养殖长毛对虾虾体长体重关系式研究

长毛对虾(Penaeus Penicillatus Aicock)是福建省近海大型虾类优势种群,也是我国南方对虾养殖优良的种质资源之一。福建省于1979年开展生产性养殖试验获得成功,尔后逐步推广发展到目前20多万亩的养殖规模。虽然近几年开展多种虾和多季虾养殖,但是长毛对虾养殖面积仍占重要地位。     

广东省对虾康养殖与可持续发展的对策

虾病是对虾殖业的最大危害,每年因虾病全球对虾养殖的产量减少一半,损失几百亿元人民币。１９９３年,由于对虾病毒性疾病的暴发,我国对虾养殖业出现大幅度滑坡,使年产对虾２０多万吨、年创汇５亿美元,成为世界养虾大国的我国对虾产业走入低谷,随后,为了恢复和发展对虾养殖业,广大科技工作和虾农做了大量的科研攻关和细致的工作,付出了艰辛的劳动,取得了积极的成果,但在全国范围内,对虾养殖业仍没有恢复到虾病暴发流行前的水平,并存在一定的差距,虾病依然是对虾养殖业的瓶颈。本对广东省对虾养殖的现状和问题,提出对虾健康养殖与可持续发展的对策与措施。     

华南地区对虾养殖模式与清洁健康养殖关键技术(一)

我国是世界主要的养虾大国,自1997年我国进入对虾养殖恢复和快速发展时期,养殖产量已经跃居世界前列,成为世界第一养虾大国,2007年对虾养殖产量126万吨,占世界养殖对虾产量的40%。华南三省区对虾养殖产量显著提升,养殖对虾产量由1992年不足4万吨发展到2007年超过70万吨,占全国养殖对虾产量的55%以上。     

对虾养殖中水色和诱明度的意义和调节方法

养虾先养水是广大虾农和对虾养殖者的共识。而水色和透明度的好坏，是关系到对虾养殖的成败，但有些虾农，特别是初次养殖的虾农，对水色和透明度的重要性认识不足。例如有的虾农认为，养殖对虾透明度越大，底质就越干净，水质就越好；有的虾农缺乏调节水色和透明度的基本知识，花了很大本钱还是没有培养出良好水色和透明度。因为调节好水色和透明其中有许多学问。为此，我们特地谈谈水色和透明度在对虾养殖中的意义和调节方法，供参考。[第一段]     

2008-2010年渔业科技入户主导品种和主推技术（六）

对虾【品种来源】我国对虾养殖的品种有南美白对虾、中国对虾、斑节对虾和日本对虾等。1992年流行性虾病爆发前,以养殖中国对虾为主,目前以养殖南美白对虾为主。2006年,南美白对虾养殖产量占对虾养殖总产量的82%。1988年4月和1991年4月,     

93‘对虾暴发性流行病的病因和今后对策

９３’对虾暴发性流行病的病因和今后对策我国的对虾养殖业。从１９７８年全国海水养殖会议提出在沿海大面积推广人工养殖以来．１５年来发展突飞猛进、目前，从养虾整个生产和总体技术水平看；对虾养成（商品虾养殖）。人工育苗和亲虾越冬基本都是成功的。对虾病害尽管是...     

