Nonlocal wind-driven fjord–coast advection and its potential effect on plankton and fish recruitment     

Lars Asplin  Anne Gro Vea Salvanes  & Jon Bent Kristoffersen 《Fisheries Oceanography》1999,8(4):255-263

The Bergen Ocean Model (BOM), a three-dimensional physical coastal ocean model, was used for a numerical simulation experiment to investigate short-term effects of wind-generated coastal upwelling and downwelling on the dynamics of adjacent large outer and smaller inner fjords. The effect of the real alongshore wind regime on advection for an idealized fjord topography, resembling Masfjorden, western Norway, is used as an example. This modelling exercise is a supplement to, and its predictions support, the various hypotheses investigated in ecosystem simulation studies of the Masfjorden. The model predicts that coastal winds from the north cause upwelling and transport the upper water layer out from the fjords. Winds from the south cause downwelling and transport the upper water layer into the fjords. The transport is rapid and ≈50% of the upper water layer may be replaced within 1–2 days. Implications of these physical processes for the dispersal and retention of planktonic organisms and the early life stages of fish are discussed. If strong southerly winds occur frequently, this will transport planktonic organisms into the fjord and may increase the carrying capacity for planktivorous fish. In contrast, frequent strong northerly winds may reduce the abundance of planktonic organisms, including the early life stages of marine fish, and thus possibly reduce recruitment to fjord fish populations. Frequent shifts between southerly and northerly winds would cause an exchange of early life stages between neighbouring fjords and thus enhance genetic exchange.  相似文献   

大鳞副泥鳅幼苗敌百虫毒性试验的研究   总被引：1，自引：0，他引：1  

陈有光  段登选  马荣棣  靖莹  于振海 《河北渔业》2011,(5):4-6

在大鳞副泥鳅人工繁殖过程中,发现剑水蚤特别容易在孵化箱内聚积,严重地影响了孵化效果.为了解决生产中出现的问题,进行了大鳞副泥鳅幼苗敌百虫毒性试验.选择敌百虫晶体原液(含量≥90%),试验设计一个空白组和五个浓度梯度试验组,每组放入幼苗30尾,经24 h和48 h的观察后,试验结果:大鳞副泥鳅苗种安全浓度为1.25 mg...  相似文献   

Total lipid and fatty acid composition of brill eggs Scophthalmus rhombus L. relationship between lipid composition and egg quality     

Ismael Hachero Cruzado  Marcelino Herrera  Daniel Quintana  Ana Rodiles  José I. Navas  Antonio Lorenzo  Eduardo Almansa 《Aquaculture Research》2011,42(7):1011-1025

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真蛸人工繁殖及受精卵孵化技术研究初报     

钟建兴  李雷斌  宁岳  刘波  曾武斌 《福建水产》2011,33(5):39-42

真蛸为福建省近年来新兴的海水养殖优良种类,具有较高的营养价值、商品价值和产业化养殖前景。本文报道了福建省水产研究所2008年-2011年真蛸人工繁殖及受精卵孵化结果：127头雌亲蛸经强化培育,共有77头产卵,获卵194×10^4粒,孵出143．4×10^4头浮游幼体。雌亲蛸获产率46．2％～86．7％,卵子受精率75．6％-91．8％,受精卵孵化率77．9％～95．0％。在20．0～22．5℃水温条件下,真蛸受精卵经21～36d开始孵出,孵出后4～6d为孵出高峰,每窝卵开始孵出至孵化结束维持10—16d。  相似文献   

长江中游监利江段鱼卵及仔稚鱼时空分布   总被引：3，自引：0，他引：3  

李世健  陈大庆  刘绍平  范振华  任玉芹  段辛斌 《淡水渔业》2011,41(2):18-24,9

2010年5-7月对长江中游监利江段鱼卵和仔稚鱼的时空分布进行调查,共采集到鱼卵样品9494粒,仔稚鱼样品328422尾,分属8目15科43属51种.结果显示:5-7月鱼卵的平均密度为13.3 ind./100m3,最大密度值87.8 ind./100 m3,主要集中在5月;5-7月仔稚鱼平均密度为61.8 ind./...  相似文献   

Diet fed to brood stock effects the growth of channel catfish (Ictalurus punctatus L) fry     

Megan Gima  Andrew Gima  Menghe Li  Rex Dunham 《Aquaculture Research》2011,42(12):1899-1904

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Artificially cold‐induced quiescent egg viability of the tropical copepod Acartia bilobata (Copepoda,Calanoida)          下载免费PDF全文

Yen‐Ju Pan  Anissa Souissi  Jiang‐Shiou Hwang  Sami Souissi 《Aquaculture Research》2017,48(4):1974-1979

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浙江中北部沿岸春、夏季鱼卵和仔稚鱼种类组成与数量分布   总被引：8，自引：0，他引：8  

