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中国海监总队走过了十个光辉的春秋，也经历了许多风风雨雨。中国海监河北省总队成立于1992年6月，其前身是“河北省海洋监察大队”，自成立起就得到了国家海洋局和中国海监总队的关心和呵护。1998年国家正式成立中国海监总队，1999年6月，河北省海洋监察大队更名为中国海监河北省总队。我们经历了1995年和2000年两次省政府机构改革，每次机构改革，在机构、职能、 相似文献
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《海洋世界》2009,(9):8-8
食品商总是认为，那些诱人的美味食物图片可以增强人们的购买欲，但荷兰乌特勒支大学的心理学家弗洛尔·克勒泽却不这么认为——当把一张黑森林奶油蛋糕的图片摆在一个对自己的体重相当在意的女人面前时，她会食欲大增吗？不，图片反而会增强她的自控力。克勒泽和她的同事对54名女学生进行了测试，女学生们事先并不知道测试的目的。研究者给女学生们看巧克力蛋糕的图片，之后询问她们的饮食计划——有巧克力和燕麦曲奇可供选择。结果显示，女学生在看过巧克力蛋糕的图片后，更倾向于选择较健康的食物——燕麦曲奇。克勒泽表示，食物的诱惑并不总是激发食欲上的放纵，反而能提醒人们关注体重、控制饮食行为。当然，这项实验结果来自于想要减肥的女性，它是否具有普适性尚不得而知。 相似文献
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2009年6月8日晚,美国纽约帝国大厦点亮蓝色景观灯,纪念首个"世界海洋日"。如果我们稍微留意就会发现,在此之前,我国曾经确立每年的7月18日为全国海洋日。那么海洋日到底有几个?世界海洋日和中国海洋日的关系如何呢? 相似文献
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自古以来,渔业一直是人类食物的一个重要来源。最早的渔业只是在沿海或滨湖用简单的生产工具采捕野生的鱼虾贝藻,成为人类维持生命的最古老的生产活动之一。后随着造船工业和航海技术的发展,扩大了捕捞水域,由近 相似文献
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最近，俄罗斯黑客从东英格兰大学气候研究机构窃取的材料中获知，全球变暖有可能是某些国家或国际组织捏造的“借口”，想借此操控全球经济运行主体。这些书信资料称，通常被认为是上升的地球平均温度，其实是降低了。 相似文献
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王荣良 《中国海洋大学学报(自然科学版)》1990,(2)
对于三个种群可解模式的生态系统,即一个被捕食和二个捕食系统,二个被捕食和一个捕食系统,三步捕食—食饵系统的食物链,当模式的系数均为常数及周期函数情况,均有人进行过研究。本文进一步研究了这些系数随时间变化而趋于一个定值或在某一常数附近作周期性振荡,并给出容易检验存在唯一全局渐近稳定的正周期解的条件。 相似文献
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<正>3月22日,加利福尼亚大学戴维斯分校的一位科学家指出,2006年联合国粮农组织(FAO)发布的题为《畜牧业的巨大阴影》的报告中有错,那份报告就是后来举世闻名的"牲畜原罪说",该报告称全球碳排放总量的18%来自畜牧业,并"抱怨"全球变暖是因为人们吃牛肉太多,而牛打嗝、放屁都是造成温室气体徒增的重要原因。 相似文献
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[实际上,从海上石油钻井平台产生之日起,人们对这种壮观的技术奇迹就存在着深深的质疑]海上石油钻井平台是20世纪末的技术奇迹.20世纪80年代,海上石油、天然气的勘探和开采总投资巴达7500亿美元,海上石油开采总量己超过同期世界石油总开采量的三分之一.重要的是海上石油开采比陆上石油开采更经济,可为人们提供更廉价的石油. 相似文献
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旋链角毛藻对中肋骨条藻化感作用的影响因素 总被引：1，自引：0，他引：1
在已知旋链角毛藻对中肋骨条藻具有化感作用的前提下,进行了温度、生长时期、光照、细菌等因素对旋链角毛藻化感作用的影响、化感物质的萃取及粗提物对中肋骨条藻的化感效应检验等实验,研究了旋链角毛藻化感物质的性质、降解特点,并初步测定了化感物质的结构。结果表明:旋链角毛藻化感作用与生长时期有关,指数期滤液化感作用强于衰亡期;旋链角毛藻的化感物质在50℃以下保持稳定,光和细菌均引起旋链角毛藻化感物质的降解,且细菌降解强于光降解;旋链角毛藻的乙酸乙酯萃取物具有明显的化感活性,该萃取物在255～260 nm处有特征吸收峰。综合以上结果,推测旋链角毛藻化感物质可能为分解温度在50℃以上的易被光和细菌降解的苯衍生物,从极性上看较易溶于乙酸乙酯。 相似文献
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The influence of prolonged mouth closure on the population dynamics of the caridian shrimp, Palaemon peringueyi and the estuarine isopod, Exosphaeroma hylocoetes, in the littoral zone of temporarily open/closed Kasouga Estuary located on the south-eastern coastline of southern Africa was assessed monthly over the period October 2007 to September 2008. Prolonged mouth closure of the estuary contributed to hypersaline conditions (psu > 35) prevailing throughout the estuary for the last four months of the study. The high salinities coincided with a decrease in the areal extent (up to 80%) of the submerged macrophytes, mainly Ruppia maritima, within the littoral zone of the estuary. Total abundance and biomass values of the shrimp and isopod over the period of investigation ranged from 0 to 14.6 ind m−2, from 0 to 13.3 mg dwt m−2, from 12 to 1540 ind m−2 and from 0.1 to 2.16 mg dwt m−2, respectively. Maximum values of both the shrimp and isopod were recorded in the upper reaches of the estuary in close association with R. maritima. Over the course of the investigation, both the abundance and biomass values of the shrimp decreased significantly (P < 0.05 in both cases) which could be related to reduced habitat availability, R. maritima, that acts as a refuge against fish predation. Additionally, the decrease in abundance and biomass values could be attributed to reduced recruitment opportunities for the shrimp and the cessation of reproduction in the estuarine isopod. The establishment of a link to the marine environment following an overtopping event in September 2008 contributed to a decrease in salinity within the system although no recruitment of either the isopod or shrimp was recorded. 相似文献
