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近些年来,葫芦岛市浅海筏式养殖海湾扇贝发展迅速,仅绥中县止锚湾海区已养殖两万多台筏,但是由于缺乏科学指导,缺乏对水产养殖生态环境了解,只是受暂时和局部利益的驱动.因而带有很大的盲目性,致使目前面临许多严重生态问题.如病害、超负荷养殖、扇贝小型化、污染严重等. 相似文献
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近几年来,葫芦岛市浅海浮筏式养殖海湾扇贝发展迅速,仅绥中止锚湾海区已养殖2万多台筏.伴随着养殖面积不断扩大,扇贝小型化现象日趋严重,生长不良,规格小,使养殖业蒙受很大的经济损失.究其原因错综复杂,即有生物因子,高温、低温和强热带风暴等诸多因素影响,也有养殖环境质量下降(产生自身污染),养殖贝类遗传质量下降(养殖贝类种群退化),养殖容量过大,生态失衡(局部海区负荷过大),养殖工艺不合理以及粗放型的经营管理等方面的因素.但养殖技术落后,管理水平低也是不容忽视的重要原因.针对这些问题,本文提出如下几点改进意见,供参考. 相似文献
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根据2018年9月10日对昌黎县海湾扇贝养殖海域的水质调查数据,分析了该海域水体基本理化因子,并采取营养状态质量指数评价法(NQI)、营养状态指数法(E)、有机污染指数评价法(A)及内梅罗环境质量综合评价指数法(P)对水质进行综合评价。结果表明:昌黎县海湾扇贝养殖海域各站位的水温、盐度、pH、DO、COD和DIP含量均符合海湾扇贝养殖水质标准,但是DIN含量严重超标。评价结果显示昌黎县海湾扇贝养殖海域已受到有机污染且水体呈现富营养化,养殖区内比养殖区外情况更为严重,其中N7站位最甚。DIN为该海域主要污染因子。 相似文献
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止锚湾海域筏式养殖海湾扇贝防止褶牡蛎附着试验 总被引:6,自引:1,他引:6
本文叙述了笔者在止锚湾海域进行筏式养殖3海湾扇贝防止褶牡附着试验的过程和结果,提出了预报该海域褶牡蛎繁殖高峰期和附着高峰期,采取在褶牡繁殖高峰前和附着高峰期之后分苗入养成笼,从而降低了海湾扇贝壳体上褶牡蛎的附着量和提高海湾扇贝的商品率;试验与生产相结合,利用试验结果来指导生产,进一步验证了这一处理方法在海湾扇贝筏式养殖过程中的可行怀。 相似文献
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桑沟湾养殖海域营养状况及其影响因素分析 总被引:10,自引:0,他引:10
桑沟湾营养现状调查结果表明,桑沟湾营养状况不仅受沿岸排放水的影响,而且大面积的海带和扇贝养殖对于营养盐的补充与消耗也有较大的影响,特别是在扇贝养殖区水域,富营养化水平较高。由N/P比值计算结果表明,从整个海湾看,冬季无机氮显得相对紧缺,而其他季节无机磷则显得相对紧缺。但从局部海域看,各季节扇贝养殖区无机磷显得相对紧缺。而在扇贝和海带混养区的1月,以及在海带单养区养殖海带期间的1月和4月无机氮显得相 相似文献
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海湾扇贝(Artgopectens irradias),又称大西洋内湾扇贝,原产于美国东海岸。1982年由中国科学院海洋研究所张福绥先生引进中国,并开展人工养殖。现将浅海域吊养海湾扇贝的几个关键技术总结如下: 相似文献
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昌黎县是河北省及国内第一海湾扇贝养殖大县,有十几年的养殖历史.2009-2011年昌黎县沿海海域连续发生由微型鞭毛藻暴发引起的赤潮,对当地海湾扇贝造成了相当大的影响.笔者参加了三年来赤潮发生过程的调研和海湾扇贝养殖的全过程,总结经验教训,并提出一些应对措施,以利人们正确认识、研究此类赤潮,使海水养殖业健康发展. 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