相关（P〈0．03）。根据捕捞努力量和气候变量对东海马面纯渔获量进行拟合,结果显示,拟合的渔获量与实际渔获量显著相关（R=0．91,P〈0．01）,说明捕捞压力和气候变化显著影响东海马面纯渔获量的变动。此外,由于未来气候的变化,东海马面鲍渔获量可能出现更大波动。     

中国近海沉积物中重金属的变化特征和生态风险评估

通过对2008—2012年中国近海(南海、东海、黄海、渤海)采集的沉积物样品中重金属含量的测定,结合风险评价的手段,研究了各海域沉积物中重金属含量的空间变化特征、影响因素和潜在生态风险。结果表明,东海沉积物的重金属含量最高,黄海次之,渤海和南海相对较低。沉积物中重金属含量与粒径在不同海域呈现出不同相关性:在南海呈现显著负相关,说明其含量与物源相关,人为影响相对较少;在东海的相关性相对较弱,说明其含量除受物源影响外,很大程度受到外界输入人为影响;在黄海和渤海基本无相关性,说明其含量主要受人为输入影响。重金属污染程度(C_d)和潜在生态危害指数法(E_(RI))均呈现出相似的结果:东海南海黄海、渤海,说明东海是潜在生态风险最高的海域。且C_d和E_(RI)均呈现由近岸向外海降低的趋势,说明近岸潜在生态风险较外海高。     

RESOURCE ALLOCATION EFFICIENCY OF THE PRAWN-CARP FARMERS OF BANGLADESH

This paper evaluates resource allocation efficiency of prawn-carp polyculture systems by making use of the data of 105 farmers of Bangladesh. Data Envelopment Analysis (DEA) was employed to estimate the efficiency. Mean technical efficiency (TE), allocative efficiency (AE) and cost efficiency (CE) were 85%, 58%, and 49%, respectively. Fifty percent of prawn-carp farmers displayed full TE whereas only 9% were cost efficient. Actual input application largely deviated from the technical and cost-efficient levels. TEs and AEs showed a positive and negative correlation with pond size, respectively. Labor, fingerlings and feed were overused while organic and inorganic fertilizers were underused in general. Adjustments in actual input allocations were necessary to make use consistent with TE and CE levels. The study concludes that mere achievement of technical efficiency in prawn-carp production may be a short-run concern; the farmers have to be economically efficient in the long-run.     

中国对虾同化率和转换效率的初步研究

我国广泛开展对虾养殖已有近二十年的历史,由于发展和管理不当,产生了严重的环境污染和病害问题,使养虾产量大幅度下降［王清印１９９４］。虽然虾病的暴发性流行是对虾减产的直接原因,但环境条件的恶化也是一个主要因素。在中国对虾的池塘养殖中,其生长和代谢的能量...     

关于陕西省农业生产技术效率的实证分析

文章采用DEA（数据包络）分析方法,从纵横两个方向对陕西省农业生产综合技术效率、纯技术效率和规模效率进行分析,对非DEA有效的地区进行松弛量分析和射影调整,指出其非有效的原因及程度,并给出其应调整规模的正确方向和大小。     

Economic efficiency of small-scale tilapia farms in Guangxi,China

ABSTRACT

The economic efficiency of small-scale tilapia farms in Guangxi, China were analyzed by using Data Envelopment Analysis (DEA). The mean technical (under CRS and VRS), allocative, and economic efficiencies of small-scale tilapia farms were 0.89, 0.97, 0.71 and 0.68, respectively. Efficiency analysis revealed that inefficient farms would have needed to increase production output levels by 32% to perform as well as the best practice farms. The decomposition of the economic efficiency showed that allocative inefficiency was the primary cause of economic inefficiency. There were positive relationships between economic efficiency and age, culture mode and period through Tobit regression, while experience, family members, and technology support had negative effects on economic efficiency. Lower input levels of feed quantity may help to increase the tilapia farming economic efficiency.     

潜流湿地技术在高密度养殖尾水处理中的应用

构建"潜流湿地+生物净化"的湿地生态系统,并以纯生物净化系统作为对照区,研究其对池塘高密度养殖尾水中总氮(TN)、总磷(TP)、高锰酸盐指数(CODMn)、悬浮物总颗粒(SS)指标的去除效果,并对试验区与对照区内的产量与效益进行分析。结果表明:构建湿地生态系统后,区域内养殖面积有所减少,但产量与效益却有所提高。试验区的净化面积占整个养殖系统的7.9%,远远小于对照区的净化面积占比18.8%。对TN、TP、CODMn的去除率分别为80.8%～90.9%、78.95%～88.18%和23.20%～27.24%,对照区对相应指标的去除率分别为70.8%～88.7%、76.09%～87.14%和15.38%～25.08%,试验区的去除效率略高于对照区。至2011年,试验区与对照区的池塘生产各类水产品产量分别比2009年增长24.8%与19.2%、销售收入分别增长了26.4%与14.8%、利润分别增加了35.2%与18.64%。试验区产量与效益明显好于对照区。因此,潜流湿地方式净化水质节省了土地资源,提高了鱼池利用率及养殖效益,与纯生物净化相比具有明显的优越性。     

A comment on transfer efficiencies

This paper discusses the validity of several assumptions in a recent publication on the primary production required to sustain the annual world fish catch of £120 million t. A transfer efficiency between trophic levels in aquatic ecosymms of 15% results in the primary production requirement of 2.6% of the total primary production to sustain the world fish catch, not 8% as reported from calculations with a transfer efficiency of 10%. The importance of accurate estimates of predation efficiency and trophic level is shown.     

