中国农户精养淡水鱼技术效率分析

本文从技术效率分析和前沿生产函数原理出发，以2002和2003年我国农户精养淡水鱼成本收益统计资料为样本，利用SPSS统计分析软件构建我国农户精养淡水鱼的柯布一道格拉斯生产函数的确定型统计前沿模型，并测定我国主要省市农户精养淡水鱼的技术效率值，得出结论为我国农户精养淡水鱼生产存在着技术效率不高、波动幅度较大、地区差异较大的现状。     

确定性前沿模型及其在测定我国农户精养淡水鱼技术效率中的应用

研究概述了确定性前沿模型的产生、分类、特点、参数求解方法及其在我国的应用现状。在此基础上,以2002年和2003年我国农户精养淡水鱼成本收益资料为样本,应用前沿模型理论建立了我国农户精养淡水鱼的确定性统计前沿模型并测定了这两年中我国主要淡水鱼养殖省市的农户精养淡水鱼技术效率,得出结论为:物质资本投入对我国农户精养淡水鱼产出的影响远大于劳动力投入;我国农户精养淡水鱼生产处于规模报酬不变阶段;我国农户精养淡水鱼生产存在着较大的技术无效性和管理缺失现状,这一现状存在着明显的地区差异和时间差异。     

池塘养殖商品鲤高产技术的研究

近年来,池塘养鲤在北方各省市迅速发展,并已形成一定生产规模,对提高各省市的淡水鱼产量和加速淡水养鱼生产发展起到了重要作用。为了探索静水池塘养殖商品鲤的高产技术及其增产潜力,我们从1988年起利用本场     

我国渔业发展科技功不可没

据专家测算，目前我国渔业的技术进步贡献率已达48％，比我国农业平均科技进步贡献率高6％。在我国渔业的发展进程中科技发挥了巨大的作用。我国已有o000多项渔业科技成果获省部级以上奖励，4．3万多科技人员活跃在渔业科技推广一线。在海水养殖方面，中国对虾、扇贝的入工育苗和养殖技术的突破与推广，使我国海水养殖品种的构成和质量发生了根本性变化。过去，我国水产养殖的大宗品种主要是传统的四大家鱼和贝类、藻类为主的少数品种，现在则有鱼、虾。蟹、贝类为主的几十个品种，名特优产品比重较大。淡水池塘精养高产技术推广以后，我国…     

沈阳地区鱼类养殖的病害及其防治对策

沈阳市是全国重点淡水鱼生产基地之一,其养殖区域主要分布有:辽中、新民、康平、法库、苏家屯区、于洪区、新城子区等地。全市精养面积共20余万亩,淡水鱼产量达10余万吨,产值达8亿元。市政府在“十五”规划期间,计划淡水鱼产量达到14万吨,产值达到11亿元,年增长速度分别为27.2％和 37.5％。淡水鱼主要品种有鲤、鲫、草、团头鲂、河蟹等,目前正引进的新品种有鲶鱼、白鲳、     

唐山市淡水鱼产业发展现状及今后发展方向

正唐山市淡水鱼产业在河北省渔业产业中占据重要地位,养殖面积和养殖产量居省内首位,养殖品种主要包括鲤鱼、草鱼、鲫鱼等大宗淡水鱼以及其它名特优养殖种类,是水产业的一大经济增长点。1唐山市淡水鱼产业发展现状1.1养殖区域分布2014年,全市淡水养殖面积1.97万hm2,其中池塘养殖面积1.67万hm2,大部分是池塘精养模式。主要分布县区为:曹妃甸区6 867hm2、丰     

乌鳢精养高产技术推广试验报告

2002—2003年，我们实施了乌鳢精养高产技术推广项目，取得了显著的经济社会效益。现将本项目技术总结如下：     

关于加速发展淡水创汇渔业的探讨

一、发展创汇渔业的重要意义 党的十一届三中全会以来，我省淡水渔业出现了前所未有的大好形势，产量大幅度提高。1986年全省淡水鱼总产量达19．11万吨，取得了连续第八个丰收年，年增长幅度为20％。近几年我省在狠抓小水面精养高产稳产的同时，     