细角对虾的养殖技术及其与凡纳对虾的比较

对虾养殖业是我国海水养殖的支柱性产业，也是亚洲和美洲许多发展中国家的支柱性海洋产业。我国的对虾养殖产量和养殖规模曾在19881992年居于世界首位，年产量达20多万吨，年产值近百亿元，产生了显著的经济效益和社会效益．为我国沿海农村经济的发展做出了巨大贡献。但是，1993年养殖对虾病害的暴发性流行，导致了整个对虾养殖产业的严重滑坡，不仅对虾养殖业本身经济损失巨大，而且相关的对虾加工和出口等行业也受到严重影响，我国由对虾出口国变为进口国。近几年来，我国加强了对虾病害防治和养殖高新技术的研究与应用，同时也积极引进凡纳对虾(俗称南美白对虾)和细角对虾(俗称蓝对虾)等新的虾种进行养殖，特别是我国华南地区采用高位池和过滤海水防病养虾系统等高新技术进行凡纳对虾和斑节对虾养殖取得了显著的成功，促进了我国对虾养殖产量的迅速回升，对虾养殖业又开始出现增产增收的良好局面。2000年华南地区养殖对虾产量增长迅速，达到12万多吨，其中约5万吨是凡纳对虾；仅广东省就达到7．5万多吨．超过全国产量的1/3。采用新的集约化防病养殖技术，凡纳对虾单造产量普遍达到510吨，公顷，高的年产量已达到20吨，公顷，在江苏、山东等地进行小规模养殖也取得了成功，其养殖成功率和效益优于我国原有的斑节对虾和中国对虾，华南地区现已成为我国养殖对虾的主产区。2000年我国华南地区引进细角对虾进行试养取得成功，个别地区单造产量达到610吨，公顷，成为我国南方对虾养殖中又一个新的种类。但是，国内对于细角对虾的研究刚刚开始，缺乏专门介绍该虾的资料，广大虾农对此虾也了解不多。作者在此对细角对虾的养殖技术作一简单介绍，并与凡纳对虾等其他滨对虾属种类进行比较，提供给有关科研人员和养虾业者参考，希望对我国细角对虾养殖技术的发展有所帮助。     

华南地区对虾养殖的主要模式及特点

我国是世界主要的养虾大国,自1997年进入我国养殖对虾恢复和快速发展时期,养殖产量已经跃居世界前列,成为世界第一养虾大国。2006年养殖对虾产量107万吨,占世界养殖对虾产量40％。华南三省区对虾养殖产量显著提升,养殖对虾产量由1992年不足4万吨发展到2006年超过66万吨,占全国养殖对虾产量的57％。     

斑节对虾健康养殖技术的探讨

斑节对虾是合浦乃至广西对虾养殖的主要品种，１９８８年开始引进合浦养殖，１９９９年斑节对虾养殖面积达到３７３３公顷，发展迅猛。但随着养殖规模不断扩大，养殖病害不断发生，特别是１９９３年全国普遍出现暴发性虾病后，给对虾养殖业带来了沉重打击。广大科技工作者围绕着如何做好虾病的综合防治，实施对虾健康养殖进行不懈努力，虽然仍未能摆脱虾病的困扰，但是探索出许多养虾新技术、新方法，积累了丰富经验，有效地减少虾病发生。笔者阐述的斑节对虾健康养殖技术是我县１９９９年对如何进行低产虾塘技术改造，实施对虾健康养殖建立…     

渤海湾沿岸养殖对虾疾病流行情况及病因的初步分析

随着对虾养殖规模的不断扩大,对虾疾病也在各地流行起来,虾病已成为发展养虾生产的制约因素之一。据报道,虾病有七大类,约40种。1980年我国养殖对虾仅发现七种疾病,到1989年增加到30余种。河北省沧州地区对虾养殖生产从1983年开始起步,到1990年已形成较大规     

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.     

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.     

中国东海、黄海及南海捕捞能力的比较分析

以《中国渔业统计年鉴》中2009~2014年东海、黄海、南海的海洋捕捞渔船数、总功率、总吨位作为不变投入,专业劳动力作为可变投入,海洋捕捞产量为产出,使用数据包络分析法(data envelopment analysis,DEA)对捕捞能力利用度以及理想投入进行分析,总结2009~2014年各海域的规模效率和纯技术效率,计算无偏能力利用度,评价投入配置的合理性以及各生产投入因素对能力利用度的影响。结果表明:黄海海域捕捞纯技术效率较高,但能力利用度受资源衰退的影响明显,并有下降趋势,存在大比例的生产浪费,生产规模亟需优化;东海海域能力利用度和纯技术效率都呈稳定增长趋势,近年对生产投入的控制有一定成效,可变投入配置比例也较合理;南海海域能力利用度和技术效率趋势与东海海域相同,但减船转产实施的不明显,生产投入还有一定的缩减空间。     

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

测度农业水资源效率并对其空间交互机理进行深入解析,为提升农业用水效率提供参考。基于2005-2019年中国31省（市、区）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（市、区）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（市、区）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。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。