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我地区稻田养鱼有着悠久的历史.全州、兴安等地的“禾花鱼”全国闻名。1986年全地区稻田养鱼面积达36万亩,占稻田总面积的44.7%,产鱼2580吨,平均亩产7.15公斤,占渔业总产量的36.5%。鉴于我地区:稻田养鱼面积大,单位面积鱼产量低,所以提高稻田养鱼单产,是加快我地区渔业生产发展的一条捷径。为此, 相似文献
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1.依据稻鱼结合方式,可将稻田养鱼方法分为稻鱼并作型稻田养鱼、稻鱼轮作型稻田养鱼和稻鱼间作型稻田养鱼三种类型。(1)稻鱼并作型稻田养鱼。即种稻养鱼在同一田块同时进行。这是比较普遍的养殖方法。根据水稻栽收手段又可将这一方法划分为单季稻田养鱼和双季稻田养鱼。单季稻田养鱼还可根据水稻成熟季节划分为早稻田稻田养鱼、中稻田稻田养鱼和晚稻田稻田养鱼。双季稻田养鱼根据鱼类是否连养可划分为双车独立种养稻田养鱼(即随着稻谷的两次裁收,鱼类也相应两次放捕)和双车速养稻田养鱼。(2)稻鱼轮作型稻田养鱼。即稻田种稻时不养… 相似文献
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稻田养鱼既可改善稻田生态环境,充分利用稻田生物资源,发展淡水养鱼,又可以使粮食获得增产。目前我县稻田养鱼还是沿用传统的养殖方式,只是单养“禾花鲤刀一种,鱼产量低,一般亩产只有2.5~5公斤,同时在生产过程中稻鱼存在一些矛盾,诸如晒田、施肥、使用农药等等。 相似文献
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邵东县汪塘乡在今年中央一号文件精神指引下,把大力发展稻田养鱼作为调整农业内部结构的一项重要内容来抓,推动了全乡稻田养鱼的发展,八四年稻田养鱼470亩,今年发展到1240亩,比八四年增加1.63倍,并组织双龙、寨岭、小吾、莲塘等八个村,开展亩产“双纲粮百斤鱼”的稻田养鱼高产试验。成片稻田养鱼面积达514.5亩,占该乡稻田养鱼面积的41.6%。 相似文献
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随着稻田养鱼技术的不断改进和提高,稻田养鱼的鱼放养量不断增加。鱼病也随之发生,如何控制鱼病的发生和蔓延就成为稻田养鱼获得高产的关键。下面,笔者就几年来从事稻田养鱼的经验,介绍几种稻田养鱼防治鱼病的方法。一、对大田进行精心改造,认真清整,彻底消毒首先,在大田中开挖鱼沟鱼坑。鱼坑、鱼沟各占大田面积的40%左右,坑深1米以上,位于进水口;沟深0.5米以上,宽0.8米以上。坑沟相通,与大田用一02~0.3米高,0.15米宽的小田埂隔开,使沟坑可独立排灌,又可与大田串灌。其次,第一年挖好沟坑后,每年冬季应清整一次,挖去… 相似文献
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祁东县白地市镇乌山冲村,10个村民小组,245户,868人,拥有稻田面积21.2公顷。该村水利条件较好,群众素有养鱼习惯,为发展稻田养鱼奠定了基础。1994年该村在县水产部门的具体指导下,全面推广了田沟凼、田沟溜式养鱼新技术。全村发展稻田养鱼8.7公顷,占稻田总面积的.40.90%,比去年同期增加30%。养殖稻田已投放夏花草鱼32.5万尾,杂交鲤20万尾, 相似文献
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为充分利用我县近20万亩可养鱼冬围水田,发展稻田养鱼,提高稻田的经济效益。于1983年至1985年进行了“开厢栽秧,沟内养鱼、免耕稻田,鱼稻双丰收”的试验,9块田,11.2亩,1985年总产稻谷.4973.5公斤,亩平445公斤,总产鱼849。7公斤,亩产76公斤,1986tF示范1000亩,稻谷亩产450-500公斤,鱼亩产25—55公斤, 相似文献
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关键种对生态系统结构和功能发挥了重要作用,其变化可以引起群落结构振荡和演替,导致生态系统功能紊乱乃至崩溃,因此,了解生态关键种的长期变化有助于解析整个生态系统演替过程。本研究基于莱州湾1959年、1982年、1993年、2003年和2015年春季(5月)底拖网渔业资源调查数据,构建了莱州湾春季鱼类群落食物网拓扑结构,分析了其关键种的长期变化。1959~2015年莱州湾鱼类食物网包含物种21~46个,摄食关系范围70~296个,食物网拓扑结构密度范围为0.155~0.300,种间关联度0.140~0.182,符合自然条件下群落种间摄食关系。1959~2015年莱州湾鱼类群落关键种如下:1959年为六丝矛尾虾虎鱼(Amblychaeturichthys hexanema)、花鲈(Lateolabrax japonicus)、蓝点马鲛(Scomberomorus niphonius)和黄(Lophius litulon),1982年为鳀(Engraulis japonicus)、黄和小黄鱼(Larimichthys polyactis),1993年为带鱼(Trichiurus lepturus)、鳀和蓝点马鲛,2003年为细纹狮子鱼(Liparis tanakae)、鳀和黄,2015年为细纹狮子鱼、大泷六线鱼(Hexagrammos otakii)和六丝矛尾虾虎鱼;关键种由经济价值较高的花鲈、小黄鱼和蓝点马鲛等演变为细纹狮子鱼、鳀和六丝矛尾虾虎鱼等经济价值较低的种类;同时,关键种的栖息环境也由中上层与底层生境(蓝点马鲛、花鲈、鳀等)演变为底层单一生境(细纹狮子鱼、大泷六线鱼和六丝矛尾虾虎鱼);关键种的这种更替导致食物网拓扑结构向简单化发展,在某种程度上也增加了鱼类群落结构脆弱性。 相似文献