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The potential role of generalist herbivores to serve as a source of biotic resistance against algal invasion in marine ecosystems has been poorly examined. The present study investigates the capacity of Mediterranean herbivorous fishes to consume three of the most invasive seaweeds of the Western Mediterranean (Caulerpa racemosa, Lophocladia lallemandii and Womersleyella setacea) and examines vertical and temporal variations of such consumption. Our results show that although fish feed throughout the depth gradient examined (5–35 m), they concentrate in shallow waters, and can consume high amounts of C. racemosa. Such high ingestion of C. racemosa does not appear to be random, since this alga is consistently chosen when offered in pairs with several native species. Conversely, L. lallemandii and W. setacea are barely eaten by fish even though they can be very abundant in the field throughout the year. Our results suggest that fish could be an important controlling agent that has been overlooked in temperate marine invasions, and they may be able to provide certain resistance to C. racemosa invasion. In contrast, they are unlikely to exert any important control effects on L. lallemandii or W. setacea. 相似文献
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中国天竺鲷属鱼类的矢耳石形态特征 总被引：2，自引：0，他引：2
利用采自我国近海的105尾标本,分析了细条天竺鲷、宽条天竺鲷、黑鳃天竺鲷、黑边天竺鲷、垂带天竺鲷、四线天竺鲷、半线天竺鲷、斑鳍天竺鲷等8种天竺鲷属鱼类的矢耳石形态特征。8种鱼类矢耳石前部均较尖,后部略圆钝,背部呈折线状,腹部呈圆弧形,背部中央有缺刻,听沟宽阔;8种鱼耳石长宽比的比值为1.35～1.63,矩形趋近率为0.67～0.77,充实度为14.77～24.99。以上述三种形态学参数为基础进行聚类分析,可将8种鱼类分为3组:细条天竺鲷、宽条天竺鲷、黑边天竺鲷、黑鳃天竺鲷为一组;垂带天竺鲷、四线天竺鲷、半线天竺鲷为一组;斑鳍天竺鲷为一组。耳石听沟边缘走向、宽度以及耳石外部边缘光滑度等轮廓特征在8种天竺鲷属鱼类间呈显著的种间差异。以这些形态特征为基础,编制了8种天竺鲷属鱼类的检索表,检索表表现的种间分类关系特征与聚类分析结果基本一致。 相似文献
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A study of the mesoscale distribution of phytoplankton communities observed along the Portuguese upwelling coast in 1985–1986 made it possible to identify an assemblage composed by the coccolithophores Helicosphaera carteri, Syracosphaera pulchra and Coronosphaera mediterranea. The assemblage was consistently present in the coast in the following years (1991, 1992, 1994, 2003 and 2005) and from 1992 onwards, Rhabdosphaera clavigera was recognised as being part of it, although in low concentrations During late summer, this group of species showed higher affinities with upwelling waters of subtropical origin (ENACWst) on the SW coast. At the end of the upwelling season, in autumn, the assemblage was advected to the NW shelf due to the intensification of the poleward surface circulation or meridional seasonal changes of environmental conditions. The species maximum abundances were not coincident in space: H. carteri developed at the central part of the western coast while blooms of S. pulchra and C. mediterranea generally occurred further south, such as at the upwelling centre of cape S. Vicente. Syracosphaera pulchra blooms were characterised by lower concentrations of C. mediterranea and vice-versa. The above patterns were recurrent along the years but the relative abundance of each species appeared related to the interannual variability of physical conditions as the upwelling. 相似文献