Effect of various sources of dietary additive on growth,body composition and serum chemistry of juvenile olive flounder (Paralichthys olivaceus)

Asia traditional herbal feed additives have often been shown to have beneficial effects on disease resistance, growth, feed conversion and protein conversion. There have been few studies on the use of these feed additives in olive flounder diets. The present study was designed to determine if there are benefits associated with the inclusion of any of these traditional herbal feed additives in olive flounder diets. One thousand two hundred sixty juvenile fish averaging 6.5 g were randomly distributed into 36, 180‐L flow‐through tanks. No additive was included into the control (Con) diet. The aqueous type of additives: 2.5% bamboo (BB), 0.25% Prunus mume (PM), 2.5% Artemisia capillaris (AC), 2.5% cinnamon (CC), 2.5% Cirtus junos (CJ), 0.25% Cudrania tricuspidata (CT) and 2.5% Ficus carica (FC), and the powder type of additives: 1% Houttuynia cordata (HC), 1% safflower (SF) and 1% sea tangle (ST) were included into the experimental diets. Finally, 0.1% emulsifying oil (EO) was included into the experimental diet. Feed efficiency ratio (FER) of fish fed the BB, CT and SF diets was higher than that of fish fed the FC and HC diets. Protein efficiency ratio (PER) of fish fed the BB and SF diets was higher than that of fish fed the AC, FC and HC diets. None of serum criteria of fish was affected by any of dietary additives. Dietary additives did not affect weight gain and serum chemistry of olive flounder, but 2.5% bamboo extract and 1% safflower powder was effective to improve FER and PER.     

Efficiency of fisheries is increasing at the ecosystem level

Managing fisheries presents trade‐offs between objectives, for example yields, profits, minimizing ecosystem impact, that have to be weighed against one another. These trade‐offs are compounded by interacting species and fisheries at the ecosystem level. Weighing objectives becomes increasingly challenging when managers have to consider opposing objectives from different stakeholders. An alternative to weighing incomparable and conflicting objectives is to focus on win–wins until Pareto efficiency is achieved: a state from which it is impossible to improve with respect to any objective without regressing at least one other. We investigate the ecosystem‐level efficiency of fisheries in five large marine ecosystems (LMEs) with respect to yield and an aggregate measure of ecosystem impact using a novel calibration of size‐based ecosystem models. We estimate that fishing patterns in three LMEs (North Sea, Barents Sea and Benguela Current) are nearly efficient with respect to long‐term yield and ecosystem impact and that efficiency has improved over the last 30 years. In two LMEs (Baltic Sea and North East US Continental Shelf), fishing is inefficient and win–wins remain available. We additionally examine the efficiency of North Sea and Baltic Sea fisheries with respect to economic rent and ecosystem impact, finding both to be inefficient but steadily improving. Our results suggest the following: (i) a broad and encouraging trend towards ecosystem‐level efficiency of fisheries; (ii) that ecosystem‐scale win–wins, especially with respect to conservation and profits, may still be common; and (iii) single‐species assessment approaches may overestimate the availability of win–wins by failing to account for trade‐offs across interacting species.     

盐碱地池塘不同养殖模式的能量利用比较

于1998年4—9月采用围隔实验生态学方法,为鲤、草鱼、罗非鱼、淡水白鲳及鲢、鳙设计了4种混养模式。经测定,淡水白鲳模式(FP)、草鱼模式(GC)和罗非鱼模式(TH)模式的光能利用率都随吃食性鱼类放养密度的增大而升高,GC和TH的光能利用率相对较高;总能量转化率以鲤模式(CC)和FP较高,TH最低;饲料能转化效率在FP最高,TH最低,而且各放养模式都随吃食性鱼类放养密度的增大而下降;FP的N利用率很高,TH最低,N和P利用率在4种模式都随吃食性鱼类放养密度的增大而减小;各模式的产投比都随吃食性鱼类放养密度的增大而增大,CC、TH的产投比在吃食性鱼类放养密度最大时有所下降。     

中国农业用水效率区域差异与空间交互机理研究

基于2005-2019年中国31省份面板数据，采用超效率SBM模型和全要素用水效率指标，测度中国农业用水效率。并利用向量自回归模型（VAR），探究中国省域间农业用水效率的交互作用和溢出效应。结果表明：中国农业用水效率总体偏低， 2019年为0.690，存在31%的提升空间。农业用水综合效率与纯技术效率、规模效率呈正相关，但省份之间相关程度存在差异。西藏自治区纯技术效率最高，为1.022，山西省规模效率最高，为0.995。研究期内，中国农业用水效率均值集聚特征不显著，浙江、西藏和海南等三省（区）处于孤岛状态。中国农业用水效率呈西高东低，北高南低总体分布态势。VAR脉冲分析显示中国农业用水效率存在正向空间交互作用，其中以东部地区对中西部影响最为显著。要提高中国农业用水效率，一方面要重视农业科技创新，提高农业用水纯技术效率；另一方面要加强区域协作，充分发挥高效率用水区域的溢出效应