南美白对虾淡化养殖技术试验

南美白对虾1987年从美洲引入我国大陆，1987～1994年．我国取得了南美白对虾的全人工育苗养成试验成功．为进一步大规模育苗及养成生产奠定了理论和使用基础。1995-1998年，我国少数地区开展了南美白对虾的试养．养殖技术日趋成熟。近3年南方三省区(广东、广西、福建)，每667m^2取得了单茬精养产量500kg，精养1t，工厂化养殖3t的产量。     

南美白对虾工厂化集约养殖技术探讨

舟山市水产养殖部门为探索海岛地区多种模式发展南美白对虾养殖,于2002年有选择性地扶持养殖大户开展南美白对虾高密度精养,帮助构建工厂化标准虾池并全过程指导养殖生产。现将其中主要示范点定海区旭旺养殖场3年(2003～2005年)南美白对虾工厂化集约养殖的有关生产工艺与技术特点予以推介及研讨。     

团头鲂全产业链健康养殖技术研究进展及展望

团头鲂是我国主要的淡水养殖鱼类之一，其具有食性广、养殖成本低、生长快、成活率高、易捕捞、易繁殖等特点，且具有味美、头小、含肉率高、体形好、规格适中等优点，深受消费者欢迎，在增加优质水产动物蛋白供应、提高全民营养健康水平、保障我国食物安全等方面做出了重要贡献。本文综述了团头鲂全产业链技术研究进展，包括新品种培育及育种技术、饲料营养需求调控及投喂技术、养殖应激与病害的生态防控技术、新型养殖模式、营养品质及加工技术等，提出了具有生产性能优、抗病抗逆性强和适于加工的团头鲂种质资源的挖掘，集约化健康养殖模式建立及精准营养供给、生态防控和高品质加工调理技术的研发等产业发展需求和研究方向，以期为团头鲂全产业链的绿色高质量可持续发展提供参考。     

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。     

Induced ovulation using LHRHa in anadromous obscure puffer Takifugu obscurus cultured entirely in freshwater

Puffer fishes of the order Tetradontidae exist in both anadromous and non-anadromous seawater resident forms. The obscure puffer akifugu obscurus is an anadromous species whose intensive culture in freshwater has developed rapidly in China. To mass produce larvae for intensive culture, induction of ovulation of 3-year-old obscure puffer cultured entirely in freshwater was attempted by giving the fish multiple injections of LHRHa. Twenty 3-yearold cultured obscure puffers were treated with multiple injections of LHRHa at a constant dosage of 30 g of LHRHa kg-1 of body weight with 36 h interval between injections. Beginning two days after hormonal treatment, abdominal palpation was performed every day to check expansion and hardening of the abdomen of the fish due to hydration of oocytes that indicates the completion of final oocyte maturation. The first four fish ovulated after the second LHRHa injection on day 3, but most females ovulated after the fourth hormone injection. A total of 18 fish (90%) ovulated over a period of 7 days, while no fish ovulated in the control group. The mean fertilization rate and the mean hatch rate was 67.1% and 87.6%, respectively. The viability of newly hatched larvae was very good, with a high survival rate of 98.6% 24 h post-hatch. These results indicate that cultured obscure puffer, which are not allowed to undergo diadromous migration and are entirely cultured in freshwater, could be induced to complete maturation and ovulate by simple multiple injections of LHRHa and that the eggs could be successfully hatched into viable larvae.     

Reduced total hardness of fresh water enhances the efficacy of bathing as a treatment for amoebic gill disease in Atlantic salmon, Salmo salar L