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本研究基于线粒体DNA分子标记NADH脱氢酶亚基1基因(ND1)部分序列分析了印度-西太平洋海域的胡椒鲷属及少棘胡椒鲷属共16种胡椒鲷鱼类的系统进化关系。采用最大简约法及最大似然法构建了系统进化树。进化树上,16种胡椒鲷鱼类共形成两个形态特征截然不同的类群,其中类群一的种类体表具有各种鲜艳的颜色与多变的斑纹,主要分布在西太平洋地区;类群二的种类颜色灰暗单一,少数体表具有暗色斑点与条纹,大多数分布在印度洋地区。此外,进化树上,少棘胡椒鲷属的种类都位于胡椒鲷属的类群一内部,与斑胡椒鲷,暗点胡椒鲷形成的姐妹种有较近的亲缘关系。基于遗传距离的数据,少棘胡椒鲷属与胡椒鲷属间的平均遗传距离小于胡椒鲷属内部种间的遗传距离,显示出少棘胡椒鲷属与胡椒鲷属有非常近的亲缘关系,支持少棘胡椒鲷归类于胡椒鲷属的观点。 相似文献
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J.P. Coelho M. Nunes M. Dolbeth M.E. Pereira A.C. Duarte M.A. Pardal 《Estuarine, Coastal and Shelf Science》2008
The annual total and organic mercury bioaccumulation pattern of Scrobicularia plana and Hediste diversicolor was assessed to evaluate the potential mercury transfer from contaminated sediments to estuarine food webs. S. plana was found to accumulate more total and organic mercury than H. diversicolor, up to 0.79 mg kg−1 and 0.15 mg kg−1 (wet weight) respectively, with a maximum annual uptake of 0.21 mg kg−1 y−1, while for methylmercury the annual accumulation was similar between species and never exceeded 0.045 mg kg−1 y−1. The higher organic mercury fraction in H. diversicolor is related to the omnivorous diet of this species. Both species increase methylmercury exposure by burrowing activities and uptake in anoxic, methylmercury rich sediment layers. Integration with the annual biological production of each species revealed mercury incorporation rates that reached 28 μg m−2 y−1, and to extract as much as 11.5 g Hg y−1 (of which 95% associated with S. plana) in the 0.4 km2 of the most contaminated area, that can be transferred to higher trophic levels. S. plana is therefore an essential vector in the mercury biomagnification processes, through uptake from contaminated sediments and, by predation, to transfer it to economically important and exploited estuarine species. 相似文献
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To investigate feeding habits of juvenile flounder (Platichthys flesus) and turbot (Psetta maxima) in relation to habitat characteristics a field survey with push net sampling was conducted in nursery areas with different ecological characteristics in the northern Baltic proper. Sampling sites were stratified to cover several different habitat types defined by substrate and wave exposure. Apart from flatfishes and epifauna, samples of macrofauna, meiofauna and hyperbenthic planktons were collected from each site together with data on vegetation, depth, salinity, temperature and turbidity. The diet differed between species where flounder diet was dominated by chironomids, copepods and oligochaetes while turbot apart from chironomids had a high incidence of amphipods, gobies and mysids. In both species there was a shift in diet with size, although this shift was influenced by the habitat. Among the environmental variables investigated, wave exposure was found to significantly influence flounder diet. Food preference in the most exposed areas was dominated by oligochaetes and copepods instead of chironomids, which dominated in sheltered areas. This study shows that habitat characteristics can have a major influence on feeding habits of juvenile flatfish. 相似文献