Estuarine resources use by juvenile Flagfin mojarra (Eucinostomus melanopterus) in an inverse tropical estuary (Sine Saloum,Senegal)     

Ndombour Gning  François Le Loc'h  Omar T. Thiaw  Catherine Aliaume  Guy Vidy 《Estuarine, Coastal and Shelf Science》2010

The Flagfin mojarra, Eucinostomus melanopterus, is a marine spawner whose young individuals are common in the Sine Saloum inverse estuary (Senegal). The species offers the opportunity to study both the use of the estuarine nursery resources and the impact of the particular environment of the inverse estuary on these resources. This will lead to a better understanding of the functioning of the nursery. We investigated the resources used by juvenile Flagfin mojarra by coupling stomach contents and stable isotopes methods.  相似文献   

Cross-shore suspended sediment flux in the salt marsh pioneer zone of Chongming eastern beach in the Changjiang Estuary in China     

WANG Chu  YAO Dongjing  HE Baogen  ZHOU Naisheng  XU Shiyuan 《海洋学报(英文版)》2010,29(6):62-72

Between April 2002 and April 2003, in situ measurements of water depth, current velocity and suspended sediment content were carried out in edge region of East Chongming salt marsh and neighboring bald flat in the Changjiang (Yangtze) Estuary under different weather conditions. Cross-shore suspended sediment flux was calculated and analyzed. The results show that under calm weather conditions, the current velocity process in bald field and salt marsh area varied differently during semidiurnal tidal cycles. Owing to current velocity asymmetry, mean SSC during flood tide phase was 1.8 times higher than that of ebb tide phase. As a result, net onshore sediment flux controlled cross-shore suspended sediment transport process and salt marsh pioneer zone was generally accreting. There was significant positive correlation between total sediment flux and quartic power of maximum water depth. It indicates that tidal ranges dominate suspended sediment transport and sedimentation process in the salt marsh pioneer zone under the calm weather condition. The sedimentation rate on the adjacent mudflat was higher than the salt marsh, which induced stable accreting of salt marsh towards the sea. The wind events enhanced SSC and current velocity during the semidiurnal tides. And the remarkable onshore net sediment flux could occur on the high marsh and mudflat close to the marsh fringe during the short period under the rough weather condition.  相似文献   

美洲黑石斑鱼含肉率及肌肉营养成分分析   总被引：9，自引：0，他引：9  

党冉  竺俊全  邱新志 《海洋学研究》2010,28(2):60-66

利用常规肌肉营养测试方法,测定分析了美洲黑石斑鱼的含肉率及肌肉营养成分。测定结果显示,美洲黑石斑鱼含肉率平均值为(73.71±1.93)%,肌肉(鲜样)中粗蛋白、粗脂肪、水分和粗灰分含量分别为(19.09±1.34)%,(6.14±1.76)%,(71.86±1.58)%和(1.32±0.17)%;美洲黑石斑鱼肌肉中被测出的常见氨基酸(色氨酸未测定)有17种,其中包括7种必需氨基酸、2种半必需氨基酸和8种非必需氨基酸,其氨基酸含量占鲜体质量的百分比分别为(8.27±0.21)%,(1.84±0.08)%和(10.15±0.31)%,17种氨基酸总含量为(20.26±1.13)%(鲜样)。谷氨酸(Glu)含量占鲜体质量的百分比最高,为(3.27±0.16)%,其次是天冬氨酸(Asp)和赖氨酸(Lys),胱氨酸(Cys)含量占鲜体质量的百分比为最低,仅为(0.27±0.01)%。4种鲜味氨基酸含量占干样的(29.32±0.14)%。鲜样的美洲黑石斑鱼必需氨基酸总量占氨基酸总量的比值为40.82%,干样的为40.81%;鲜样的必需氨基酸总量与非必需氨基酸总量的比值为81.48%,干样的为81.43%,其构成符合FAO/WHO的标准。同时计算出的美洲黑石斑鱼肌肉蛋白质氨基酸评分(AAS)均大于1,化学评分(CS)均大于0.7,必需氨基酸指数(EAAI)达到91.18,高于多数海产经济鱼类,说明它能为人体提供大量必需氨基酸,且其组成接近人体的氨基酸需要量模式。美洲黑石斑鱼肌肉中主要含有16种脂肪酸,其中饱和脂肪酸(SFA)7种,含量占肌肉脂肪酸总量的(38.66±1.22)%;不饱和脂肪酸(UFA)9种,含量占肌肉脂肪酸总量的(61.36±0.98)%,其中单不饱和脂肪酸(MUFA)5种,多不饱和脂肪酸(PUFA)4种。多不饱和脂肪酸中的人和动物生长发育必需的脂肪酸EPA和DHA含量,分别占总脂肪酸的(9.02±0.59)%和(11.73±0.43)%。-ω3族与-ω6族PUFA总量的比值为5.30。分析表明,美洲黑石斑鱼肌肉含肉率高,含有较多的粗蛋白和粗脂肪,氨基酸总量及鲜味氨基酸含量均较高,是一种优质蛋白源;美洲黑石斑鱼肌肉富含PUFA,尤其是EPA和DHA含量丰富,并且∑n3/∑n6值较高,因而具有较高的食用营养价值和保健功效,是一种具有广阔市场前景的优良养殖品种。  相似文献   