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20 0 1年我们与河北水利厅合作 ,特聘请上海水产大学的专家对我们这里的三座水库进行资源调查 ,专家们认为小海子水库是天然的养蟹基地。这是一个浅碟型平原型水库 ,库底平坦 ,水草丰茂 ,枯水季节生长的水草可达水面 70 %左右 ,底部腐植淤泥层厚 15cm左右 ,水色呈绿褐色 ,透明度在5 0~ 80cm ,日照时间长 ,日照数波动在 12 2 7~2 74 8h ,年平均气温为 13 5℃ ,日平均气温变动在 - 4 7~ 2 8 2℃之间 ,库区最高气温 39 8℃ ,最低 - 13 8℃ ,月平均水温变化为 2 4~ 2 2 9℃之间 ,月平均最高水温在 7月和 8月 ,最低在 12月和 1月。由于水… 相似文献
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C.D. de Silva 《Aquaculture International》1997,5(4):339-349
An electrophoretic analysis of six populations of Oreochromis mossambicus (Peters) and four populations of O. niloticus (L.) from several rivers and a fish hatchery in Sri Lanka was conducted to determine the degree of mixing within and between stocks. Genetic characterization of the O. mossambicus stocks showed that some degree of mixing with O. niloticus occurred in all but two of the populations examined, while in the case of the O. niloticus, all the populations had some degree of mixing of O. mossambicus alleles. Genetic identity calculated using Nei's coefficient gave values ranging from 0.9484 to 0.9895 for O. niloticus populations and 1.0 to 0.9940 for O. mossambicus populations, while interspecies comparisons ranged from 0.7531 to 0.9002. The implications of these results for fisheries management and aquaculture are discussed. 相似文献
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M. W. APRAHAMIAN P. HICKLEY B. A. SHIELDS G. W. MAWLE 《Fisheries Management and Ecology》2010,17(2):93-105
Abstract Inland fisheries in England and Wales have high economic and social values. Managing participation to maximise fishery performance is key to maintaining this status. The capital value of fishing rights for migratory salmonid fisheries is €165 million. Coarse fisheries contribute €1030 million to the economy. The central tenet to increasing participation in recreational salmonid fisheries is that an increase in stock size will result in more anglers accessing the fishery. This was examined for salmon on the rivers Usk and Lune where exploitation restrictions increased the number of salmon available to anglers. On the River Lune, the number of salmon available post‐intervention increased by 66%. There was no significant increase in catch while the number of anglers decreased by 16.3%. On the River Usk, the closure of the net fishery potentially resulted in an additional ~1200 salmon being available. Following closure, there was no significant change in rod catch or in the number of anglers. Increased participation is dependent less upon stock manipulation for coarse fisheries and more upon facilitating the activity. In recent years, urban fishery development programmes have provided improved access to local fishing opportunity. Also, new anglers have been targeted through campaigns such as Get Hooked on Fishing and the Scout Angler Badge. 相似文献