The current treatment for amoebic gill disease (AGD)-affected Atlantic salmon involves bathing sea-caged fish in fresh water, often sourced from local dams, for 3-4 h. In both a small-scale laboratory and an on-farm field experiment, the effects of water hardness on the efficacy of freshwater bathing were assessed. Results showed that soft fresh water (19.3-37.4 mg L(-1) CaCO3), whether it be naturally soft city mains water or artificially softened dam water, was more efficacious at alleviating AGD in affected fish than hard fresh water (173-236.3 mg L(-1) CaCO3). Soft freshwater bathing significantly reduced viable gill amoebae numbers (from 73.9 to 40.9% of total count) and significantly alleviated gill pathology, both gross and histological. Following bathing, gross gill pathological scores of soft freshwater bathed fish lagged 2 weeks behind hard freshwater bathed fish. Significant gill lesion fragmentation, and shedding of lesion-associated hyperplastic tissue, was accompanied by a significant reduction in AGD-affected gill filaments in soft freshwater bathed fish. Furthermore, soft freshwater bathing alleviated the blood plasma electrolyte imbalance seen in control (sea water) and hard freshwater bathed fish. This study showed that the use of soft fresh water for bathing AGD-affected Atlantic salmon could be an improvement to the current method of treatment. Not only does it reduce gill amoeba numbers, but also, it is of a therapeutic advantage with the potential to reduce bathing frequency.     

大水面鳜增殖放流技术及效果评估研究进展

鳜(Siniperca chuatsi Basilewsky)是淡水生态系统中的顶级捕食者,也是我国传统的渔业对象.多年来由于人类活动的过度干扰导致现阶段湖泊、水库等大水面鳜自然资源衰退严重.增殖放流作为水生生物资源养护和恢复的重要措施在世界各国大量开展.近年来针对鳜增殖放流开展了一系列基础性研究工作,切实提高了鳜增殖...     

Water quality and freshwater fish culture intensification: the Israeli example

Abstract. During the development of freshwater fish culture in Israel there has been a trend toward intensification, which has been accelerated in the last years with the introduction of new culture systems: deep reservoirs, fish cages and mechanically stirred ponds. In the present paper, the main processes affecting water quality variability in outdoor systems with increasing fish culture intensification levels are presented. The analysed systems are semi-intensive shallow ponds with different organic loading, semi-intensive shallow ponds with different fish species combinations, semi-intensive deep reservoirs, and intensive mechanically stirred ponds. The examples are from experiments conducted at the Fish and Aquaculture Research Station Dor and from follow-ups at fish farms.     

鄱阳湖物理生境特征及其对鱼类群落结构的影响

湖泊鱼类群落结构与物理生境特征密切相关。为了探究鱼类群落结构与物理生境特征之间的关系,在鄱阳湖设立17个采样点,通过采集鱼类样本研究其群落结构,并利用遥感技术分析样点物理生境特征（包括岸线分形维数、距离指数和高程值）及其空间区域差异。结果表明,依据17个采样位点的物理生境特征,鄱阳湖丰水期物理生境空间上可以划分为3个区域,分别为北方区、南方区和主湖区,但枯水期鄱阳湖生境没有显著的区域划分规律。丰水期鄱阳湖鱼类可以分为北方群、南方群和主湖区群3个类群,而枯水期鱼类组成没有明显规律。从功能类群上看,鄱阳湖鱼类以杂食性、湖泊定居性和偏好于底层以及中下层栖息的中小型鱼类为主。不同区域的鱼类功能群之间存在时间和空间上的变化,北方区和南方区鱼类功能群组成相似,主湖区与北方区和南方区存在差异。总体上,鱼类群落结构的时空变化和差异与物理生境特征具有良好的一致性;未来鄱阳湖鱼类的保护工作需要关注湖泊物理生境特征,不同区域应制定不同的保护措施。     

Technical efficiency of carp production in Pakistan

Abstract

The main objective of this study is to examine technical efficiency and its determinants in carp pond culture in Pakistan. A stochastic production frontier involving the model for technical inefficiency effects is applied separately to the samples of semi‐intensive/intensive and extensive carp producers. The mean technical efficiencies for semi‐intensive/intensive and extensive farms were 0.673 and 0.561, respectively. By operating at full technical efficiency the semi‐intensive/intensive farms could, on average, increase their production from 3.0 to 4.5 Mt/ha and the extensive farms from 2.6 to 4.6 Mt/ha. Much of these efficiency gains would come from the improvement in fish, water and feed monitoring and management. Besides improving technical efficiency, potential also exists for raising carp productivity through increased intensification and technological progress. However, the realization of these potentials will depend on continuous government support for adequate provision of inputs, market and infrastructure, technology transfer and development and extension and credit services to carp farmers.