估算混合植被叶绿素含量的理想波段分析   总被引：2，自引：1，他引：1  

高彦华  陈良富  周旭  李丽  柳钦火  田国良 《遥感学报》2009,13(4):623-638

应用Lopex数据库评价了19个波谱指数对物种的敏感性, 分析了叶绿素含量与波谱反射率以及波谱导数的相关性, 目的在于探寻对叶绿素含量变化的敏感性, 对物种和叶片结构变化不敏感的理想波段, 应用大尺度遥感数据估算混合植被冠层叶绿素含量。分析结果表明：红边指数对混合植被的叶绿素含量具有较好的指示作用;估算冠层叶绿素含量的理想波段为698—710nm附近较窄的波段范围;对于波谱导数, 估算混合植被叶绿素含量的理想波段范围为720—735nm和535—550nm附近波谱导数。  相似文献   

遥感物理教学内容设计与探讨     

田玉刚  宋妍 《地理空间信息》2009,7(4):149-150

分析了目前国内遥感物理本科课程的开设情况及存在的问题,针对遥感科学与技术本科专业的培养目标,并考虑与后续课程的联系,对遥感物理教学内容进行了设计与探讨。  相似文献   

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米仁欢  钟敏  闫昊明  彭鹏  江敏 《大地测量与地球动力学》2009,29(5):58-61

???????????????о???2001??2007????????й???????????????????仯????????????ECCO?????????????????????????????????????о???????????????Χ??????????????÷?????????ECCO????????????????ú?á?  相似文献   

测定锰矿石中低含量钒的试验     

江桂莲  徐广成  张玉强  李兆燕  马明 《山东国土资源》2009,25(11):38-40

化学分析工作要求测试快速、准确,低含量钒的测定因流程长,操作复杂,不易掌握,影响了推广使用。该试验采用分光光度法针对锰矿石中钒的测定进行了改进,取得了良好的效果。该法采用过氧化钠-碳酸钠熔融、水浸取,吸取清液依次加入硝酸、磷酸、钨酸钠溶液生成可溶性的黄色磷钨钒酸络合物,测量其吸光度,大大提高了分析效率。  相似文献   

Study of elastic-plastic damage model of cement consolidated soil with high organic content          下载免费PDF全文

CHEN Huie  WANG Qing  CAI Keyi 《世界地质(英文版)》2009,12(1):17-21

On the basis of elastic-plastic damage model of cement consolidated soil, the authors took organic contents into reasonable damage variable evolution equation in order to seek relation between the organic contents and parameters in the equation, and established the elastic-plastic damage model of cement consolidated soil considering organic contents. The results show that the parameters change correspondingly with difference of the organic contents. The higher the organic contents are, the less the valves of the parameters such as elastic modulus (E), material parameters (K, n) and damage evolution parameter (ε) become, but the larger strain damage threshold value (εd) of the sample is. Meanwhile, the calculation results obtained from established model are compared with the test data in the condition of common indoors test, which is testified with reliability.  相似文献   

长江口水域悬沙含量时空变化卫星遥感定量研究方法探讨   总被引：3，自引：0，他引：3  

李婧  高抒  汪亚平 《海洋学报》2009,31(4):167-175

悬沙含量是反映细颗粒物质在水层中的输运和再悬浮过程的重要指标,对沉积环境和沉积过程的研究有着非常重要的作用,是联系动力作用和地貌演变的纽带[1].细颗粒物质是营养盐、有机物和重金属输送的载体,因此研究细颗粒物质的运移对河口和海洋环境及生态的影响有着重要的意义[2].由于河口地区同时受到河流径流和潮流的影响,径流的水沙输运、潮流和波浪等的动力都对悬浮泥沙含量有影响.河口地区悬沙含量既可以指示沉积物来源、输运量的变化,又可以显示沉积动力作用的变化,这两种影响因素的时间尺度不同,但它们会共同影响悬沙含量的大小和分布.在我国长江等大河每年的水沙输运量十分巨大.  相似文献   

Overlooked small and juvenile piscivores dominate shallow-water estuarine “refuges” in tropical Australia     

Ron Baker  Marcus Sheaves 《Estuarine, Coastal and Shelf Science》2009

A model was developed to estimate the relative impacts of different functional groups of piscivores on the shallow-water estuarine nursery assemblage of tropical north-eastern Australia. Data on variability in the occurrence, number and type of fish in the diet of different piscivores was combined with estimates of the abundance of each group. The model predicts that previously overlooked small and occasional or ‘minor’ piscivores, such as sillaginids, ambassids, sparids and small juvenile carangids, inflict mortality on new recruits to shallow-water nursery habitats that is orders of magnitude greater than that imparted by more conspicuous larger piscivores. Because of their high abundance, a shift in the diet of minor piscivores to prey on new recruits results in a massive increase in the consumption of fish prey by the piscivore assemblage as a whole. Even if the evidence that minor piscivores switch to target new recruits was rejected, the model shows that the highly abundant minor piscivores must still exert a significant proportion of predation mortality experienced by recruiting fishes. As a broad functional group, minor piscivores occur in most aquatic systems around the globe and are likely to play an important but largely overlooked role as predators that shape communities through predation on critical early life stages of other fishes.  相似文献