周永东  金海卫  蒋日进  张洪亮  张亚洲  潘国良 《水产学报》2011,35(6):880-889

根据2008年4,5,6月在浙江中北部沿岸禁渔区线内45个站位开展的产卵场调查资料,研究分析了该海域鱼卵、仔稚鱼的种类组成和数量分布。结果表明,本海区共出现鱼卵、仔稚鱼64个种类,分别隶属13目36科47属,能鉴定到种的有47种,鉴定到科的有17种。3个航次的调查共采集到鱼卵5 846个和仔稚鱼5 502个。其中4月最少,仅采集到鱼卵366个和仔稚鱼1 445个,分别占鱼卵和仔稚鱼总数量的6.26%、26.26%;5月份共采集到鱼卵1 530个和仔稚鱼1 551个,分别占鱼卵和仔稚鱼总数量的26.17%、28.19%;6月份数量最多,共采集到鱼卵3 950个和仔稚鱼2 506个,分别占总数的67.57%、45.55%,4—6月鱼卵、仔稚鱼的数量呈月递增趋势。鱼卵中石首鱼科未定种最多占10.06%,其次黄姑鱼占6.45%,再次为凤鲚占总数的6.06%。凤鲚仔稚鱼数量最多,占总种类数的34.06%,其次为虾虎鱼科仔稚鱼,占24.25%,再次为鲻科鱼类仔稚鱼,占23.57%。调查发现杭州湾是凤鲚的主要产卵场,其仔稚鱼也主要分布在杭州湾内,少量分布在舟山渔场和鱼山渔场。小黄鱼产卵场主要分布在舟山渔场、鱼山渔场外侧。从产卵时间和渔场分布来看,鱼山渔场是最早集中的水域,随着时间推移,产卵场的中心区向北部水域的舟山渔场转移。研究的海域内重要经济鱼类大黄鱼、小黄鱼、银鲳的鱼卵数量百分比明显下降,由1960年的优势种成为现在的非优势种;主要经济鱼类中鳓、凤鲚所占比例相对增加,但绝对数量有所下降。在某种程度上说明,沿岸水域资源补充量有所减少,这可能与水域环境变化及过度捕捞导致亲体量减少有关。  相似文献   

近30年渤海鱼类种群早期补充群体群聚特性和结构更替          下载免费PDF全文

卞晓东  万瑞景  金显仕  单秀娟  关丽莎 《渔业科学进展》2018,39(2):1-15

基于30余年渤海鱼卵、仔稚鱼历史调查资料的整理分析并结合产卵场补充调查,以1982~1983年周年逐月调查资料为本底,采用多元统计学方法分析30余年渤海鱼类种群早期补充群体群聚特性(物种多样性和关键种群)的季节变化和年代际变化,并掌握结构更替过程中优势种和重要种协同消长规律。分析结果显示,渤海各调查季节(冬季除外)鱼卵、仔稚鱼种类数以及资源丰度指数呈先降后升变动趋势。当前鱼卵种类数仅为20世纪80年代1/2左右,资源丰度不足20世纪80年代的1/10;仔稚鱼种类数和资源丰度仅为20世纪80年代的3/4左右,但冬季仔稚鱼种类数和资源丰度指数呈现上升趋势。各调查时期相同季节鱼卵优势种变化不明显,但仔稚鱼优势种变化幅度超过鱼卵,底层重要经济种类早期补充群体优势度急剧下降;鱼卵和仔稚鱼物种多样性水平在升温季节较高而在降温季节较低,调查期内各季主要呈现先降后升变动趋势。鱼类早期补充群体种类更替现象明显,近年来种类更替率呈现明显加快趋势。各调查时期相同季节各适温类型产卵亲体种数均呈现先降后升变动趋势,但各适温类型种数所占比例和全年综合各适温类型种数所占比例基本稳定。各调查时期相同季节各主要栖所类型产卵亲体种类数也均呈现先降后升变动趋势,全年综合陆架浅水中上层鱼类种数所占比例升高,中底层和底层鱼类所占比例有所下降。近30年在多重外来干扰作用下,渤海鱼类早期补充过程各个关键环节已随其栖息地(产卵场)生境要素发生不可逆变化或变迁。渤海鱼类种群早期补充群体群聚特性和结构更替是环境-捕捞胁迫下鱼类群落内多重生态位的交替失调和渔业资源结构性衰退的具体表现。  相似文献   

Lipid characterization of both wild and cultured eggs of cuttlefish (Sepia officinalis L.) throughout the embryonic development     

A.V. SYKES  E. ALMANSA  A. LORENZO  & J.P. ANDRADE 《Aquaculture Nutrition》2009,15(1):38-53

The present work reports a characterization of mean wet weight and moisture, the lipid class and fatty acid (FA) composition from the total lipids (TL), of both culture and wild eggs of the cuttlefish, Sepia officinalis , throughout the embryonic development. Additionally, reproductive data, such as the number of spawnings, number and mean weight of eggs and duration of spawning period of cultured cuttlefish is provided. Both types of eggs were similar in mean wet weight, moisture content, TL content and lipid composition throughout embryonic development. Females from the cultured group spawned 13 times and laid 8654 eggs in 64 days, with a mean weight of 0.607 ± 0.179 g. A sex ratio of 1.57 (11♀ for 7♂) promoted an individual fecundity of 787 eggs/♀ (the biggest until now on our culture facilities), which might be related to increased bottom areas. The TL increased with day/stage of embryonic development ( P  < 0.05) only in the cultured egg group. However, no differences were found on TL between culture and wild eggs at the same day/stage ( P  > 0.05). Eggs displayed predominant levels of phosphatidylcholine, phosphatidylethanolamine (PE), cholesterol and triacylglycerol at the end of embryonic development. Polar and neutral lipids of both eggs groups remained consistently proportional (∼50% for each lipid fraction) and a significant increase ( P  < 0.05) was observed in phosphatidylserine, PE and free FA throughout the embryonic development. In either egg type and day, 16:0, 18:0, 20:5n-3 and 22:6n-3 accounted for approximately 70 g Kg⁻¹ of all FA and saturated and n-3 totals seemed to have the same proportion in the cuttlefish eggs. The present results suggest that lipids are not used as energetic substrate but as structural components in cuttlefish egg.  相似文献