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César Salazar Marcela Jaime Yanina Figueroa Rodrigo Fuentes 《Aquaculture Economics & Management (Blackwell Science)》2018,22(2):151-167
In light of the current depletion of extractive marine resources and the sustainability issues that have arisen in the aquaculture industry, the small-scale aquaculture sector has emerged as a viable and sustainable alternative for generating income. To integrate the small-scale aquaculture sector into the food value chain, understanding the decision-making process to innovate becomes essential. This paper explores the factors underlying both innovation choices and intensity among small-scale aquaculture producers by utilizing exclusive census data from the small-scale aquaculture sector in Chile. The results indicate that education, secure property rights, internet access, participation in organizations, commercialization methods, government instruments, understanding of credit, and social learning promote innovation decisions. We also find that largest producers innovate in more areas, suggesting a role of size for both technological and non-technological innovations. 相似文献
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为研究斑海豹生长规律,达到科学饲养的目的,对大连圣亚旅游控股股份有限公司豢养斑海豹进行体检,获取动物性别、年龄、体质量和体长等信息;通过SPSS 13.0软件对动物的生长曲线、体长-体质量关系和雌雄间生长差异进行分析。试验共获得30头豢养斑海豹的体检数据,雌性11头,雄性19头。统计分析发现:logistic、Gompertz和von Bertalanffy三种模型回归的斑海豹最大体长、体质量依次为167、170、171 cm和153、175、191 kg ;体质量-体长关系为(r2=0.908);研究还发现体长-年龄、体质量-体长间的相关关系模型能够较准确的反映斑海豹的生长规律,而体质量年龄模型准确度较差。控制年龄的协方差分析未发现雌雄斑海豹生长规律间的差异(体长:P >0.05;体质量:P >0.05)。 相似文献
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To validate the involvement of meiobenthos in cellulose breakdown in wetlands, meiobenthos were collected from sediments of
Lake Furen and the Biwase River in Hokkaido Prefecture, the Kako River in Hyogo Prefecture, and the Chinai River in Shiga
Prefecture. Cellulase activities of the meiobenthos were measured by cellulose zymographic analysis using sodium dodecyl sulfate
polyacrylamide gel electrophoresis (SDS-PAGE) gels containing 0.5% carboxymethyl cellulose. The results showed that most of
the Turbellaria, Nematoda, Harpacticoida, and Oligochaeta species exhibited cellulase activity. The molecular sizes of the
cellulase-active bands of the sediments in Lake Furen, the Biwase River, and the Chinai River coincided with those of meiobenthos.
The findings suggest that meiobenthos might play a major function in cellulose breakdown in these wetlands. This paper is
the first to report cellulase activity in meiobenthos and that they are possibly involved in the breakdown of cellulose in
wetlands. 相似文献