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751.
大鹏湾夜光藻赤潮的营养动力学模型 总被引:1,自引:0,他引:1
根据大鹏湾夜光藻Noctilucascintillans赤潮发生要素的结构关系,利用生物种群生态学和营养动力学的原理,提出夜光藻-硅藻-营养物质三者相关的动力学模型,模型中的参数将体现海况环境的有关因素。文中利用微分方程动力系统理论对模型作出定性分析,给出赤潮发生与否的某些判别条件;并根据1991年3月1日一4月30日大鹏湾所发生的夜光藻赤潮数据分别对1次赤潮全过程和有连续3次赤潮的情形进行了有效的数值模拟,所得结果对赤潮的预测预报研究有一定的参考价值。 相似文献
752.
对南海6种不同种类或不同生长海域的马尾藻进行营养成分分析,然后与海带和紫菜比较,进行营养学评价。结果表明,马尾藻含有丰富的膳食纤维、褐藻淀粉、矿物质和维生素以及优质的高度不饱和脂肪酸和合理的必需氨基酸组成,其中必需氨基酸的化学评分为80~88之间,远高于海带和紫菜,其余成分与海带、紫菜接近,可作为保健食品和药物的优质原料 相似文献
753.
754.
枝角类在水产养殖中的应用 总被引:4,自引:0,他引:4
本文就枝角类与其它活饵的营养成份进行了比较,并阐述了枝角类在海淡水苗种培育和水产饲料中的应用效果、意义,以及蒙古裸腹溞的培养问题. 相似文献
755.
Nancy ArandaCirerol Jorge A. Herrera-Silveira Francisco A. Comín 《Estuarine, Coastal and Shelf Science》2006,68(3-4):445
This work is the beginning of a coastal water quality monitoring program to establish the baseline for the implementation of an integrated coastal management of the Yucatán Peninsula tropical ecosystem. Coastal water quality is affected by the increasing economic development. This area has no rivers because of its karst geomorphology, and the coastal freshwater comes from springs or seeps. Coastal water quality was studied in four towns from January to December 2000. Statistically significant differences among water quality variables and processes are discussed. Along with groundwater discharge, domestic and shrimp farming sewage are the main sources of nutrients, predominantly of nitrogen and silica. Salinity dilution is used to estimate the groundwater fraction that influences each area in northwestern Yucatán. 相似文献
756.
Eight common red tide species including the Dinoflagellates Alexcandrium tamarense,Prorocentrum minimum , Prorocentrum mican , Diatoms Skeletonema costatum , Cerataulina pelag-ica, Leptocylindrus minimus, a Raphidophyte Heterosigma akashiwo and a Chrysophyte Isochrysis galbana were chosen to study the effect of four nitrogen substrates (NO_3 - N, NH_4 - N, Urea - N, Mixed - N) on the growth of these algae. After two transfers, the results showed that at N concentration of 550 μmol,, NO_3 - N was the best nitrogen source among these four nitrogen substrates; Urea - N and Mixed - N were also good for the growth of most algae, but not as good as NO_3 - N for some species; NH_4 - N inhibited the growth of all these species except H. akashiwo. At concentrations of 280 and 50 μmol experiments on the growth of I. galbana , P. minimum and L. minimus in NH_4 - N and NO_3 - N substrates were also performed. The results showed that the growth rates of I. galbana were not significantly different from each other in 相似文献
757.
In order to determine the relative aging slams of upwelled or vertically mixed water in the northern Taiwan Strait, a recently developed method of calculating the degree of nutrient consumption (DNC) was employed. Upwelling was detected at a water depth of about 75m in summer. Bottom waters in the aphotic zone and newly-upwelled waters in the euphotic zone were found to be low in terms of their DNC. In general, a low DNC was noted alongside the other traditional upwelling indicators, such as lower temperature and degree of oxygen saturation, but higher salinity, apparent oxygen utilization, nutrient contents and chlorophytt-a. Enhanced vertical mixing, but without an apparent upwelling signal, was detected near the same location in winter. 相似文献
758.
福建红树林区4种海藻的营养成分 总被引:1,自引:0,他引:1
主要对福建红树林区4种海藻(扁浒苔Enteromorpha compressa,混合卷枝藻Bostrychia mixta,鹧鸪菜Caloglossa leprieurii,节附链藻Catenella impudica)的营养元素和氨基酸含量等进行研究.结果表明:(1)福建红树林区 4种海藻Fe,Mn含量显著高于一般海藻的平均浓度;Ca含量则普遍低于一般海藻的平均浓度;P,K,Mg含量则高于或低于一般海藻的平均浓度;(2)福建红树林区4种海藻总氨基酸含量(TAA)由高到低依次为(干重):扁浒苔265.89mg/g,混合卷枝藻211.96mg/g,鹧鸪菜189.53mg/g,节附链藻111.10mg/g;而必需氨基酸含量(EAA)由高到低依次为:混合卷枝藻87.42mg/g,扁浒苔82.92mg/g,鹧鸪菜73.62mg/g,节附链藻34.41mg/g;(3)在3和6月,对生长在秋茄板状根上和岩石面上的鹧鸪菜营养成分比较,前者的总氨基酸和必需氨基酸含量均大于后者;而元素含量则有不同变化. 相似文献
759.
760.
The mechanism by which nutrient is supplied to a warm-core ring (WCR) was investigated in order to understand the greater
productivity of WCR than that of the Kuroshio, where the WCR originattes. A single WCR was observed in January and May, 1997.
The thermostad (a layer of isothermal and isohaline water) of the WCR had different properties from January to May, the differences:
Δwater temperature: −0.698°C, Δsalinity: −0.048, Δsigma θ: +0.072, Δnitrite+nitrate-N: +1.83 μM, Δphosphate: +0.011 μM and
Δsilicate: +3.2 μM. We examined three possible mechanisms for nutrient supply to WCR in winter, namely: 1) inflow of the Oyashio
surface water into WCR; 2) isopycnal mixing with Oyashio water; 3) entrainment of the water below the WCR into the WCR. The
results were as follows: 1) When the decrease of salinity was due to the inflow of the Oyashio surface water, the increase
of nutrients (nitrite+nitrate-N, phosphate-P and silicate-Si) was estimated to be only 17–27% of the observed increase. 2)
When the decrease of salinity was due to isopycnal mixing, the increase of nutrients was estimated to be 30–42% of the observed
increase. 3) When the decrease of salinity in the WCR in May was due to entrainment of the water below the WCR in winter by
convection, the mixing depth was calculated be 620 m according to the salt budget. The increase of nutrients in this case
was calculated to be 82–95% of the observed increase. The main mechanism of nutrient supply to WCR was concluded to be due
to the entrainment of the water below the WCR by winter mixing.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献